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Life cycle assessment of paper towel and electric dryer as hand drying method in the University of Melbourne

January 2007
Teknik 28(2)

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University of York

Nowadays products, services, or technologies are proactively evaluated toward environmental performance byusing the life cycle assessment (LCA). The assessment cover the whole life cycle from cradle to grave hence theproduct performance can be analyzed or compared with others for product development or for making adecision. The University of Melbourne currently installed towel dispenser by means of hand drying method inthe entire campus. As some has suggested that electric dryer will provide more sustainable service than papertowel, a LCA study will be a good approach for comparing both methods. The study utilizes SimaPro softwareto generated database for impact assessment. The assessment method used in this study is Eco-Indicator 99.From the LCA study, electric hand dryer performed better in most of indicators. Electric hand dryer istherefore recommended to be used in the entire campus of the University of Melbourne

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TEKNIK – Vol. 28 No. 2 Tahun 2007, ISSN 0852-1697

132

*) Staf Pengajar Jurusan Teknik Lingkungan Fakultas

Teknik Universitas Diponegoro

LIFE CYCLE ASSESSMENT OF PAPER TOWEL AND ELECTRIC

DRYER AS HAND DRYING METHOD IN THE UNIVERSITY OF MELBOURNE

Sri Hapsari Budisulistiorini *)

Abstract

Nowadays products, services, or technologies are proactively evaluated toward environmental performance by

using the life cycle assessment (LCA). The assessment cover the whole life cycle from cradle to grave hence the

product performance can be analyzed or compared with others for product development or for making a

decision. The University of Melbourne currently installed towel dispenser by means of hand drying method in

the entire campus. As some has suggested that electric dryer will provide more sustainable service than paper

towel, a LCA study will be a good approach for comparing both methods. The study utilizes SimaPro software

to generated database for impact assessment. The assessment method used in this study is Eco-Indicator 99.

From the LCA study, electric hand dryer performed better in most of indicators. Electric hand dryer is

therefore recommended to be used in the entire campus of the University of Melbourne.

Keywords: life cycle assessment, paper towel, electric dryer, SimaPro, Eco-Indicator 99

Introduction

There are some methods of hand drying including paper

towel, cloth towel, electric hand dryer, and spontaneous

evaporation. Two of these methods, paper towel and

electric hand dryer, are commonly used in buildings such

as office, commercial, and institution. Some people

argue that paper towel can dry hands more efficient,

quicker and also can function as cleaner media than hot

air dryer (Blackmore, 1987; Knights, Evans, Barrass, &

McHardy, 1993). Suspension of bacteria persists on wet

hands but not on well-dried ones (Coates, Hutchinson, &

Bolton, 1987) while hot air dryer can spread pathogenic

bacteria onto hands and body, as well as inhaled and

distributed across the room (Redway, Knights, Bozoky,

Theobald, & Hardcastle, 1994). Others, on the other

hand, claim that hot air dyer has less environmental

impacts due to less emission and resource depletion

(ERM, 2001) and having no significant difference on

spreading bacteria compared to paper towel (Matthews &

Newsom, 1987; Meers & Leong, 1989; Redway et al.,

1994). Therefore a life cycle assessment of hand drying

methods is necessary to reveal performance of both

methods towards environment.

Life cycle assessment (LCA) is a study of a product’s

environmental impacts throughout its life cycle; from the

extraction of raw material, production process, use, until

its disposal into landfill (Hendrickson et al., 2006; PRE,

2006a). The LCA study comprises four stages, goal and

scope, inventory, impact assessment, and interpretation.

Goal and Scope of The Life Cycle Assessment (LCA)

Goal and scope

The LCA study aims to compare the environmental

performance of two methods of hand drying in the Uni-

versity of Melbourne, Parkville campus. The methods

include:

1. Paper towel. Recently, the university installed paper

towel dispenser in most toilets in the entire campus.

2. The proposed system is using electric hand dryer.

Some people suggested that electric dryer is a better

method of removing water than paper towel.

The functional unit is number of dries. It is assumed a

130,000 of dries for both methods.

System boundaries

This study will assess life cycle of hand drying methods

of paper towel and electric hand dryer. Production

process of both methods are assumed and simulated in

SimaPro software. The systems of the two methods are

illustrated in Figure 1 and 2. The system boundaries

include raw material and disposal scenario which are

larger than the point of use, the university. It is important

to include those scenarios since point of use assessment

will insufficient to reveal the real impacts of products or

services. As can be seen from the flow diagram of both

products, point of use comprise the smallest part of the

life cycle. Thus involving all processes from cradle to

grave to evaluate products sustainability towards envir-

onment are necessary.

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Figure 1 System boundary of paper towel

Figure 2 System boundary of electric hand dryer

Description of system

Paper Towel

A system of paper towel for hand drying method

comprises paper towel, towel dispenser, and rubbish

bin. It is assumed that a folded-paper towel has an

average weight of 3.9 gram (ERM, 2001). Dispenser

and bin are included in the SimaPro model as additional

life cycle to paper towel LCA. The amount of paper

required are 260,000 sheets with assumptions of 2

sheets of paper per use amounting to 1,040 kg of paper

towel. The system is capable to provide 70 drying each

day for the same lifetime with electric hand dryer.

Electric Hand Dryer

Electric hand dryer is assumed to have 5 years of

lifetime which will require 1,083 kWh or 3.9 GJ for 30

seconds of average use. The electricity is supplied from

coal-fired power plant through national grid and

renewable resources. The renewables comprise 10% of

energy used in University of Melbourne.

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Life Cycle Inventory (LCI)

Data required for this study is mainly from SimaPro

database. Since the databases are referred to European

countries, the study is aimed to get the closest approach

to the case in Australia. The demo version of software

has some limitations, thus some data are presumed

from previous report and web sources. Assumptions

used in the data generation are contained in table 1. The

assessment is based on some approaches. For paper

towel, recycling paper is selected as the raw material

which production mainly contributes to the life cycle of

paper towel. In case of electric dryer, cast iron is

chosen for raw material of casing.

Table 1 Assumptions made for LCA paper towel versus electric hand dryer

Description Unit Value

Number of drier 130,000

Lifetime years 5

seconds 30

hours 1,083

kWh 1,083

GJ 3.9

Electricity from renewables GJ 0.4

Electricity from coal GJ 3.5

Phys ical properties

Body: cast iron kg 7

Components:

a. Push button, wires: chromium kg 0.1

b. Motor: copper kg 1

Paper required sheets /dry 2

Paper us ed sheets 260,000

Paper weight g 4

Total weight kg 1,040

Drying capacity dries/day 71

Ratio of paper recovery 1.0

Used paper required kg 1,040

Paper Towel

Electricity used

Time of drying

Electric Hand Dryer

Source: calculation and some assumptions (AmericanDryer, 2006; ERM, 2001)

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Figure 3 Flow diagram of paper towel life cycle

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Figure 4 Flow diagram of electric hand dryer life cycle

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Table 2 Inventory of life cycle of paper towel and electric dryer

No Substance Compartme

Unit Life Cycle paper towel Life Cycle

hand dryer

1 Carbon dioxide Air kg 428.28680 973.90303

2 Heat, waste Air MJ 0.00000 6,470.74265

3 Methane Air kg 0.73365 3.55074

4 Nitrogen oxides Air kg 3.01137 0.93386

5NMVOC, non-methane volatile organic

compounds, unspecified origin Air kg 1.04046 0.13380

6 Particulates Air kg 0.81159 0.00008

7 Radioactive species, unspecified Air Bq 1,231,234,464.21077 3,481.37445

8 Sulfur oxides Air kg 3.86772 1.16828

9 Carbon Soil kg 1.56156 0.00243

10 Heat, waste Soil MJ 0.00000 1.21402

11 Nitrogen, total Soil kg 0.11864 0.00000

12 Chloride Water kg 22.29303 7.53015

13 BOD5, Biological Oxygen Demand Water kg 1.65287 0.00060

14 COD, Chemical Oxygen Demand Water kg 8.45854 0.00653

15 Heat, waste Water MJ 0.00000 835.80645

16 Lead Water kg 0.00069 0.00556

17 Nitrate Water kg 5.60461 0.02509

18 Phosphate Water kg 0.03814 0.06547

19 Radioactive species, unspecified Water Bq 11,388,397.66942 33.29128

20 Sulfate Water kg 11.74875 4.82549

21 Suspended substances, unspecified Water kg 4.24470 0.00016

22 TOC, Total Organic Carbon Water kg 5.28618 0.00000

23 Waste water/m3 Water m3 47.04960 0.00000

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Life Cycle Impact Assessment (LCIA)

Impact assessment of hand drying methods is using

Eco-Indicator 99. It approaches the result at the end po-

int or damage oriented approach which evaluates the

damage caused by product onto three indicators, human

health, ecosystem, and natural resource. The damage is

weighted according to sustainability indicators (Dewulf

& Langenhove, 2006; PRE, 2006b). Table 3 presents

the impact burdens from using paper towel and electric

dryer based on Eco-Indicator 99. There are 11

categories from three types of damage. Damage to

human health is represented with Disability Adjusted

Life Years (DALY) while damage to ecosystem quality

is expressed with Potentially Disappeared Fraction

(PDF). Mega Joule (MJ) surplus is expressing addi-

tional energy required to extract low quality of mineral

and fossil due to resources damage.

Table 3 Damage assessment of comparison of paper towel and electric dryer

by using Eco-Indicator 99 method

Impact category Unit Life Cycle paper

towel

Life Cycle hand

dryer

Carcinogens DALY 0.00003 0.00015

Resp. organics DALY 0.00000 0.00000

Resp. inorganics DALY 0.00058 0.00019

Climate change DALY 0.00009 0.00022

Radiation DALY 0.00000 0.00000

Ozone layer DALY 0.00000 0.00000

Ecotoxicity PDF*m2yr 7.79855 6.95432

Acidification/ Eutrophication PDF*m2yr 23.01591 6.64641

Land use PDF*m2yr 0.00000 6.45559

Minerals MJ surplus 1.50593 17.87221

Fossil fuels MJ surplus 704.41664 223.41701

Interpretation

Paper towel impact toward environment sus-tainability

outperformed electric dryer by six to five of indicators.

The sustainability indicators and the environmental

impact of paper towel and electric dryer to environment

are presented in below. The impacts assessment has

limitation as they were generated from European da-

tabases. This limitation is acknowledged to be a barrier

for using SimaPro as methodological approach.

Environment impact

Environment effect is assessed based on damage to

ecosystem quality which is represented in ecotoxicity,

acidification/eutrophication, and land use categories. In

land use which is claimed as the most potential impact

category (Dewulf & Langenhove, 2006), electric dryer

was outperformed by paper towel. Extraction of

material for hand dryer assembly requires land clearing

which directly threatens local and global ecosystems.

Although land use plays significant role the ecotoxicity

and acidification /eutrophication should be considered

to increase environmental burdens. Paper towel method

emits greenhouse gasses relatively higher than hand

dryer (Table 5). Emission of sulfur oxides from the life

cycle of paper towel is high and causing acid rain

(acidification). Water pollu-tion from wastewater stre-

am of paper towel life cycle is higher than hand dryer,

especially on BOD, COD, TOC, sulfate, chloride,

nitrate, and suspended solid contents (Table 2).

Table 4 Comparison of greenhouse gases emission from paper towel and electric dryer

No Substance Compartme

nt Unit Life Cycle

paper towel

Life Cycle

hand dryer GWP

Paper Towel

Hand dryer

1 Carbon dioxide Air kg 428.28680 973.90303 1 428.28680 973.90303

2 Methane Air kg 0.73365 3.55074 21 15.40667 74.56550

3 Nitrogen oxides Air kg 3.01137 0.93386 310 933.52610 289.49744

Total 1377.21957 1337.96597

GHG emissions (kg of CO2-eq)

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OCIAL IMPACT

Human health indicator represents social impact of

hand drying methods to user and community. Hand dr-

yer surpassed paper towel in this indicator, particularly

on significant effect from inorganic substances to

respiratory (Dewulf & Langenhove, 2006). Paper towel

made from recycling paper which process requires

addi-tional substances to improve quality. Moreover,

paper towel is not free from contamination of

microorganism although it is stored in a dispenser.

Used paper might contain bacteria and might spread

disease through air circu-lation. In addition, paper

towel method is labour intensive and is affected by

users’ behaviour. Cleaning rubbish bin could be unsafe

for em-ployee when used and wet papers are scattered

on the floor. On the other hand, utilizing hand dryer

needs less maintenance and can provide complete

dryness.

Figure 5 Using Eco-Indicator 99 to indicate sustainability indicator and to compare environmental sustainability of paper

towel and electric dryer

Table 5 Single score of comparison of paper towel and electric dryer using Eco-Indicator 99

Impact category Unit Life Cycle paper

towel Life Cycle hand dryer

Total Pt 37.61694 22.07429

Carcinogens Pt 0.87837 3.94424

Resp. organics Pt 0.03817 0.00670

Resp. inorganics Pt 15.03315 5.03769

Climate change Pt 2.45582 5.74911

Radiation Pt 0.00000 0.02768

Ozone layer Pt 0.00696 0.00179

Ecotoxicity Pt 0.60829 0.54244

Acidification/ Eutrophication Pt 1.79524 0.51842

Land use Pt 0.00000 0.50354

Minerals Pt 0.03584 0.42536

Fossil fuels Pt 16.76512 5.31732

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Figure 6 Using Eco-Indicator 99 to compare environmental sustainability performance of paper towel and electric dryer

in a single score

Economic impact

Main economic impact from using paper towel is

increasing effort on extracting fossil fuels. Paper towel

method requires massive transport due to its bulkiness.

Furthermore recycling process of paper follows the

similar pattern as the new one, except less virgin

material input. Therefore recycling paper uses higher

energy for production.

The analysis from software was calculating economic

impact throughout the life cycle hen-ce it did not

distinguish the impact to the university. To approach

more realistic result of economic burden from those

methods, simple financial cost was calculated. Using

paper towel will be costly than using electric dryer.

Electricity for hand dryer throughout its life cycle costs

for only A$ 152 compared to A$ 15,600 of paper towel

cost. The comparison is using the similar functional

unit used in the LCA study (Table 5 and 6). Cost of

using hand dryer might be cheaper as the price of

electricity in Australia is low vis-à-vis global prices

(UIC, 2006). Moreover the high cost of using paper

towel is attributed to the efficiency of drying. At least 2

sheets of paper are needed to drying hands and the

price of a paper towel is expen-sive, 6 cent per sheet of

paper towel compared to 14 cent per kWh of electricity

for 120 of drying times.

Overall assessment is represent by single score where

paper towel impacts toward all categories exceeded

electric dryer. In total, impacts from utilizing paper

towel are accounting for 37.6 point whilst electric dryer

is only 22.1 point. In fossil fuels and respiratory effect

from inorganic substances, electric dryer has much less

impact than paper towel. Respiratory effect is con-

sidered to be the most important category as human

health is highly valued, while fossil fuel has major role

in economic drive. A high on carbon dioxide emission

from paper towel life cycle to the atmosphere is

increasing potential of global warming that plays

significant role in climate change. Thus paper towel has

sig-nificant effect on both social as well as the

environment

Table 6 Cost calculation of using paper towel compared to electric dryer in a given functional unit

Description Unit Value

Price cent/sheet 6

Paper required for 5 years sheets 260,000

Financial cost A$ 15,600

Price cent/kWh 14

Electricity used for 5 years kWh 1,083

Financial cost A$ 152

Paper towel

Electricity for hand dryer

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Conclusion And Recommendation

In conclusion, electric hand dryer by means of hand

drying method surpasses paper towel toward envir-

onment sustainability performan-ces. The University of

Melbourne is recommen-ded to consider utilization of

electric dryer for replacing paper towel in the entire

campus toilet. Improvement to reduce landuse should

be targeted for optimum system. Landuse improve-

ment can be addressed through best practice in mining.

Implementing this approach will pre-vent environ-

mental damage and social impact, better mineral

exploration access, higher reli-ability of the outcomes,

less risk and resistance from the key stakeholder,

suppress financial cost in the closure and rehabilitation,

and improved liability of post cloure (Envir-onment

Australia, 2002). Therefore by reducing landuse

damage, mineral, radiation, carcinogen, and climate

change damages can be improved as well. The

university may support the program by providing

research assistance to the in-dustries.

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A., & Hardcastle. (1994). Hand drying: A

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Proper hand drying is a fundamental part of the hand hygiene process looking at optimizing the elimination of potentially pathogenic microbes. This research compared the effectiveness of three different hand drying methods—paper towels, the use of warm air dryers in stationary hands position, and the use of air drying while hand rubbing—and their potential for cross-contamination of other users and the surrounding environment. One hundred sixty samples were collected from finger pads and palms, before and after drying. The outlet of the air dryers, air current emitted from the air dryers, and washroom environment air were also tested. The study reported that paper towels were more successful in eliminating bacteria and lead to less contamination to the washroom environment compared to the air dryers. The average number of bacteria obtained from volunteers using hand air dryer while hand rubbing was significantly higher than drying with air dryer while holding hands stationary. 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The method of hand drying may serve as a risk factor of cross-contamination from users to the environment and subsequent users and as reservoirs of drug-resistant bacteria in public washrooms. 1. Introduction Hand hygiene has been documented as the easiest and the most efficient method existing in a number of settings to minimize the risk of infection transmission, including healthcare settings, food industry, schools, and other public locations [1–3]. Indeed, wet hands have shown higher probability both of getting microorganisms from polluted objects and of transmitting them to uncontaminated matters [4, 5]; hence, proper hand drying after washing is an important aspect of the process. Given that, it has become noticeable that hand drying is vitally important for preventing diseases transmission, since bacteria more likely multiply in humid environments and water is easily transferred between objects [6, 7]. As hand washing does not eliminate all microorganisms, the drying method can affect the number of microbial dispersals from washed hand to the surrounding environment but knowledge about which drying methods contribute least to users and environmental contamination is scarce. A small number of studies comparing the efficiency of warm air dryers to paper towels were carried out focusing generally on the number of microorganisms left on the hands after drying [8–13]. These findings have revealed that the number of bacteria left on the hands depends primary on the type of microbe, the time and the method of drying (rubbing amount), and the portion of the hand examined. The majority of these studies have shown that any method has its benefits and limitations but that, with any drying process, satisfactory results can be obtained if the hands are fully dried by the technique. Paper towels and hot air dryers are still the most widely used methods of hand drying in public washrooms. Some researchers suggested an increase in bacteria by drying with paper towels in comparison to drying with a hot air dryer [14]. Meanwhile, a study conducted by Gustafson et al. [9] revealed no statistically significant differences in the effectiveness of the hand drying methods including paper towels and warm air dryers for eliminating bacteria from washed hands. Redway and Fawder [15] attributed the decrease in the number of bacteria when using paper towels compared to warm air dryers to the ability of the paper towels to dry hands more efficiently. It has been reported that even though air dryers effectively dry the hands as paper towels, the bacterial growth on the hands still increased. Furthermore, there is conflicting evidence about whether the hand drying methods differ in their tendency to aerosolize and spread microbes. Several studies have indicated that drying hands with warm air dryers can enhance the aerosolization of microorganisms [16], although others have shown that the tendency of drying methods to aerosolize microorganisms is limited [10]. Additionally, some studies demonstrated the risk of potential aerosolization of microorganisms from trash cans as they were often uncovered and placed directly below the hand dryers [17]. A recent study conducted by researchers at Connecticut University and Quinnipiac University has shown that warm air hand dryers in public toilets may suck bacteria from the air and dump them into the washed hands of users [17]. They stated that most of the hand dryers’ bacterial growth had originated from air in the washroom because the number of microbes in the plates exposed to hand dryer’s air had dropped by 75% after using particulate air (HEPA) filters to the dryers. As countless people belief that using hand washing and drying facilities in public washrooms is safe, those facilities may also be possible sources for pathogenic microorganisms to be transmitted due to their environments suitable for the survival of many pathogenic bacteria such as E. coli, S. aureus, B. cereus, and Pseudomonas aeruginosa (P. aeruginosa) [7]. In addition to the scarcity of research evaluating the different hand drying methods and the environment’s air in the public washrooms in the Kingdom of Saudi Arabia (KSA), this study, however, aimed to assess the different methods of hand drying and their role in contaminating washroom’s environment and antibiotic susceptibilities of isolated bacteria. 2. Materials and Methods 2.1. Sample Collection This study was conducted in the different academic institutions’ washrooms in the KSA to evaluate the efficacy of hand drying methods. The study involved 20 adult volunteers who agreed to participate in this research. Persons with any skin or nail lesions were excluded. The samples obtained after hands were washed with nonantibiotic soap and after drying with different methods. These methods include (1) drying with a paper towel, (2) drying with air dryer while keeping the hands steady, and (3) drying with air dryer while hand rubbing. 2.2. Evaluation of the Number of Microorganisms on Hands after Washing and Drying Participants were instructed to wash their hands and dry them in warm air hand dryers; the following day, the same subjects were requested to use paper towels. The hands were dried in random sequence to eliminate any confusing effect. The subject washed for 30 seconds in running water with a nonantibacterial soap and then rinsed for 10–20 seconds to remove all soap. Each subject, after washing and rinsing, dried the hand with paper towels or the warm air hand dryer. For drying with the paper towels, fifteen seconds was used, and a single 30-second cycle of the warm air hand dryer was used. After washing and drying, samples were taken from the fingers and palms. The finger and palm samples were taken by contact plate methods, and the finger pads and the palms were pressed on Petri dishes containing nutrient agar. The plates were then incubated at 37°C for 48 hours and bacterial total counts were estimated after incubation. 2.3. Potential Contamination of Other Users and the Washroom Environment Using Hand Air Dryers The surrounding environment was assessed for the contamination of bacteria by warm air dryers in the washrooms of four colleges with three different methods including (1) plates exposure to the air outlet of the turned-on warm air dryers, (2) placing the plates in front of the turned-off dryer for 3 minutes (min), and (3) placing Petri dishes at least one meter away from the dryer in the washroom for 30 min. Additionally, the inner surface of air dryers’ nozzles was swabbed with sterile swabs moisturized in normal saline to collect samples. The samples were collected at several locations at the university. The plates were incubated for 48 hours at 37°C and bacterial total counts were estimated after incubation. The bacterial isolates were identified by the conventional methods such as morphological and cultural characteristics and biochemical characteristics. 2.4. Antibiotic Sensitivity Assay Antibiotic sensitivity was tested on sixteen bacterial isolates obtained from the samples of the washroom’s environment following Laboratory Standards Guidelines for antimicrobial susceptibility assay [7, 18, 19]. The resistance to antimicrobials was tested using disc diffusion assay (Kirby and Bauer, 1966). Bacterial suspensions prepared in sterilized saline were evenly spread with sterile swabs on Muller Hinton Agar with turbidity equal to that of the 0.5 McFarland standard. The following antibiotics were used: penicillin G (10 units), erythromycin (15 μg), ampicillin (10 μg), cephalothin (30 μg), clindamycin (2 μg), and co-trimoxazole (25 μg). The plates were incubated overnight at 35–37°C; then the inhibition zones around the antibiotic disks were measured. 2.5. Data Analysis Data were analyzed using the Mann–Whitney test to assess significance where statistical significance was expressed as . Graphs were performed using GraphPad Prism version 8.4.3, San Diego, California, USA. 3. Results 3.1. Assessment of Microorganisms’ Number on Hands after Washing and Drying The air dryer increased the bacterial average numbers on both the palms and finger pads of subjects. In the current study, paper towel was found to be superior to the air dryer for hand palms and finger pads (Figure 1). The number of residual bacteria on the fingers was substantially increased in the participants who had dried their hands with the air dryer compared to the drying with paper towels. The result was significant at for finger using paper towel (140.1) compared to drying with the air dryer (276.6). On hands dried with a paper towel, recovered bacteria were significantly lower compared to drying hands with the air dryer (). As shown, the number of bacteria obtained from participants with hand towels and an air dryer varied greatly (Standard Deviation (SD): 95.6 and 33.6, respectively).

Recovery of EACH-USP Organic Waste as an Instrument for Achieving Sustainability

Chapter

May 2018

The large generation of urban solid waste in Brazil has as one of its characteristics the predominance of the organic fraction. When disposed in landfills, this fraction can cause public and environmental health problems, increase the emission of greenhouse gases and contribute to a reduction in the landfills’ lifespan. Considering that university restaurants are great generators of organic waste, this research tries to approach how the valorization of these wastes using the biodigestion process would contribute to the increase of the sustainability at the campus EACH-USP. This management model avoids the disposal of organic waste in landfills (reducing emissions from the transport of waste to landfills), can generate electric energy and can provide a by-product with potential fertilizer. For this approach, organic waste generation data on campus were analyzed, also was estimated the energetic potential of this waste and the avoided CO2 emissions, through the adaptation of the GHG protocol tool. The results indicate that the management of organic waste is very important for sustainability in the context of university campuses, since its valuation focuses directly on the environmental issue.

Too loud? Do powered hand dryers violate federal noise exposure standards?

Article

Apr 2020
Am J Otolaryngol

Objective The aim of this study was to determine if high-powered air hand dryers produce sufficient noise to warrant concern over acoustic trauma as determined by federally established standards. Study design Prospective observational field data collection Setting Urban and suburban community Subjects and methods Using a NIOSH developed and calibrated soundmeter app, powered hand dryers were measured throughout two metropolitan areas. Ear level measurements were performed while drying wet hands. Recorded variables included average LAeq, Time-Weighted Average, Max and Peak Levels, Noise Dose, and Projected Dose according to NIOSH and OSHA standards, and all three major weighting networks (A, C, and Z). Results Fifty-four trials were performed at 27 locations. Average dryer run time was 28.9 s (range 14–45 s). Average LAeq (dBA), average maximum level (dBA), and average TWA (dBA) were 90.46 ± 5.32, 94.86 ± 5.73, 59.90 ± 6.80, respectively. The noise generated exceeded published manufacturer specifications. However, even with estimated cumulative daily exposure, the noise generated by these dryers did not exceed federal safety standards. Conclusions Air-powered hand dryers produce noise output at a level that many would find subjectively uncomfortable with some brands/models consistently producing noise in excess of 90 dBA. Nonetheless, these dryers do not produce sound exceeding NIOSH standards for noise exposure.

Evaluation of Environmental Impacts from a Molecular Evolution Laboratory’s Waste Management System—A Brazilian Case Study

Chapter

May 2018

This study proposes an integrated waste management system to a university laboratory aiming: (i) waste prevention as the precursor activity; (ii) to distinguish not hazardous chemicals waste and enable recycling, and; (iii) to recycle solvents. The main objective is to decrease negative environmental impacts caused by studies conducted in this type of laboratory. A life cycle assessment was conducted to infer these impacts. Material consumption data were collected on site while recent studies were used for environmental impacts. Two scenarios were evaluated: (1) the current situation, where ethyl alcohol is recycled, chemical waste is incinerated and non-hazardous waste is landfilled; (2) a future scenario, where waste prevention is implemented; ethyl alcohol, gloves, plastic pipette tips and tubes are recycled; chemical waste is incinerated, and; paper waste is composted. The second scenario decreased considerably the environmental impacts and suggested that there is a potential for plastic waste recycling, yet it is necessary an economic evaluation to determine its feasibility. The pursue of waste prevention through new initiatives (e.g. electrical hand dryers) may also represent another gain on environmental and economic impacts. This methodology proved to be effective in achieving its purpose and it can be used to improve waste management in similar situations. Yet, the importance of this study relies on the inclusion of waste prevention as a first step to improve the current waste management system and also by including the assessment of its environmental impacts as a way to effectively decrease them. It important to highlight that is a type of waste common in most of the universities.

Environmental and Economic Perspectives in the Analysis of Two Options for Hand Drying At an University Campus

Article

Full-text available

Apr 2017

— Environmental criteria can be part of global energy policies for the establishment of support and development actions for different technologies. Minimization of greenhouse gas emissions is a benefit to all citizens of the world, as these emissions have global scope. The objective of this study was to determine the best option for hand drying in a university campus building, from economic and environmental viewpoints, for a range of commercially available equipment. For the economic analysis, the capital and operation costs were considered along with the lifetime of the equipment. For the environmental analysis, the Life Cycle Assessment methodology was utilized. Eight options for hand drying were considered on an annual basis: five electric hand dryers and three types of paper towels. Electric hand dryers presented lower annual environmental impacts and lower annual economic costs. It is discussed that environmental impacts can and must be an active factor for the selection of one technology or another. The novelty of this study was the application of the LCA methodology to compare the carbon footprint associated with different commercially available options for hand drying in public restrooms, providing information to the consumer on which alternative is more environmentally-friendly.

Greenhouse gas emissions from a Western Australian finfish supply chain

Article

Dec 2014
J CLEAN PROD

Greenhouse gas (GHG) emissions in the form of carbon dioxide equivalent (CO2 – eq) from two Western Australian finfish supply chains, from harvest to retail outlet, were measured using streamlined life cycle assessment methodology. The identification of interventions to potentially reduce the GHG emissions was determined from the results obtained. Electricity consumption contributed to the highest GHG emissions within the supply chains measured, followed by refrigeration gas leakage and disposal of unused fish portions. Potential cleaner production strategies (CPS) to reduce these impacts included installing solar panels, recycling the waste, good housekeeping in refrigeration equipment maintenance, and input substitution of refrigeration gas. The results show a combination of these strategies have the potential to reduce up to 35% of the total GHG emissions from fillet harvest, processing and retail.

Environmental Life Cycle Assessment of Goods and Services: An Input-Output Approach

Book

Full-text available

Jan 2006

Environmental life cycle assessment is often thought of as cradle to grave and therefore as the most complete accounting of the environmental costs and benefits of a product or service. However, as anyone who has done an environmental life cycle assessment knows, existing tools have many problems: data is difficult to assemble and life cycle studies take months of effort. A truly comprehensive analysis is prohibitive, so analysts are often forced to simply ignore many facets of life cycle impacts. But the focus on one aspect of a product or service can result in misleading indications if that aspect is benign while other aspects pollute or are otherwise unsustainable. This book summarizes the EIO-LCA method, explains its use in relation to other life cycle assessment models, and provides sample applications and extensions of the model into novel areas. A final chapter explains the free, easy-to-use software tool available on a companion website. (www.eiolca.net) The software tool provides a wealth of data, summarizing the current U.S. economy in 500 sectors with information on energy and materials use, pollution and greenhouse gas discharges, and other attributes like associated occupational deaths and injuries. The joint project of twelve faculty members and over 20 students working together over the past ten years at the Green Design Institute of Carnegie Mellon University, the EIO-LCA has been applied to a wide range of products and services. It will prove useful for research, industry, and in economics, engineering, or interdisciplinary classes in green design. © 2006 by Resources for the Future. All rights reserved. All rights reserved.

Hot-air hand driers

Article

Sep 1989
J HOSP INFECT

Hot air electric hand driers compared with paper towels for potential spread of airborne bacteria

Article

Feb 1987
J HOSP INFECT

Hot air hand driers are increasingly used in both public areas and hospitals, but there is little literature on their bacteriology. Four units were examined by comparing the bacterial aerosols released from hands during use by sets of twelve subjects with those released by paper towels. Tests on two units also included hand imprints on agar plates for detection of residual bacteria. No significant difference between aerosols liberated by towels and driers were observed for two units, while the other two generated significantly fewer aerosols than towels. Impression plates revealed similar numbers of bacteria on the hands after drying by either method. Hot air hand driers appear safe from a bacteriological viewpoint.

Survival of thermophilic Campylobacters on fingertips and their elimination by washing and disinfection

Article

Nov 1987

A simple impression-plate technique has been used to investigate the survival of four thermophilic campylobacter strains applied to fingertips. Campylobacters suspended in 0.1% peptone water and dried on the fingertips survived for different periods of time ranging from less than 1 to greater than or equal to 4 min. However, campylobacters suspended in chicken liquor or blood survived for much longer periods. The most resilient organism was Campylobacter jejuni NCTC 11392 which, when suspended in 50% horse blood, survived for an hour. Suspensions containing 10(6)-10(7) organisms prepared in 50% blood and dried on to fingertips were removed by thorough hand washing with either soap and water or water alone followed by drying on paper towels, but persisted on wet hands. The organisms were also eliminated by wiping the hands with a tissue saturated with 70% isopropyl alcohol for 15 sec.

AGO Factors and Methods Workbook: Australian Greenhouse Office, Department of the Environment and Heritage

Jan 2006

AGO. (2006). AGO Factors and Methods Workbook: Australian Greenhouse Office, Department of the Environment and Heritage.

Hand and hair dryer: 2006 -2007 catalog. Retrie-ved

May 2006

Americandryer

AmericanDryer. (2006). Hand and hair dryer: 2006 -2007 catalog. Retrie-ved May 27, 2007

Hand-drying me-thods. Nursing times

Jan 1987
71-74

M Blackmore

Blackmore, M. (1987). Hand-drying me-thods. Nursing times, 71-74.

Overview of best practice environmental ma-nagement in mining: Environment Australia, Department of the Environment and Heritage

Jan 2002

Environmentaustralia

EnvironmentAustralia. (2002). Overview of best practice environmental ma-nagement in mining: Environment Australia, Department of the Environment and Heritage.

Hand drying -A survey of efficiency and hygiene

Jan 1993

B Knights
C Evans
S Barrass
B Mchardy

Knights, B., Evans, C., Barrass, S., & McHardy, B. (1993). Hand drying -A survey of efficiency and hygiene. London, UK: The Applied Ecology Research Group, University of Westminster.

Introduction to LCA with SimaPro 7: Product Ecology Con-sultants