ArticlePDF Available

Environmental impacts of examination gloves made of natural rubber and nitrile rubber, identified by life‐cycle assessment


Abstract and Figures

Medical examination gloves made of natural rubber (NR; powdered and non‐powdered) and synthetic nitrile rubber (NBR) were compared in terms of their environmental impact using life cycle assessments spanning material extraction, transportation to the glove production factory, the production process, and disposal by total incineration. ReCiPe Midpoint (H) V1.13/World Recipe H life cycle assessment method implemented using the SimaPro, was used. Single scores of each glove type and stage were determined by using weighting factors specifically obtained from a 2014 survey in Thailand. With current technologies, the overall environmental impact, or the total single score, of NR gloves was higher than of NBR gloves, because the glove production stage of NR gloves required more energy and sulfur use. In addition, the overall environmental impact of both types of gloves was found to be lower if powder coating was used rather than chlorination to reduce stickiness, and if glove production relied on natural gas for energy rather than coal. The single score approach revealed the hotspots for potential improvements for each glove type.
This content is subject to copyright. Terms and conditions apply.
Environmental impacts of examination gloves made of
natural rubber and nitrile rubber, identified by life-cycle
Supatra Patrawoot
| Thierry Tran
| Marisa Arunchaiya
Voranuch Somsongkul
| Yusuf Chisti
| Nanthiya Hansupalak
Department of Chemical Engineering, Kasetsart University, Bangkok, Thailand
Center of Excellence on Petrochemical and Materials Technology, Kasetsart University, Bangkok, Thailand
Qualisud/ELSA Group, Université Montpellier, CIRAD, Institut Agro, Université d'Avignon, Université de La Réunion, Montpellier, France
Alliance of Biodiversity International and the International Center for Tropical Agriculture (CIAT), Cali, Colombia
Department of Materials Science, Kasetsart University, Bangkok, Thailand
Department of Industrial Chemistry, King Mongkut's University of Technology North Bangkok, Bangkok, Thailand
School of Engineering, Massey University, Palmerston North, New Zealand
Center for Advanced Studies in Industrial Technology, Kasetsart University, Bangkok, Thailand
Specialized Center of Rubber and Polymer Materials for Agriculture and Industry, Kasetsart University, Bangkok, Thailand
Nanthiya Hansupalak, Department of
Chemical Engineering, Kasetsart
University, Bangkok 10900, Thailand.
Funding information
National Research Council of Thailand;
Thailand Research Fund, Grant/Award
Number: RDG5850025
Medical examination gloves made of natural rubber (NR; powdered and non-
powdered) and synthetic nitrile rubber (NBR) were compared in terms of their
environmental impact using life cycle assessments spanning material extraction,
transportation to the glove production factory, the production process, and dis-
posal by total incineration. ReCiPe Midpoint (H) V1.13/World Recipe H life
cycle assessment method implemented using the SimaPro, was used.
Single scores of each glove type and stage were determined by using weighting
factors specifically obtained from a 2014 survey in Thailand. With current tech-
nologies, the overall environmental impact, or the total single score, of NR
gloves was higher than of NBR gloves, because the glove production stage of NR
gloves required more energy and sulfur use. In addition, the overall environmen-
tal impact of both types of gloves was found to be lower if powder coating was
used rather than chlorination to reduce stickiness, and if glove production relied
on natural gas for energy rather than coal. The single score approach revealed
the hotspots for potential improvements for each glove type.
glove life-cycle-analysis (LCA), glove production, latex gloves, medical gloves
Received: 14 December 2020 Revised: 10 February 2021 Accepted: 13 February 2021
DOI: 10.1002/pls2.10036
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided
the original work is properly cited.
© 2021 The Authors. SPE Polymers published by Wiley Periodicals LLC. on behalf of Society of Plastics Engineers.
SPE Polymers. 2021;2:179190. 179
Examination gloves are widely used in healthcare facili-
ties, laboratories, food factories, and diverse other busi-
nesses. Such gloves are designed for single use and
disposal to prevent transmission of infection. The global
demand for these gloves was around US$6 billion in 2019
and is expected to grow at a compounded annual rate of
10.6%11.2% until 2027 at least. The largest markets for
examination gloves are North America and Europe.
The examination gloves used worldwide are produced
from either natural rubber (NR) or synthetic rubber
(e.g., nitrile, vinyl, and neoprene rubbers). NR is the
dominant material for producing gloves, followed by
nitrile rubber. These two materials are forecast to domi-
nate the global market for the foreseeable future.
Irrespective of the type of rubber used in their pro-
duction, examination gloves are available with and with-
out an internal powder coating of cornstarch. Powder
acts as a lubricant making coated gloves easier to put on
and remove. The powder also absorbs sweat, providing a
comfortable feel to the user,
although the use of pow-
dered gloves in medical facilities has been banned in sev-
eral countries (e.g., USA, Germany, Philippines, Japan,
and Saudi Arabia) because of concerns relating to con-
tamination and allergenic reactions in patients. This has
increased the demand for powder-free gloves. The
powder-free gloves are produced by two different
methods, either chlorination or polymer coating.
chlorination process usually involves multiple washings
of the powdered gloves with a solution of hypochlorite
and hydrochloric acid. During washing, the surface of the
rubber film is oxidized, decreasing friction, or tackiness
of the surface. In the alternative polymer coating method
of reducing surface stickiness, a polymer (e.g., acrylic
polyurethane, and silicone polymers) is used to coat
inner surface of the gloves,
and this may be followed
by chlorination.
Although NR examination gloves presently dominate
the global market and are expected to retain this domi-
nance at least in the near term,
the use of nitrile gloves
is growing rapidly. This preference for nitrile gloves is
driven by the presence of potentially allergenic proteins
on the surface of NR gloves.
These proteins occur nat-
urally in the latex harvested from the rubber tree and can
be removed with additional processing.
notwithstanding, NR gloves have superior barrier prop-
erty, elasticity, resistance to sharp objects, and strength
than nitrile gloves
and are preferred in many
In addition to performance and price, the consumer
preference is increasingly influenced also by the environ-
mental impact of a product. Consequently, environmental
impacts are being assessed and used in product market-
ing. Environmental impact of a product can be calcu-
lated using a cradle-to-grave life cycle assessment (LCA).
LCA is an environmental management tool that
evaluates inputs, outputs, and potential environmental
impacts associated with a product during its entire life
Although separate LCA of NR gloves and nitrile
gloves have been used to assess their environmental
the specific types (e.g., medical examina-
tion, food processing, or industrial grade) of gloves used
in these evaluations were not specified.
LCA is
affected by the glove type because, depending on
intended application, their production requires different
amounts of raw materials (e.g., rubber and other
chemicals) and energy. Furthermore, earlier LCAs used
dissimilar functional units and focused on different envi-
ronmental impacts. Consequently, the environmental
performance of NR and nitrile gloves cannot be quantita-
tively compared based on the available reports.
present study fills this gap.
The present work assesses midpoint environmental
impacts of NR examination gloves (powdered and
powder-free) and powder-free nitrile examination gloves
using a LCA spanning the extraction of the raw materials
and energy, the production process, and disposal of the
used gloves. The actual use stage of the glove was
excluded from LCA as there were no inputs or emissions
associated with it. ReCiPe Midpoint (H) V1.13/World
Recipe H method and the SimaPro software were
used for the characterization and normalization steps. To
provide multiple criteria for decision-making, all mid-
point environmental impacts were aggregated into a sin-
gle score by using weighting factors established by a
survey conducted in Thailand in 2014.
data were collected on-site from two glove manufacturers
in Thailand. The data obtained enabled a robust compari-
son of the environmental impacts of NR and nitrile
examination gloves and of powdered and powder-free NR
gloves. Medical examination gloves referred to simply as
glovesin the remainder of this work, were the specific
focus of this study. Hotspots of environmental impact
were identified and options were explored for reducing
these impacts.
2.1 |The methodological approach
LCA comprised of the following four phases: Goal and
scope definition, the life cycle inventory (LCI) analysis,
environmental impact assessment, and interpretation.
The environmental impacts calculations were conducted
using the ReCiPe Midpoint (H) V1.13/World Recipe H
methods and SimaPro software (www.
2.2 |Goal, scope and system boundaries
The goals of the study were to evaluate cradle-to-grave
environmental impacts of: (1) Four glove types produced
at two factories; and (2) switching from coal to natural gas
in production of NR and nitrile gloves. The glove types
evaluated were: (1) Powder-free nitrile gloves produced at
Factory 1 (NBR_PF1); (2) powder-free NR gloves produced
at Factory 1 (NR_PF1); (3) powder coated NR gloves pro-
duced at Factory 2 (NR_PP2); and powder-free NR gloves
produced at Factory 2 (NR_PF2). The powder coating
material was corn starch in all cases. For comparison of
different products, all data were normalized to a common
basis of a functional unit (FU) of 100 pieces of gloves.
The relevant processes and systems boundaries are
shown in Figure 1. The production technologies and
processes for NR gloves at the two factories were differ-
ent, as summarized in Figure 1 (see caption). Route
1 (marked on the flow diagram in the orange box;
Figure 1) was the production path of NR_PF1 and
NBR_PF1 at Factory 1, whereas at Factory 2, Routes
2 and 3 applied to NR_PP2 and NR_PF2, respectively.
The system boundaries of all four glove types included
the transportation of materials to a glove factory, glove
production, and disposal (Figure 1). For production of
raw materials, two cases were considered: (1) For nitrile
gloves, the system boundaries included production of raw
materials (acrylonitrile butadiene rubber latex, or nitrile
latex for short), based on Ecoinvent LCI of acrylonitrile,
butadiene, and styrene
; and (2) for NR gloves, the sys-
tem boundaries included the agricultural production of
fresh NR latex (dry rubber content, or DRC, of 30%) and
production of concentrated NR latex with 60% DRC
(Figure 1).
Furthermore, after vulcanizing and cooling steps, the
production routes for NR_PF1, NR_PF2, and NR_PP2
were different as shown by the numbered arrows in
Figure 1 (orange box). NR_PF1 underwent the polymer
FIGURE 1 The common system boundaries for all four gloves comprised the glove production and disposal processes. For natural
rubber (NR) gloves, the system boundaries for agricultural production of NR latex and production of concentrated NR latex were added.
Route 1 (marked on flow diagram in the orange box) was the production path of powder-free NR gloves from Factory 1 (NR_PF1) and
powder-free nitrile gloves from Factory 1 (NBR_PF1), whereas Routes 2 and 3 were of powder coated NR gloves from Factory 2 (NR_PP2)
and powder-free NR gloves from Factory 2 (NR_PF2), respectively. Dashed lines specify boundaries for rubber plantation, concentrated NR
latex factory, glove factory, and the used glove disposal operation
coating and chlorination treatments before drying, strip-
ping, inspection, and packaging (Route 1, Figure 1),
whereas NR_PP2 and NR_PF2 underwent powder dip-
ping together (Route 2, Figure 1). However, after being
stripped from the forming molds (or formers; Figure 1),
only NR_PP2 went straight for inspection and packaging,
whereas NR_PF2 went to chlorination treatment (Route
3, Figure 1). Finally, the production route for NBR_PF1
was nearly identical to that of NR_PF1, except that the
gloves underwent chlorination only, without polymer
The disposal stage took into account only the waste
gloves (excluding packaging boxes because they could be
recycled). Disposal was by incineration, a common prac-
tice for used medical gloves.
The impacts of infrastruc-
tures (factory buildings, machinery) were not included in
this analysis as their contributions were deemed insignifi-
cant in relation to the materials and energy consumed
during the 2025 years lifetime of a factory.
2.3 |Life cycle inventory
Inputs and outputs for each system boundary were calcu-
lated for 1-year of production of gloves and were then
normalized to a FU of 100 pieces of gloves. The input
output data for glove production were collected via onsite
interviews with staff of the two factories. LCI of the four
glove types were proprietary and protected by confidenti-
ality agreements with the two factories involved, but life
cycle inventories for similar products have been reported
The inputoutput data for agricultural production of
fresh NR latex and production of concentrated NR latex
were retrieved from Thai National Life Cycle Inventory
The LCI of production and concentration of
fresh NR latex are confidential, but LCI data for similar
products are available in the literature.
LCI of acrylonitrile butadiene rubber latex, or nitrile
latex, was not available in Thai National Life Cycle
Inventory Database,
but the major components of
nitrile latex (i.e., acrylonitrile and butadiene) are similar
to those of ABS (acrylonitrile butadiene styrene) plastic.
Therefore, the LCI of nitrile rubber was estimated by
excluding styrene from the LCI of ABS retrieved from
Thai National Life Cycle Inventory Database.
Generic data (e.g., transportation vehicles, chemicals)
were retrieved from Ecoinvent ( All
chemicals and packaging used in the glove production,
except latexes, were assumed to be transported from cen-
tral Bangkok to each glove factory. Both NR and nitrile
rubber latexes came from provinces located near the two
Factory 1 produced powder-free NR gloves and
powder-free nitrile gloves by using the same production
lines, but at different times. Similarly, Factory 2 produced
powder-free NR gloves and powdered NR gloves by using
the same production lines, but at different times. The
data on water and energy (electricity and fuel) use of
each factory were based on the monthly bills for the year
of data collection. As the factories did not record water
and energy use separately for each type of glove, these
data were estimated for each factory based on its total
consumption and the quantities (number of pieces) of
each glove type it produced in the year of LCI collection.
The process wastewater in each factory was screened
to remove rubber scrap and then released into an open
biological treatment lagoon. The treatment involved
anaerobic fermentation of the organic matter and released
methane and carbon dioxide gases into the atmosphere.
The treated water from Factory 1 was fed to a water
spraying system to improve dust control in the coal work-
ing area. During spraying, some water evaporated and
some percolated into the ground. The quantity of water
seeping into the ground and any pollutants it may have
leached from the coal dust into the soil, could not be
evaluated reliably. In addition to the water seeping into
the earth, water also left the system boundary as vapor
during drying processes and other activities in the fac-
tory. As the compositions in the water leaving the system
boundary were not known, the water discharge data cell
in SimaPro was left blank, implying no environmental
contribution from the water discharged.
After treatment, the water discharged from Factory
2 had a chemical oxygen demand within the regulatory
norms for such factories in Thailand, and was released to
a natural water source outside the factory boundary.
There was no metered record of water discharge and
therefore it was taken to be 50% of the water entering the
factory perimeter. Thus, the remaining 50% of the input
water left the boundary as vapor from drying processes,
as was the case in Factory 1.
The solid waste in both factories was the gloves that
failed quality tests and rubber scrap retrieved from the
wastewater. The solid waste was sold to a third party who
burnt it to recuperate heat for other processes. Thus, the
total environmental impact of the glove production had
to be divided, or allocated, to the gloves passing the qual-
ity tests and those in the solid waste. The allocation of
environmental impacts between the product and the
waste was performed on a mass basis. The mass of waste
gloves in each factory was approximated to be 3% of the
total mass of gloves produced per year. Thus, the gloves
passing the quality tests were assigned 97% of the total
environmental impact and the waste gloves were
assigned 3% of the total environmental impact.
Emissions to air from the glove factories were mainly
a consequence of the fuel burnt. Factory 1 burnt coal
while Factory 2 used natural gas. In addition, there were
emissions (CH
and CO
) from open wastewater treat-
ment lagoons at both factories.
Waste gloves in this study were treated as infectious
waste. Such waste can be disposed by incineration, or
other methods.
The ash produced is handled as if it
were municipal solid waste.
For disposal of infectious
waste by methods other than incineration, additional
tests are required to demonstrate destruction of patho-
gens. Hence, in Thailand waste medical gloves are mostly
disposed by incineration.
In a typical incinerator,
the waste is burnt in two
consecutive stages. In the first stage, the waste is pyro-
lyzed at 760980C under oxygen-limiting conditions.
This dries the waste and decompose it to volatile gases
and ash. The volatile gases formed in the first stage are
burnt in the second stage at 9801095C with excess air
to achieve complete combustion. The ash produced is dis-
posed in landfills like most municipal solid waste.
For this study, incineration was assumed to result in
complete combustion of waste gloves. Elemental analysis
(CHNS/O analyzer; Thermo ScientificFLASH 2000),
thermogravimetric analysis (TGA/DSC1; Mettler Toledo)
and scanning electron microscopy (Quanta 450 SEM with
Energy Dispersive X-Ray Analysis; FEI) were used to
determine the compositions of all four glove types under
study. Based on the experimentally determined elemental
compositions, the assumption of complete combustion
and stoichiometric considerations,
emissions to atmo-
sphere and the ash production were estimated. Ash is
potentially recyclable and recycling reduces its environ-
mental impact.
Therefore, any environmental impact of
disposing ash from glove incineration, was disregarded. In
addition, environmental contributions of the fuel used in
starting up the incinerator were neglected because com-
bustion of rubber gloves is self-sustaining, that is, little or
no fuel is required once combustion begins.
2.4 |Impact assessment
The LCI of all activities for a FU of 100 pieces of gloves
produced in any factory was converted to 18 environmen-
tal impact indicators based on ReCiPe Midpoint
(H) V1.13/World Recipe H (Table 1). This LCI included
contributions from the rubber plantation, production of
the concentrated NR latex (Figure 1) and final disposal of
the used gloves.
To assist decision makers and other users of environ-
mental impact studies, all 18 environmental impact indi-
cators (Table 1) were normalized and combined into a
single score based on weighting factors. Normalization of
the environmental impacts involved the calculation of
the magnitude of a category indicator relative to some
reference information (e.g., the average yearly emission,
or consumption by one individual in a reference area).
The value of each impact indicator was divided by a
corresponding normalization factor to generate a dimen-
sionless number for each of the 18 environmental impact
categories. The resulting set of dimensionless values was
then multiplied by a set of weighting factors. The
weighting factors prioritized impact categories from those
of highest concern to those of lowest concern, as per-
ceived by the people in the geographic region of focus.
Finally, all 18 weighted dimensionless impact values
were aggregated into a single score for a product or a ser-
The following equation was used in calculating
the single score (point, Pt) of a system boundary:
Single score PtðÞ=W1
TABLE 1 Environmental impact indicators, the corresponding
acronyms and units
Impact category Acronym Units
Climate change CC kg CO
Ozone depletion OD kg CFC-11
Terrestrial acidification TA kg SO
Freshwater eutrophication FE kg P eq
Marine eutrophication ME kg N eq
Human toxicity HT kg 1,4-DB eq
Photochemical oxidant
Particulate matter formation PMF kg PM
Terrestrial ecotoxicity TET kg 1,4-DB eq
Freshwater ecotoxicity FET kg 1,4-DB eq
Marine ecotoxicity MET kg 1,4-DB eq
Ionizing radiation IR kBq U
Agricultural land occupation ALO m
Urban land occupation ULO m
Natural land transformation NLT m
Water depletion WD m
Metal depletion MRD kg Fe eq
Fossil depletion FD kg oil eq
Note: Based on ReCiPe Midpoint (H) V1.13/World Recipe H.
Abbreviations: CFC, chlorofluorocarbons; 1,4-DB, 1,4-dichlorobenzene;
NMVCO, non-methane volatile organic compounds; PM
, particulate
matter with diameter < 10 μm.
where V
was the total value of the environmental impact
category icontributed by all activities in a system bound-
ary, F
was the normalization factor for the impact cate-
gory i, and W
was the weighting factor associated with
the impact category i.
In the present work, all computations of environmen-
tal impact category values and normalization were car-
ried out using the SimaPro with ReCiPe
Midpoint (H) V1.13/World Recipe H. Single scores were
determined manually. The weighting factors were from a
2014 survey of the environmental concerns and priorities
of the respondents.
3.1 |Characterization results
A common observation for all four glove types was that
the glove production stage contributed the most (>50%)
to the impact categories CC, OD, FE, ME, HT, POF, TET,
FET, MET, IR, ALO, ULO, NLT, WD, MRD, and FD for
1 FU of gloves produced (Figures 2(A)(D)). Further
investigation revealed (Figure 3) that for most of these
environmental impact categories, fuel production and
use contributed the most (>50%) to the glove types
NR_PF1 and NBR_PF1. Fuel production and use contrib-
uted the most (>50%) also to the glove types NR_PF2 and
NR_PP2, but in fewer impact categories compared to the
glove types NR_PF1 and NBR_PF1. This could be
ascertained simply by counting the number of impact cat-
egories in Figures 3(A)(D) for the different glove types.
These results implied that coal production and burning
contributed a greater environmental impact compared
with the use of natural gas as fuel. As a consequence,
when natural gas was used, the environmental impact
contributions of the other activities were made apparent
through magnification in relative terms. Fuel, or heating
requirements, has been found to contribute the most to
environmental impacts also in other studies of glove pro-
In glove production processes, coal and gas
are used to mainly generate heat for warming liquid
latexes, drying and chlorination.
Production of concentrated latex (i.e., NR and nitrile
latexes) and transportation of materials to the glove fac-
tory also contributed to environmental burdens, but their
FIGURE 2 The total characterization results for production of one functional unit (FU) of gloves, shown as percentage contribution.
Concentrated latexmeans natural rubber (NR) concentrated latex used in making NR gloves (Figures 2(A), (C), (D)), and nitrile latex used
in making nitrile gloves (Figure 2(B)). See Table 1 for explanation of the acronyms shown below the bars. Glove types: Powder-free NR
gloves from Factory 1 (NR_PF1); powder-free nitrile gloves from Factory 1 (NBR_PF1); powder-free NR gloves from Factory 2 (NR_PF2);
powder coated NR gloves from Factory 2 (NR_PP2)
impact was relatively small in the glove production stage
(Figures 2(A)(D)). The environmental impacts of pro-
duction of concentrated NR latex in Figures 2(A), (C),
and (D) were assessed using a gate-to-gate approach.
Thus, these impacts included both activities inside and
outside the factory. The activities outside the factory
(i.e., outside the latex production stage) were those relat-
ing to production of chemicals, water, and energy (fuel
and electricity), but excluding the activities involved in
the production of fresh NR latex. The environmental
impacts of the production of fresh NR latex were sepa-
rately determined using a cradle-to-gate approach,
accounting for all activities involved outside the planta-
tion boundary relating to all materials, water, and energy
that entered the plantation, as well as all activities occur-
ring within the plantation. In contrast to the gate-to-gate
approach used for assessing impacts of production of
concentrated NR latex, the impacts of production of
nitrile latex were determined using a cradle-to-gate
approach. This took into account all activities relating to
materials, water, and energy that went into the latex pro-
duction stage and all activities occurring within the latex
production stage.
A comparison of all 18 impact categories for the four
glove types (Figure 4) revealed that NR_PP2 contributed
the least to nearly all environmental impact categories
except OD, that is, the emissions related to depletion of
3.2 |Single score results
Different individual impact categories often have differ-
ent units (Table 1) and therefore cannot be compared. To
FIGURE 3 The total characterization results, classified by activities within the glove factories per 1 FU of gloves, shown as percentage
contribution. To enable comparison with nitrile rubber (NBR), the environmental impacts for both latexes were evaluated by using a cradle-
to-gate approach. Thus, the environmental impacts of production of the concentrated natural rubber (NR) latex were the sum of the impacts
from the production of fresh NR latex and those of concentrated NR latex. Concentrated latexmeans NR concentrated latex (includes
production of fresh NR latex) for NR gloves (Figures 3(A), (C), (D)), and nitrile latex for nitrile gloves (Figure 3(B)). See Table 1 for
explanation of the acronyms shown below the bars. See caption of Figure 2 for explanation of glove types
simplify comparison of overall impact, the impact cate-
gory results from the previous section were aggregated
into a single score. This score represented the overall
environmental impact of a glove type as perceived by the
survey respondents. This single-score approach allowed
easy identification of the glove type with the least overall
environmental impact and recognition of production
stages with high overall impacts.
The glove type NR_PF1 was found to have the highest
weighted contribution to the overall environmental
impacts, followed by NBR_PF1, NR_PF2, and NR_PP2,
respectively (Figure 5(A)). For all glove types, the glove
production stage had the highest contribution to the
overall environmental impacts (>50%) (Figure 5(A)). This
dominant impact of the production stage for glove types
NR_PF1, NBR_PF1 and NR_PF2 was linked to their fuel
use (production and consumption of fuel; see table in
Figure 5(B)). In contrast, the high impact of the produc-
tion stage of glove type NR_PP2 was linked to the
chemicals used (see table in Figure 5(B)).
3.3 |Effect of substituting coal for
natural gas in Factory 1 on the overall
environmental impact
This study of fuel substitution was conducted to ascertain
the impact of replacing coal with natural gas on an
energy equivalent basis, without any other change to the
glove production technology. Thus, the quantity of Grade
G coal (calorific value = 10,048 kJ/kg
) required by the
production processes was calculated and replaced with a
quantity of natural gas (calorific value = 52,200 kJ/kg)
that provided the same total energy. The recalculation of
single scores revealed that the fuel substitution reduced
the single scores of both NR_PF1 and NBR_PF1 gloves
by more than 50% (Figure 6), bringing them closer to the
levels of environmental impacts of gloves produced in
Factory 2.
3.4 |Comparison of gloves
3.4.1 |NR gloves (NR_PF1) versus NBR
gloves (NBR_PF1)
A comparison of each impact category for NR_PF1 and
NBR_PF1 for the same functional unit (Figure 4) showed
higher values for NR_PF1 in all impact categories except
MRD. In terms of the overall impact, NR_PF1 had higher
weighted contribution to the overall environmental
impacts than NBR_PF1 (Figures 5(A)). Figure 5(B) rev-
ealed higher single scores for chemicals, production and
combustion of fuel, and glove disposal stage for NR_PF1
than NBR_PF1. As both NR_PF1 and NBR_PF1 were
produced by using the same technology and production
process, the greater environmental impact of NR_PF1
was directly related to the different rubber latex types
(i.e., NR and nitrile latexes). A change in latex type from
NR to nitrile, or vice versa, affected the types and quanti-
ties of the chemicals needed for glove production. A LCA
revealed that use of nitrile latex reduced the energy
required for drying the glove and the sulfur required for
vulcanization. Therefore, NBR_PF1 released less sulfur
dioxide (SO
) in the disposal stages than NR_PF1. This
was confirmed by the low contribution of the disposal
stage of NBR_PF1 for the category TA (Table 1), which
was mainly influenced by the atmospheric release of SO
Nitrogen oxides (NO
), ammonia (NH
), and
hydrochloric acid (HCl) also contributed to TA, but less
than SO
The production of nitrile latex was another important
contributor to the total single score of NBR_PF1
(Figure 5(B)). The single score for the nitrile latex pro-
duction was noticeably high compared to the single
scores associated with the production of fresh NR latex
and its concentrated form. As the nitrile latex was pro-
duced from petroleum, its production contributed greatly
to the impact category fossil depletion (FD), and the
residual chemicals from its decomposition could
FIGURE 4 The total
characterization results per one
functional unit (FU) of gloves.
See Table 1 for explanation of
the acronyms shown below the
bars. See caption of Figure 2 for
explanation of glove types
contaminate soil, enhancing its impact in category TA
(Figure 2(B)).
The main contribution of fresh NR latex
to environmental impacts was in category ME (Figures 2
(A), (C), (D)). ME related to eutrophication of marine
environment (i.e., excessive growth of algae and marine
plants) caused by excess inputs of inorganic nutrients
such as nitrates from fertilizers to the marine ecosys-
Eutrophication is linked to leaching of nitrates
from the rubber plantations to rivers and then to the
marine environment. Nitrate is also contributed by the
atmospheric release of NO
from nitrogen fertilizers used,
and the diesel burnt, at the plantation. In the atmo-
sphere, natural processes convert NO
to nitrate which
ultimately rains back to Earth, to upset the nitrogen bal-
ance in water bodies and other ecosystems.
the NO
emissions were on land, SimaPro
accounted for their impact on the marine ecosystem.
3.4.2 |Powder-free NR gloves (NR_PF2)
versus powdered NR gloves (NR_PP2)
Comparisons of equal functional units of NR_PF2 and
NR_PP2 for individual impact categories and the overall
impact showed higher values for NR_PF2 in all impact
categories (Figure 4) and in single scores (Figure 5(B)).
The single scores of production of fresh NR latex and of
concentrated latex were identical for both glove types
because identical technologies applied to latex production
and concentration for both glove types. Thus, the greater
environmental impact of NR_PF2 was directly related to
the additional chlorination and drying processes applied
to NR_PP2 in order to produce NR_PF2, as displayed in
Figure 1. Life-cycle analysis based on the collected data
showed that the chlorination process was the direct cause
of higher single scores of chemicals and the glove
FIGURE 5 Single scores
(millipoint, mPt) for four glove
types, based on production of
1 functional unit (FU) of gloves,
classified by boundaries (A) and
activities (B). Concentrated latex
in the legend of Figure 5(A) means
natural rubber (NR) concentrated
latex (excluding production of fresh
NR latex) for NR gloves, and nitrile
latex for nitrile gloves. Numbers 19
below the vertical bars in Figure 5
(B) denote: (1) production of fresh
NR latex; (2) production of
concentrated latex;
(3) transportation of materials to a
glove factory; (4) chemicals;
(5) packaging; (6) production and
combustion of the fuel used;
(7) electricity; (8) wastewater; and
(9) disposal of waste gloves. The
data under Figure 5(B) are single
scores of each activity for specified
glove types. See caption of Figure 2
for explanation of glove types
disposal stage. The drying process after the chlorination
treatment increased the energy use by a factor of 1.5 and
hence, was the cause of a higher single score related to
the production and combustion of the fuel.
3.4.3 |Comparison of technologies of
powder-free glove production
NR_PF1 and NR_PF2 represented two technologies of
producing powder-free gloves. Their production used dif-
ferent fuels and chemicals. To produce one FU (100 pairs
of gloves), much higher values for NR_PF1 were
observed in all impact categories, except OD emissions
(Figure 4) and in most single scores (table in Figure 5
(B)). This was because the NR_PF1 technology used coal
as a fuel (Figures 2, 3) and more sulfur was used in the
vulcanization step. The significantly higher OD emissions
of NR_PF2, compared to NR_PF1 (Figure 4), were linked
to the use of natural gas in the glove production processes
of NR_PF2 (Figures 2, 3). In addition, the higher sulfur
contained in NR_PF1 led to its higher single score at the
glove disposal stage compared to NR_PF2 (Figure 5(B)).
3.4.4 |Hotspots for each glove type
Comparison of all four glove types by using the single-
score approach revealed certain environmental impact
hotspots for each glove type. These are summarized in
Table 2 for possible use in future mitigation through
redesign of the production processes. Overall, the
production stage was the main contributor to environ-
mental impacts. In keeping with the present study, the
dominant contribution of the production stage to the
environmental impacts of rubber gloves was also reported
by others.
A significant environmental impact of the
chemicals used during the production stage has also been
The type of fuel used had a major influence on envi-
ronmental impacts, with coal contributing to several of the
identified hotspots. As shown in Figure 6, replacing coal
with natural gas had the potential to lower the overall
impact by more than 50%. A fuel change from coal to nat-
ural gas may be easily implemented in existing production
process. Yet, the overall environmental impacts of
NR_PF1 and NBR_PF1 were still higher than NR_PF2
and NR_PP2, with the latter being the lowest among all
four glove types (Figures 5(A) and 6). After fuel substitu-
tion, the replacement of chemicals used in the production
stages of NR_PF1 and NBR_PF1 became the next environ-
mental impact hotspot issue (Table 2), followed by devel-
opment of a lower sulfur formula for NR_PF1 (to reduce
the impact of the disposal stage) and similar improve-
ments to production of nitrile latex for NBR_PF1.
Furthermore, the environmental impact of glove
types NR_PP2 and NR_PF2 can potentially be reduced by
identifying alternative chemicals with lower impacts.
Minimization of natural gas use in the drying process for
NR_PF2 is also important.
The life cycles of NR and nitrile gloves (powdered and
powder-free gloves) produced in two factories in
Thailand were compared using a cradle-to-grave life cycle
analysis approach for identical FU (100 pieces of gloves).
FIGURE 6 Effect of replacing coal with natural gas (NG) in
the glove production stage of powder-free natural rubber
(NR) gloves from Factory 1 (NR_PF1) and powder-free nitrile
gloves from Factory 1 (NBR_PF1), based on production of 1 FU of
gloves. The single scores (millipoint, mPt) of concentrated latex
were determined by using cradle-to-gate approach. Concentrated
latex (cradle-to-gate)means NR concentrated latex (including
fresh NR latex production) for NR gloves, and nitrile latex for
nitrile gloves. See caption of Figure 2 for explanation of glove types
TABLE 2 Summary of top three environmental impact
hotspots for each glove type, based on production of 1 FU of gloves
NR_PF1 Fuel production and combustion > Chemicals >
Glove disposal
NBR_PF1 Fuel production and combustion > Chemicals >
Nitrile latex
NR_PF2 Fuel production and combustion > Chemicals >
NR_PP2 Chemicals > Fuel production and combustion >
Powder-free NR gloves from Factory 1 (NR_PF1); powder-free nitrile gloves
from Factory 1 (NBR_PF1); powder-free NR gloves from Factory 2
(NR_PF2); powder coated NR gloves from Factory 2 (NR_PP2).
In descending order of single scores.
The assessment revealed that with current technologies
of glove production, regardless of whether powdered or
powder-free gloves are produced, the glove production
stage dominated the environmental impacts. At the raw
materials stage, the nitrile latex contributed to the envi-
ronmental impacts more than the NR latex, but at the
production stage nitrile gloves consumed less energy and
less sulfur for vulcanization. This led to a lower overall
environmental impact, or the total single score, of the
nitrile gloves than the NR gloves. Furthermore, a com-
parison of the powder-free NR gloves and powdered NR
gloves showed that the chlorination process with its
requirement of additional drying, energy and chemicals,
increased the overall environmental impact of powder-
free NR gloves. In addition, the glove-production technol-
ogy using coal as fuel was found to contribute more to
the environmental impacts than the technology that used
natural gas. While NR gloves had higher overall environ-
mental impact than nitrile gloves, the difference was rela-
tively small (10%20%). The NR gloves had the benefit of
using renewable resources.
Life cycle environmental impact of a glove is but
one factor that influences customer choice, usually
only if the other key functional attributes of the avail-
able products are equally satisfactory. For gloves, prop-
erties such as puncture and tear resistance,
stretchiness, and barrier properties, are other impor-
tant considerations.
Financial support for research was provided by Thailand
Research Fund (RDG5850025). Financial support for
publication was provided by National Research Council
of Thailand (NRCT).
None to declare.
Thierry Tran
Yusuf Chisti
Nanthiya Hansupalak
[1] homepage, Disposable gloves market
size, share & trends analysis report by material (natural rub-
ber, nitrile, neoprene, polyethylene), by product (powdered,
powder free), by end use (medical, non-medical), and segment
forecasts, 20202027.
[2] homepage Disposable medical
gloves market size, share & COVID-19 impact analysis, by
application (surgical and examination), by material (latex and
synthetic), by category (powdered and powder free) end
user (hospitals & clinics, diagnostic/pathology labs, and
others), and regional forecast 20202027. https://www.
[3] G. Rasin, Different types of gloves: A facility's guide to selecting
the safest one.
[4] E. Yip, P. Cacioli, J. Allergy Clin. Immunol. 2002,110, S3.
[5] S. Prasertkittikul, Y. Chisti, N. Hansupalak, Ind. Eng. Chem.
Res. 2013,52, 11723.
[6] S. Junoi, Y. Chisti, N. Hansupalak, J. Chem. Technol. Bio-
technol. 2015,90, 185.
[7] M. Arunchaiya, N. Hansupalak, V. Somsongkul, Comparison
of examination gloves produced from natural rubber and
nitrile (Grant no. RDG5850025). Final report, Thailand
Research Fund, Bangkok. 2016.
[8] ISO 14040:2006 Environmental managementlife cycle
assessmentprinciples and framework.
[9] R. Luglietti, P. Rosa, S. Terzi, M. Taisch, Procedia CIRP 2016,
40, 202.
[10] G. K. X. Poh, I. M. L. Chew, J. Tan, Chem. Eng. Technol. 2019,
42, 1771.
[11] P. Usubharatana, H. Phungrassami, Appl. Ecol. Environ. Res.
2018,16, 1639.
[12] N. Kuntachaianun, Master of Engineering thesis, Kasetsart Uni-
versity, (Thailand), 2015.
[13] ISO 14044:2006, Environmental management-life cycle
assessment-requirements and guidelines.
[14] H. -J. Althaus, M. Chudacoff, R. Hischier, N. Jungbluth, M.
Osses, A. Primas, Life cycle inventories of chemicals.
Ecoinvent report no. 8, v 2.0, Swiss Center of Life Cycle Inven-
tories, Dübendorf, Switzerland, 2007.
[15] Thai National Life Cycle Inventory Database, Gate-to-gate LCI
of fresh NR latex and concentrated NR latex. National Metal
and Materials Technology Center, Bangkok, 2015.
[16] Industrial Estate Authority of Thailand, Handbook of business
operation in Thailand's industrial estate version 2: Ministerial reg-
ulation control of infectious waste disposal B.E. 2545 (2002),
[17] AP-42, in compilation of air pollutant emission factors volume I:
Stationary point and area sources, Office of Air Quality Planning
and Standards, U.S. Environmental Protection Agency, 1995.
[18] W. R. Niessen, Combustion and Incineration Processes: Appli-
cations in Environmental Engineering, CRC Press, Boca Raton,
FL 2010.
[19] M. Margallo, R. Aldaco,
A. Irabien, Clean Technol. Environ.
2014,16, 1319.
[20] T. M. Mettier, P. Hofstetter, J. Ind. Ecol. 2004,8, 189. http://dx.
[21] R. Andreas, S. Serenella, N. Jungbluth, Int. J. Life Cycle
Assess. 2020,25, 1859.
[22] A. K. Shaha, Combustion Engineering and Fuel Technology:
Optimum Utilization of Fuels, Oxford & IBH, New Delhi 1974.
[23] F. Verones, S. Hellweg, A. Antón, L. B. Azevedo, A.
Chaudhary, N. Cosme, S. Cucurachi, L. D. Baan, Y. Dong, P.
Fantke, L. Golsteijn, M. Hauschild, R. Heijungs, O. Jolliet, R.
Juraske, H. Larsen, A. Laurent, C. L. Mutel, M. Margni, M.
Núñez, M. Owsianiak, S. Pfister, T. Ponsioen, P. Preiss, R. K.
Rosenbaum, P.-O. Roy, S. Sala, Z. Steinmann, R. V. Zelm,
R. V. Dingenen, M. Vieira, M. A. J. Huijbregts, J. Ind. Ecol.
2020,24, 1201.
[24] H.-R. Kerstin, M. Simon, J. Soils Sediments 2005,5, 59. http://
[25] C. Jessen, V. N. Bednarz, L. Rix, M. Teichberg, C. Wild, in
Environmental Indicators (Eds: R. H. Armon, O. Hänninen),
Springer, Dordrecht 2015.
[26] A. Miola, V. Paccagnan, I. Mannino, A. Massarutto, A. Perujo
Mateos del Parque, M. Turvani, External costs of
transportation case study: Maritime transport. Publication
EUR 23837 EN. European Commission, Ispra, Italy, 2009.
How to cite this article: Patrawoot S, Tran T,
Arunchaiya M, Somsongkul V, Chisti Y,
Hansupalak N. Environmental impacts of
examination gloves made of natural rubber and
nitrile rubber, identified by life-cycle assessment.
SPE Polymers. 2021;2:179190.
... A recently published database aggregates LCAs relating to healthcare products and processes [12]. Some LCAs accessible in the database, such as those on disposable personal protective equipment (PPE) and nitrile gloves, are transferable to laboratories [13][14][15][16]. However, LCAs on common singleuse lab plastics do not yet exist. ...
Full-text available
Scientific research pushes forward the boundaries of human knowledge, but often at a sizable environmental cost. The reliance of researchers on single-use plastics and disposable consumables has come under increased scrutiny as decarbonisation and environmental sustainability have become a growing priority. However, there has been very little exploration of the contribution of laboratory consumables to ‘greenhouse gas’ (GHG) carbon emissions. Carbon footprint exercises, if capturing consumables at all, typically rely on analyses of inventory spend which broadly aggregate plastic and chemical products, providing inaccurate data and thus limited insight as to how changes to procurement can reduce emissions. This paper documents the first effort to quantify the carbon footprint of common, single-use lab consumables through emission factors derived from life cycle assessments (LCAs). A literature review of LCAs was conducted to develop emission factors for lab consumables, considering the emission hotspots along each product’s life cycle to identify where emission reduction policies can be most effective. Results can be used as inputs for lab practitioners seeking to understand and mitigate their carbon footprint.
... With the increased interest in sustainable materials, natural rubber research has resurfaced as a research topic around the world, from stabilization techniques, [36] such as presented here, to life cycle analyses that show the how natural rubber products rise above any synthetic materials that it replaces. [37] In this paper, we presented two novel liquid latex preservation and stabilization methods in an acid medium free of ammonia or other dangerous chemicals. We predict that this novel, counterintuitive method, of preservation of liquid natural rubber latex, in an acidic environment, will prove to be transformative in the natural rubber industry. ...
Full-text available
Abstract Natural rubber is an indispensable raw material that supplies about half of the world's rubber consumption. The latex that is extracted from the trees is composed of polyisoprene rubber, proteins, sugars, amino acids, lipids, and minerals. When the liquid latex emanates from the trees, it comes into contact with bacteria that cause it to decompose and coagulate. To hinder the decomposition and destabilization process, ammonia and other environmental and health hazard chemicals are added to the latex. The addition of these chemicals affects the health of plantation and rubber industry workers and results in residues that are contaminated with these chemicals, which require that processing facility effluents undergo costly treatment processes. Here, we present two novel liquid latex preservation and stabilization methods in an acid medium free of ammonia or other dangerous chemicals. The first method uses dodecyl benzene sulfonic acid to both stabilise and preserve the liquid latex, and the second uses ethoxylated tridecyl alcohol to stabilise and hydrofluoric acid to preserve the colloidal suspension. Both formulations result in rubber with superior mechanical properties, that is safe for the rubber plantation and industry workers, and with residues that no longer adversely affect the environment.
... The most commonly used gloves are nitrile, latex, and vinyl gloves (Fig. 2f). Nitrile gloves are made of synthetic material nitrile butadiene rubber (NBR) [37]. These gloves have high chemical resistivity and are best for preventing allergies. ...
Earth's plastic pollution has increased due to the COVID-19 pandemic, and the world is on the doorstep of an enormous waste pandemic. The extensive use of mandatory personal protectives like masks, gloves, and PPE kits and the lack of proper waste management systems lead to a rise in the plastic pollution content of the earth. Such disposable and non-biodegradable personal protectives are thrown out to the environment after use. These distributed wastes pollute land, soil, and water bodies and effects their ecosystems. This research work establishes the concept of a waste-to-energy conversion approach to reuse COVID-19 scraps for green and sustainable development. Three-layered surgical masks and nitrile gloves were reused in this work after sterilization for energy harvesting and sensing applications by fabricating a 3D-printed contact-separation-based triboelectric nanogenerator. A piece of three-layered mask and nitrile gloves were placed inside the 3D structure as the top negative and bottom positive triboelectric materials with copper and aluminum as corresponding electrodes (MG-CS TENG). It can convert external mechanical motions into electrical energy. The maximum voltage, current, and power density obtained from the device are 50.7 V, 4.8 µA, and 6.39 µW/cm2, respectively, for a mechanical force of 9 N. The harvested energy was sufficient to power small-scale electronic devices like digital tally counters, wristwatches, lumex displays, and series connected 25 LEDs. MG-CS TENG was also performed as a pedal-operated touch sensor to dispense hand sanitizer. MG-CS TENG was pedal pressed to trigger a microcontroller and control the solenoid valve's opening and closing to regulate sanitizer flow. The setup was integrated using the internet of things (IoT) and Blynk cloud services for the remote monitoring and controlling of the sanitizer dispenser using a smartphone. This work contributes a substantial role in disaster management to suppress microplastic environmental pollution by reusing pandemic wastes for energy harvesting and sensing applications and preventing the spread of coronavirus through proper hand sanitization.
... Intensive effort is being made to enhance the sustainability and reduce the environmental impact of production of natural rubber gloves [15][16][17]. To minimize environmental impact, the present work used UV-prevulcanization with a diacrylate agent to prepare prevulcanized natural rubber (PVNR) films composited with purified multiwalled carbon nanotubes (MWCNT) as the conductive filler. ...
... 141 Furthermore, the environmental impact of gloves can be reduced by using powder coating gloves rather than chlorination to reduce stickiness. 142 In addition, cohorting of COVID-19-positive patients in dedicated endoscopy lists may also minimise PPErelated waste. 4 Where single-use PPE cannot be reduced, several studies have suggested recycling as a way of tackling the mass amount of single-use plastic waste generated. ...
Full-text available
GI endoscopy is highly resource-intensive with a significant contribution to greenhouse gas (GHG) emissions and waste generation. Sustainable endoscopy in the context of climate change is now the focus of mainstream discussions between endoscopy providers, units and professional societies. In addition to broader global challenges, there are some specific measures relevant to endoscopy units and their practices, which could significantly reduce environmental impact. Awareness of these issues and guidance on practical interventions to mitigate the carbon footprint of GI endoscopy are lacking. In this consensus, we discuss practical measures to reduce the impact of endoscopy on the environment applicable to endoscopy units and practitioners. Adoption of these measures will facilitate and promote new practices and the evolution of a more sustainable specialty.
... The global demand for nitrile gloves is estimated to increase at a compound annual rate of 10.6%-11.2% until 2027 (Patrawoot et al., 2021). In 2021, it was predicted that the market size for nitrile gloves would be worth about 8.76 billion USD. ...
The COVID-19 pandemic not only poses an unprecedented threat to global health but also severely disrupts the natural environment and ecosystems. Mitigating the adverse impacts of plastic-based personal protective equipment (PPE) waste requires the cooperation of professionals from various fields. This paper discusses a novel, cleaner approach to soil stabilisation by repurposing the nitrile gloves into a sustainable road material to improve the mechanical properties of expansive clay soil as pavement subgrade. For the first time, extensive geotechnical testings, including standard compaction, unconfined compressive strength (UCS), unsoaked California bearing ratio (CBR), repeated load triaxial (RLT), and swelling-shrinkage tests, were carried out to investigate the engineering performance of different proportions of the shredded nitrile gloves (SNG) (e.g., 1%, 1.5%, 2%) were blended with expansive clay (EC). In addition, surface roughness, scanning electron microscopy (SEM), and X-ray micro-CT analyses were conducted, and images were obtained to study the microstructural modification of the EC-SNG mixtures. The experimental results indicated that the blend of expansive clay with SNG helped in increasing the compressive strength, resilient modulus, and CBR and assisted in reducing the swelling and shrinkage of the soil. SEM and surface roughness analyses indicated the interaction between the soil matrix interface and the rough surface of the SNG. The main reasons for increasing the strength and stability of clay soil could be attributed to the high tensile strength of the SNG and the formation of the three-dimensional grid, and friction between the soil particles and SNG. According to the X-ray micro-CT test results, the incorporation of SNG led to an increase in closed porosity.
Glove-based wearable chemical sensors are universal analytical tools that provide surface analysis for various samples in dry or liquid form by swiping glove sensors on the sample surface. They are useful in crime scene investigation, airport security, and disease control for detecting illicit drugs, hazardous chemicals, flammables, and pathogens on various surfaces, such as foods and furniture. It overcomes the inability of most portable sensors to monitor solid samples. It outperforms most wearable sensors (e.g., contact lenses and mouthguard sensors) for healthcare monitoring by providing comfort that does not interfere with daily activities and reducing the risk of infection or other adverse health effects caused by prolonged usage. Detailed information is provided regarding the challenges and selection criteria for the desired glove materials and conducting nanomaterials for developing glove-based wearable sensors. Focusing on nanomaterials, various transducer modification techniques for various real-world applications are discussed. The steps taken by each study platform to address the existing issues are revealed, as are their benefits and drawbacks. The Sustainable Development Goals (SDGs) and strategies for properly disposing of used glove-based wearable sensors are critically evaluated. A glance at all the provided tables provides insight into the features of each glove-based wearable sensor and enables a quick comparison of their functionalities.
Since the COVID-19 outbreak in late 2019, a surprisingly large amount of personal protective equipment, such as medical rubber gloves, have been frequently used, and this medical waste can cause very major environmental problems. A multidisciplinary collaborative approach is needed to combat the pandemic and lessen the environmental risks associated with the disposal of medical waste. This study developed an innovative approach by incorporating shredded rubber glove fibers (RGF) into aggregates to enhance the fatigue resistance of concrete. In this study, different volume contents (0.5%, 1.0%, 1.5%, 2.0%) of RGF were added to the aggregate for the first time. The effects of different RGF contents on the fatigue characteristics of concrete were examined through repeated loading tests and SEM analysis. The results show that the width and number of cracks produced by rubber glove fiber concrete (RGFC) after repeated loading are significantly reduced compared with normal concrete (NC). Following repeated loading, RGFC exhibited higher total, plastic, and elastic strain values than NC, demonstrating greater deformability and elasticity. However, the maximum total strain growth rate and the total strain growth range of the RGFC group were only 2.26 × 10⁻³/time and 14.0%, which were significantly smaller than the 3.8 × 10⁻³/time and 31.7% of the NC group, showing better stability, corresponding to enhance the fatigue resistance of concrete. The interfacial transition zone (ITZ) was abnormally smooth with a thin thickness and no visible gaps were discovered, based on the results of SEM test performed on the RGFC. The findings obtained in this study may provide new ideas for the resource utilization of medical waste.
The thermocatalytic co-pyrolysis of pine wood and plastics (waste nitrile gloves (WNG) and polystyrene (PS)) into renewable liquid fuel was the focus of the current study. The pyrolysis test is executed in a semi-batch reactor at 600 °C, 80 °C min⁻¹ heating rate, and 100 mL min⁻¹ nitrogen flow rate. The waste plastics and MgO were mixed with PW at 10, 20, and 30 wt% loadings, respectively. The proximate, ultimate, HHV, bulk density, biochemical, extractive, TGA, FTIR, viscosity, density, acidity, and GC-MS methods were used to characterize the raw feeds and pyrolytic oil. The physicochemical analysis of raw feeds confirmed their suitability for use as pyrolysis feedstock. The maximum yield of co-pyrolytic oil is found to be 46.76 and 45.41 wt% for PW + WNG and PS, at 20 wt% however, 48.12 and 48.76 wt% is found to be at PW + PS (20 wt%)+MgO (20 wt%) and PW + WNG (20 wt%)+MgO (20 wt%) respectively. The characterization results of pyrolytic oil validated that co-pyrolytic oil provides an improved yield than the individual pyrolysis of raw feeds. In thermocatalytic co-pyrolytic oil, it was discovered that the viscosity, oxygen content, and moisture had all decreased, whereas the heating value, density, carbon content, and acidity had all significantly increased. FTIR examination of pyrolytic oil established the appearance of aromatics hydrocarbon and oxygenated products, whereas GC-MS results validated a substantial reduction in oxygenated components and an increased hydrocarbon percentage at 20 wt% mixing of waste plastics and catalyst.
Full-text available
Life cycle impact assessment (LCIA) is a lively field of research, and data and models are continuously improved in terms of impact pathways covered, reliability, and spatial detail. However, many of these advancements are scattered throughout the scientific literature, making it difficult for practitioners to apply the new models. Here, we present the LC‐IMPACT method that provides characterization factors at the damage level for 11 impact categories related to three areas of protection (human health, ecosystem quality, natural resources). Human health damage is quantified as disability adjusted life years, damage to ecosystem quality as global species extinction equivalents (based on potentially disappeared fraction of species), and damage to mineral resources as kilogram of extra ore extracted. Seven of the impact categories include spatial differentiation at various levels of spatial scale. The influence of value choices related to the time horizon and the level of scientific evidence of the impacts considered is quantified with four distinct sets of characterization factors. We demonstrate the applicability of the proposed method with an illustrative life cycle assessment example of different fuel options in Europe (petrol or biofuel). Differences between generic and regionalized impacts vary up to two orders of magnitude for some of the selected impact categories, highlighting the importance of spatial detail in LCIA.
Full-text available
Production of synthetic gloves may cause adverse environmental impacts, including global warming, carbon footprint, acidification, photochemical ozone formation, eutrophication, human toxicity and water footprint. Thus, life cycle assessment is used as an environmental management tool to evaluate its environmental impacts. Life cycle optimization is implemented to minimize energy consumption and greenhouse gases emission by proposing five alternative process improvement scenarios. Using electricity generated from biodiesel (Alt. III) shows the least environmental impacts as compared to the other alternatives for the production of synthetic glove. Future, economic analysis is needed to study the cost feasibility of these alternatives.
Conference Paper
Full-text available
In recent years, sustainable development has acquired a relevant position in our society. In this context, the design of modern products must consider these issues when creating eco-friendly and socially acceptable solutions, seeing sustainability as a matter of optimization in the use of available resources along the entire product lifecycle. This research aims to propose a dedicated Environmental Assessment Framework, using LCA methodology allowing designers to make environmental sustainability as an achievable and measurable requirement for developing new products. The case study presented is adapting the Life Cycle Assessment framework in the household refrigerator sector, of comparison between conventional gas-compression refrigeration and magnetic cooling system. The critical point of magnetic refrigerator is the presence of rare earths, and for this reasons a Life Cycle Assessment toll is needed to investigate the whole lifecycle.
Full-text available
Eutrophication is one of the key local stressors for coastal marine ecosystems, particularly in those locations with many estuaries, intense coastal development or agriculture, and a lack of coastal forests or mangroves. The land-derived import of not only inorganic nutrients, such as nitrate and phosphate, but also particulate and dissolved organic matter (POM and DOM) affects the physi-ology and growth of marine organisms with ensuing effects on pelagic and benthic community structures, as well as cascading effects on ecosystem functioning. Indicators for marine eutrophication are therefore not only key water quality parameters (inorganic and organic nutrient concentrations, oxygen and chlorophyll availability, and biological oxygen demand), but also benthic status and process parameters, such as relative cover and growth rates of indicator algae, invertebrate recruitment, sedimentary oxygen demand, and interactions between indicator organisms. The primary future challenge lies in understanding the interaction between marine eutrophication and the two main marine consequences of climate change, ocean warming, and acidification. Management action should focus on increasing the efficiency of nutrient usage in industry and agriculture, while at the same time minimizing the input of nutrients into marine ecosystems in order to mitigate the negative effects of eutrophication on the marine realm.
Full-text available
Conventional bottom ash (BA) management consists of a solidification process using inorganic binder reagents, such as cement. However, despite the heavy metal content, the use of BA as a natural aggregate has become increasingly more common. In particular, bottom ash is used as a raw material for clinker, cement mortar or frit production, as a drainage layer in landfills or as a sub-base material in road construction. In this study, the life cycle assessment approach was used to evaluate and compare ash solidification with ash recycling in Portland cement production as a clinker and gypsum substitute. The findings showed that the substitution of ash for clinker resulted in the lowest natural resources (NR) consumption and the lowest environmental burdens (EB). The decrease in the clinker substitution percentage generated a higher NR consumption and an increased EB. In ash recycling, the distance between the incinerator and the cement facility is an important parameter in the decision-making process. Specifically, ash solidification presented less favourable results than ash recycling (with a clinker substitution of 25 %), despite the increasing distance between the incinerator and the cement facility. However, when the clinker substitution decreased to 2.5 % or when ash was substituted for gypsum, the distance played an important role in the water impact.
Carbon footprint emissions related to the natural latex supply chain including farm cultivation, concentrated latex production and rubber glove processing were investigated. Data were collected from 656 rubber plantations covering six provinces in the northeast, east, and south of Thailand and three concentrated latex production plants including one rubber glove processing factory. Different allocation methods were considered to compare the carbon footprint results including mass allocation, economic allocation and allocation by dry rubber content (DRC). Calculation methods were based on life cycle assessment (LCA) and ISO14067. Results indicated that farm size had no impact on the carbon footprint of fresh latex, with the carbon footprint of fertilizer application at planting estimated at more than 90% of the total contribution. For concentrated latex production, almost 70% of the carbon footprint originates from rubber cultivation. Total carbon footprint emission of 200 pieces of rubber glove was about 42 kg CO2-eq, allocated by mass during cultivation and by DRC in concentrated latex processing, with less than 1% from rubber plantations and concentrated latex processing. Allocation methods for the carbon footprint of rubber gloves do not affect the final result but have a great impact on the upstream process.
Deproteinization of natural rubber using an alkaline protease from Bacillus sp. immobilized on cross-linked chitosan beads is reported. Conditions were identified for attaining a high activity of the immobilized enzyme on the beads. The optimally produced enzyme beads were then used to establish the conditions for effective deproteinization of natural rubber. A two-level full factorial design was used to quantify the main effects and the interaction of the factors influencing the formation of the catalytic beads and the rubber deproteinization process. Results showed that by using the optimal deproteinization process, the total nitrogen level in the rubber was reduced from 0.35% to 0.013% w/w, or a >96% nitrogen removal. In contrast, the urea method of deproteinization achieved a lower nitrogen removal of <86%.The immobilized protease could be used for at least five repeated deproteinization cycles without losing more than 10% of the initial enzyme activity.
Background Natural rubber latex contains allergenic proteins. Therefore, processes for deproteinizing the latex are needed. An immobilized enzyme process for deproteinization is reported. An optimal protocol was first developed for immobilizing a protease on cellulose−chitosan composite beads. The beads were then used in developing an optimal deproteinization treatment. The main effects and the interactions of the factors for the two processes were identified using a two-level full factorial experimental design. ResultsUnder optimal conditions (15% cellulose in beads, immobilizing reaction pH of 9, immobilization period of 24 h), the beads attained the highest specific activity of 1,685 U/g. Using these beads, the optimal conditions for deproteinization of the latex were: an enzyme loading of 0.1 parts per hundred of rubber (phr), a sodium dodecyl sulfate concentration of 20 phr, 30 °C, and a treatment period of 12 h. The nitrogen content of the rubber was reduced to 0.012% from an initial value of 0.3%. The enzyme beads were operationally stable and could be reused for at least five cycles. Conclusions The optimized treatment effectively deproteinized the natural rubber. The final product was free of peptides. This deproteinization treatment was more effective than the conventional urea-based treatment performed for comparison.