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Human and Environmental Toxicity of Sodium Lauryl Sulfate (SLS): Evidence for Safe Use in Household Cleaning Products



Environmental chemical exposure is a major concern for consumers of packaged goods. The complexity of chemical nomenclature and wide availability of scientific research provide detailed information but lends itself to misinterpretation by the lay person. For the surfactant sodium lauryl sulfate (SLS), this has resulted in a misunderstanding of the environmental health impact of the chemical and statements in the media that are not scientifically supported. This review demonstrates how scientific works can be misinterpreted and used in a manner that was not intended by the authors, while simultaneously providing insight into the true environmental health impact of SLS. SLS is an anionic surfactant commonly used in consumer household cleaning products. For decades, this chemical has been developing a negative reputation with consumers because of inaccurate interpretations of the scientific literature and confusion between SLS and chemicals with similar names. Here, we review the human and environmental toxicity profiles of SLS and demonstrate that it is safe for use in consumer household cleaning products.
Sodium lauryl sulfate (SLS), also known as sodium lauril sulfate
or sodium dodecyl sulfate, is an anionic surfactant com-
monly used as an emulsifying cleaning agent in household
cleaning products (laundry detergents, spray cleaners, and
dishwasher detergents). e concentration of SLS found
in consumer products varies by product and manufacturer
but typically ranges from 0.01% to 50% in cosmetic prod-
and 1% to 30% in cleaning products.
SLS can be
synthetic or naturally derived. is chemical is synthe-
sized by reacting lauryl alcohol from a petroleum or plant
source with sulfur trioxide to produce hydrogen lauryl sul-
fate, which is then neutralized with sodium carbonate to
produce SLS.
SLS (CAS# 151–21–3; MW 288.38 g/mol; pH 7.2) is
a nonvolatile, water-soluble (100150 g/L at room tempera-
ture) compound with a partition coecient (log P
) of 1.6
making it a relatively hydrophilic compound.
hydrophilic compounds have a low soil/sediment adsorption
coecient and low bioconcentration factors (BCFs). e BCF
for SLS ranges from 2.1 to 7.1.
Down-the-drain cleaning
products release SLS into the environment via household
wastewater systems. In the environment, .99% of SLS read-
ily biodegrades into nontoxic components per the OECD
301 standard.
Consumers may be exposed to SLS by using products
that contain the ingredient. Exposure to SLS from house-
hold cleaning products depends on the frequency of house-
hold cleaning activities, which is reported as being 12 times
per week on average.
e intended application of detergents
and cleaners should not result in direct contact with product
ingredients; however, misuse of the product could potentially
cause dermal (skin and ocular) or inhalation exposure.
exposure to cleaning products is unlikely but has occurred
mostly in children – because of accidental ingestion.
With regular use of cleaning products, the delivered dose
of SLS from dermal or inhalation exposure is expected to
be low given the low volatility and dermal absorption rate
of SLS.
Since the early 1990s, misconstrued information on the
human and environmental toxicity of SLS has led to consumer
confusion and concern about the safety of SLS as an ingredient
Human and Environmental Toxicity of Sodium Lauryl
Sulfate (SLS): Evidence for Safe Use in Household
Cleaning Products
Cara A. M. Bondi
, Julia L. Marks
, Lauren B. Wroblewski
, Heidi S. Raatikainen
Shannon R. Lenox
and Kay E. Gebhardt
Research and Development, Seventh Generation Inc., Burlington, VT, USA.
Department of Environmental and Occupational Health
Sciences, University of Washington, Seattle, WA, USA.
A BS TR ACT: Environmental chemical exposure is a major concern for consumers of packaged goods. e complexity of chemical nomenclature and wide
availability of scientic research provide detailed information but lends itself to misinterpretation by the lay person. For the surfactant sodium lauryl sulfate
(SLS), this has resulted in a misunderstanding of the environmental health impact of the chemical and statements in the media that are not scientically
supported. is review demonstrates how scientic works can be misinterpreted and used in a manner that was not intended by the authors, while simulta-
neously providing insight into the true environmental health impact of SLS. SLS is an anionic surfactant commonly used in consumer household cleaning
products. For decades, this chemical has been developing a negative reputation with consumers because of inaccurate interpretations of the scientic litera-
ture and confusion between SLS and chemicals with similar names. Here, we review the human and environmental toxicity proles of SLS and demonstrate
that it is safe for use in consumer household cleaning products.
KEY WORDS: surfactant, media claims, product formulation, ingredient safety review
CITATION: Bondi et al. Human and Environmental Toxicity of Sodium Lauryl Sulfate
(SLS): Evidence for Safe Use in Household Cleaning Products. Environmental Health
Insights 2015:9 27–32 doi: 10.4137/EHI.S31765.
TYPE: Consise Review
RECEIVED: July 17, 2015. RESUBMITTED: August 24, 2015. ACCEPTED FOR
PUBLICATION: August 26, 2015.
ACADEMIC EDITOR: Timothy Kelley, Editor in Chief
PEER REVIEW: Six peer reviewers contributed to the peer review report. Reviewers’
reports totaled 2,763 words, excluding any condential comments to the academic editor.
FUNDING: JLM’s work as a scientic writer for this manuscript was funded by Seventh
COMPETING INTERESTS: All authors except JLM were, at the time of writing this
manuscript, employed by and receiving salaries and research support from Seventh
Generation, Inc., which manufactures household cleaning products that contain sodium
lauryl sulfate. JLM received personal fees from Seventh Generation for her contributions
to this manuscript as a scientic writer.
COPYRIGHT: © the authors, publisher and licensee Libertas Academica Limited. This is
an open-access article distributed under the terms of the Creative Commons CC-BY-NC
3.0 License.
Paper subject to independent expert blind peer review. All editorial decisions made
by independent academic editor. Upon submission manuscript was subject to anti-
plagiarism scanning. Prior to publication all authors have given signed conrmation of
agreement to article publication and compliance with all applicable ethical and legal
requirements, including the accuracy of author and contributor information, disclosure
of competing interests and funding sources, compliance with ethical requirements
relating to human and animal study participants, and compliance with any copyright
requirements of third parties. This journal is a member of the Committee on Publication
Ethics (COPE).
Published by Libertas Academica. Learn more about this journal.
Bondi et al
in household products.
As scientic literature is inherently
vulnerable to misinterpretation by the general public, health
and safety claims made by marketing campaigns do not always
align with the latest peer-reviewed scientic evidence. Often-
times, consumer product claims use language in ways that can
be misleading to the average consumer. Review of the human
and environmental toxicity proles of SLS is warranted to elu-
cidate the known risks and benets of using SLS in household
cleaning product formulation.
Review of SLS Toxicity Proles
Here, we provide a review of the human and environmental
toxicity proles for SLS in order to address the most common
consumer concerns about the ingredient. Unsubstantiated
claims regarding the safety of SLS found in print and online
media are used to exemplify the origin of several common
misconceptions. Each human health and environmental claim
is assessed against peer-reviewed scientic evidence for accu-
racy and validity. is review clearly demonstrates the known
risks and benets of using household cleaning products that
contain SLS. Table 1 summarizes the available toxicology
data on SLS.
Human Toxicity Prole
Acute toxicity. Ocular irritation. Like most chemicals,
SLS can be irritating to the eye when delivered neat as a raw
material or at high concentrations. At concentrations ,0.1%
(w/w), SLS is nonirritating to the eyes of laboratory ani-
For this reason, it is imperative for consumer product
manufacturers to test nished products for ocular irritation.
e U.S. Consumer Product Safety Commission (CPSC;16
C.F.R. §1500) requires consumer product manufacturers to
perform irritation tests that appropriately characterize the
ocular toxicity of the product.
Manufacturers are required
to label the product with the appropriate warnings and rst
aid information according to the mandatory labeling require-
ments of the CPSC.
SLS is cited as causing severe eye damage and blind-
ese claims typically point to a study published by
Green et al.
in the journal Lens and Eye Toxicity Research. e
study shows that after the occurrence of physical or chemical
damage to the eye, corneal exposure to a high concentration
of SLS can result in a slowed healing process. e ndings
presented by Green et al.
do not suggest that ocular exposure
to consumer products containing SLS causes blindness or
severe damage to the cornea.
In response to the media attention generated by a
company promoting the anti-SLS campaign at the time
Green, the study’s lead author, was interviewed regarding
this work. Green stated that the company had misquoted
the results and made claims that were not supported by his
His legal counsel later issued a letter to the com-
pany stating:
your citation of his work was not simply a misinterpreta-
tion, it was plainly wrong. By citing his research in support
of erroneous conclusions, you have libeled Dr. Green. In fact,
[you have] even attributed quotations to Dr. Green which he
has never written or spoken, and which he would not ever
write or speak.
In this case, the dissemination of misconstrued results
not only provided a disservice to the general public but also
caused serious repercussions for the scientic researchers.
A second erroneous ocular health claim made about SLS
is its link to cataract formation.
Claims about SLS causing
cataract formation tend to cite a 1987 study in the Journal of
Biological Chemistry.
is study
along with several oth-
uses SLS to model cataract formation experimentally.
In a controlled laboratory environment, cataract formation
can be induced by immersing the lens of the eye in a concen-
trated solution of SLS. While concentrated SLS is useful as an
experimental irritant, this is not relevant to evaluating human
exposure to SLS in household cleaning products. Ocular irri-
tation has been induced in vivo using SLS concentrations
equivalent to a rinse-o personal care product containing 20%
However, this was achieved after the eyes of laboratory
animals were repeatedly exposed to 0.5 mL of shampoo for
14 days.
While SLS is useful in studying the formation and
repair of cataracts in laboratory settings, studies of this nature
are not appropriate for assessing the risk of human exposure to
SLS in cleaning products.
Furthermore, it should be noted that the anatomy of the eye
renders direct exposure of the lens to SLS impossible, as it is deep
within the eye protected by the cornea, and therefore, not vul-
nerable to exposure through typical consumer product usage.
As such, a causal relationship between SLS in consumer products
and cataract formation is not scientically supported.
Table 1. Toxicity of SLS (CAS# 151–21–3).
(96 HRS;
Lethal dose or
concentration (50%)
1288 mg/kg* 2000–20000 mg/kg*
.3900 mg/m
100 mg/kg/day**
1–12 mg/L*
Notes: *From SLS product manufacturer MSDS (Stepan Company, IL)
; **From OECD Screening Ingredient Data Set.
Human and environmental toxicity of SLS
Dermal irritation. Dermal toxicity studies demonstrate
that 24-hour exposure to a 1–2% (w/w) solution of SLS can
increase the transepidermal water loss of the stratum corneum
– the outer most layer of the skin – and cause mild yet revers-
ible skin inammation.
Human patch tests (typically a
24-hour exposure) conrm that SLS concentrations .2% are
considered irritating to normal skin.
Dermal irritation
also tends to increase with SLS concentration and the dura-
tion of direct contact.
In reality, dermal exposure to SLS in
cleaning products is more likely to last a matter of minutes
rather than hours.
Cleaning products that contain SLS have the potential
to be dermal irritants if not formulated properly, but products
that contain SLS are not necessarily irritating to the skin.
Proper formulation development includes strategies for miti-
gating irritation (like adding cosurfactants) and can produce
products with SLS that are mild and nonirritating to the skin.
Owing to the irritation potential, however, consumer product
manufacturers are required to conduct testing to appropriately
characterize the dermal toxicity of the product and label the
product with the appropriate warnings and rst aid infor-
mation according to the mandatory labeling requirements of
the CPSC.
Another assertion is that SLS is corrosive to the skin.
Corrosive chemicals are those that cause irreversible damage
or destruction of the skin as a result of direct skin contact.
Material safety data sheets for SLS do not categorize this
chemical as a corrosive material and do not require any special
handling precautions.
As such, statements about SLS being
corrosive to the skin are inaccurate.
Oral toxicity. Acute oral toxicity refers to the immediate
adverse eects that result from ingesting a substance. e acute
oral toxicity of individual ingredients and formulated products
is measured in terms of the median lethal dose (LD
), which
indicates the quantity by weight (typically in milligrams of
substance per kilograms of body weight) required to kill
half of the laboratory animals receiving that dose. Ingredi-
ents and formulations with an LD
of $5,000 mg/kg are
classied as nontoxic.
e acute oral toxicity of SLS as a
raw material is reported to range from 600 to 1,288 mg/kg
(in rats), which indicates that SLS is toxic to rats as a stand-
alone ingredient.
e acute oral toxicity of SLS is not disputed, but it is
relevant to the overall safety review of SLS. It is important to
remember that the toxicity of a formulated consumer product
is dictated by the formulation as a whole, not by the toxic-
ity of an individual ingredient. is means that while SLS
as a raw material at 100% concentration may have a LD
,5,000 mg/kg, formulations that contain diluted or lesser
concentrations of SLS are not necessarily toxic and can even be
nontoxic. is holds true for the use of SLS in food products
as well and explains why SLS is listed on the U.S. Food and
Drug Administration (FDA) list of multipurpose additives
allowed to be directly and indirectly added to food.
too, that every chemical has a toxic dose, and many common
foods can be classied as toxic. For example, sodium chloride
(table salt) has an LD
of 3,000 mg/kg, making it moderately
toxic by denition.
Chronic toxicity. Carcinogenicity. e most egregious
claim by far is that SLS is carcinogenic.
e origin of this
claim is uncertain, but it is likely to have derived from multiple
misinterpretations of the scientic literature. ere is no sci-
entic evidence supporting that SLS is a carcinogen.
is not listed as a carcinogen by the International Agency for
Research on Cancer (IARC); U.S. National Toxicology Pro-
gram; California Proposition 65 list of carcinogens; U.S. Envi-
ronmental Protection Agency; and the European Union. In
1998, the American Cancer Society (ACS) published an arti-
cle attempting to correct the public’s misconception of SLS.
Regardless, false claims about SLS proliferated throughout
the digital media, causing consumers to develop signicant
concerns about SLS in household cleaning products.
e perception that SLS is carcinogenic is often based
on studies that use the ingredient to evaluate the carcino-
genicity of other agents. An article written by Birt et al.
commonly cited as supporting the carcinogenicity claim for
SLS. However, this is another example of public misinterpre-
tation and the resulting dissemination of inaccurate informa-
tion. In the study by Birt et al.
, SLS was used as a vehicle
to process the agent being tested. No evidence supporting the
carcinogenic eect of SLS was reported. It is apparent that
the common use of SLS as a solubilizing agent in toxicology
studies has led to the public’s confusion around the chronic
toxicity of SLS.
Other claims denouncing SLS as a carcinogen point to
a chemical reaction between SLS and formaldehyde that cre-
ates nitrosamines as a by-product.
However, it is not possible
for SLS and formaldehyde to react and form a nitrosamine.
Nitrosamines contain two nitrogen atoms, but neither SLS
nor formaldehyde contain nitrogen atoms. erefore, the
two cannot react to form a nitrogen-containing nitrosamine.
Although nitrosamines have been associated with several
types of cancer and many are classied by IARC as known,
possible, or probable carcinogens depending on the chemical
they cannot be associated with the presence and
use of SLS.
Another carcinogenic by-product, 1,4-dioxane, is falsely
associated with SLS.
1,4-dioxane is categorized as possibly
carcinogenic to humans by IARC,
and the potential for some
surfactants like sodium laureth sulfate (also called sodium
lauryl ether sulfate or SLES) – to be contaminated with
1,4-dioxane during the ethoxylation process is well estab-
Barring contamination by manufacturing equipment,
surfactants that are not ethoxylated, such as SLS, do not share
the same risk of 1,4-dioxane contamination. It is important to
note, however, that potential for cross-contamination during
manufacturing exists. Manufacturers of SLS and products
containing SLS can perform chemical analyses to conrm if
Bondi et al
there are detectable levels of 1,4-dioxane in the SLS ingredient
or formulated consumer product.
Organ toxicity. It is often claimed that SLS absorbs
into the blood stream, builds up in the heart, liver, lungs and
brain, and causes damage.
Claims of this nature often
cite the Cosmetic Ingredient Review (CIR) Final Report
on the safety of SLS, which contains an extensive review
of the absorption and excretion of SLS in humans and ani-
However, the CIR concludes that while SLS can be
absorbed through the skin when applied directly, the major-
ity of the material remains in or on the skin surface. SLS that
is absorbed into the bloodstream is quickly metabolized by
the liver into more water-soluble metabolites that are rapidly
excreted through the urine, feces, and sometimes expired
ere is no evidence in the CIR report or in
the scientic literature at large that supports the accumula-
tion of SLS in vital organs and associates it to systemic tox-
icity or vital organ damage.
As such, accusations that
SLS will bioaccumulate in humans and cause organ damage
are inaccurate.
Dermatological eects. Hair loss. e CIR report
also cited as supporting the claim that SLS can cause hair loss
and baldness.
e CIR report states as follows:
Autoradiographic studies of rat skin treated with radio-
labeled Sodium Lauryl Sulfate found heavy deposi-
tion of the detergent on the skin surface and in the hair
follicles; damage to the hair follicle could result from
such deposition.
e report goes on to say that high concentrations of SLS
may aect the hair, but no evidence is presented to show that
SLS exposure causes hair loss. Rather, the report recommends
that cosmetic products applied to the skin not contain concen-
trations of SLS .1% due to its potential to deposit on hair fol-
In addition, the report states that additional research
would be required to elucidate the true eects of the deposi-
tion. As of 2015, no scientic evidence has been produced to
suggest that dermal exposure to SLS causes hair loss.
A study published in 1998 by the European Journal of
Dermatology is also cited as supporting claims that SLS causes
hair loss.
is study investigates the eects of oxidative stress
on skin irritation and uses SLS as an experimental irritant.
ere is no discussion of hair loss. As in the CIR report, the
researchers of this study
identied the deposition of SLS on
the root sheath of the hair follicle but did not draw conclusions
about the eects of this deposition on the hair. e study
no way suggests that SLS is responsible for, or contributes to,
chronic hair loss. In general, no data have been generated to
elucidate the long-term eects of SLS deposition on hair fol-
licles, but based on the widespread and long-term use of SLS
in hair care products, such an eect is highly unlikely. Overall,
claims that associate the use of SLS-containing products with
hair loss are not scientically supported.
Sensitization. Another unsubstantiated claim about SLS
is that it can cause severe dermal sensitization.
A sensi-
tizer is a substance that causes hypersensitivity through an
allergic or photodynamic process, which becomes evident
on reapplication of the same substance on the skin. ere is
no scientic evidence to support that SLS has sensitization
potential. SLS is not included on any lists of known or sus-
pected sensitizers.
erefore, stating that SLS is a sensitizer
is inaccurate.
Other chronic toxicities. To a lesser extent, claims about
SLS causing chronic adverse health eects such as muta-
genicity, reproductive and development toxicity, neurotox-
icity, and endocrine disruption – have been made without
adequate substantiation.
erefore, it is worth mentioning
that SLS has no known chronic health eects. According
to the National Library of Medicine’s TOXNET
SLS is not classied as a known or suspected mutagen,
reproductive or developmental toxicant, neurotoxicant, or
endocrine disruptor.
Environmental Toxicity Prole
Use and disposal of cleaning products release SLS into the
environment via household wastewater systems. erefore,
the environmental toxicity prole is an important consider-
ation when evaluating the risks and benets of using SLS in
household cleaning product formulation. Although the envi-
ronmental toxicity of SLS does not appear to be a point of
debate in online communications, a concise review is included
to demonstrate the end-use eect of this ingredient.
Aquatic toxicity. Aquatic toxicity refers to the short-term
adverse eects that result from the exposure of aquatic life to
a chemical or formulation. is type of toxicity is measured
in terms of the median lethal concentration (LC
), which
indicates the quantity by volume (typically reported as mil-
ligrams of substance per liter of water) required to kill half of
the experimental population exposed to that dose. Ingredients
or formulations with an LC
of $100 mg/L are classied as
nontoxic to aquatic life.
As a raw material, the LC
for SLS is reported between
1 and 13.9 mg/L after 96 hours, categorizing it as moderately
toxic to aquatic life.
Like acute oral toxicity, aquatic
toxicity values for individual ingredients do not directly cor-
respond with the toxicity of formulated consumer products.
is means that while SLS is moderately toxic to aquatic life
in its raw material form, product formulations that contain
dilutions of SLS are not necessarily moderately toxic and, in
fact, can be nontoxic to aquatic life. However, the toxicity of
SLS depends largely on the marine species, water hardness,
and water temperature.
By the time cleaning product ingredients reach natural
waters, they are mostly degraded. Ecotoxicity studies have
determined that a surfactant concentration of 0.5 mg/L
of natural water would be essentially nontoxic to sh and
other aquatic life under most conditions.
It is suggested,
Human and environmental toxicity of SLS
however, that chronic toxicity of anionic surfactants occurs at
concentrations as low as 0.1 mg/L.
Biodegradability. e ability of a chemical to decompose
into simple, nontoxic components under ambient environmen-
tal conditions within a short period of time (typically 96 hours)
means that it is biodegradable. SLS is readily biodegradable
under aerobic and anaerobic conditions and, therefore, does
not persist in the environment.
e biodegradation of
SLS occurs via hydrolytic cleavage of the sulfate ester bond
leaving inorganic sulfate and fatty alcohol. ese fatty alcohols
undergo oxidation to produce fatty acids, which are degraded
by β-oxidation and fully mineralized and incorporated into
the biomass.
us, the decomposed by-products of SLS are
benign to the environment.
Biobased content. e biobased content of an ingredient
is a primary criterion for formulating sustainable consumer
products. e biobased content of an ingredient or formula is
the percentage of carbon molecules in the chemical or formula
that is derived from a renewable source such as coconut or
palm kernel oil. e biobased content of plant-derived SLS
is 100%, which indicates that all of the carbon in the mol-
ecule is derived from a plant source rather than a nonrenew-
able, petroleum source. By comparison, SLES a surfactant
commonly used in household cleaning product formulations
is an ethoxylated surfactant containing carbon molecules
derived from petroleum. SLES ethoxylated with petrochemi-
cals has a biobased content of 76%. From a sustainability and
environmental health perspective, sourcing surfactants such
as plant-derived SLS avoids incurring the additional environ-
mental and human health impacts caused by the extraction of
petroleum and the production of petrochemicals.
e review of SLS toxicity proles conrms that SLS is an
acceptable surfactant for use in household cleaning product
formulations from toxicological and sustainability perspec-
tives. Years of anti-SLS campaigns have led to consumer
concerns and confusion regarding the safety of SLS. Yet, the
primary concern that SLS has potential for being irritat-
ing to the eyes and skin can be easily addressed by proper
formula development and appropriate irritation testing per-
formed by the product manufacturers. SLS is considered a
sustainable material because of its 100% biobased content,
biodegradability, and low potential to bioaccumulation. Toxi-
cological data support that SLS is safe for use in cleaning
products when formulated to minimize its irritancy potential.
It is concluded that the use of SLS in cleaning product for-
mulations does not introduce unnecessary risk to consumers
or the environment because of the presence of the ingredi-
ent, and, if properly formulated and qualied, does not pose
danger to human health and safety. erefore, the perception
that SLS is a threat to human health is not scientically sup-
ported, and claims made to the contrary should be regarded
as false and misleading.
Author Contributions
CAMB conceived and designed the review and wrote the rst
draft of the manuscript. HSR, SRL, LBW and KEG con-
tributed to the writing of the manuscript. JLM is a scientic
writer and revised the manuscript to its nal version. CAMB
and JLM jointly made critical revisions to the manuscript. All
authors reviewed and approved of the nal version.
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... It is synthesized by reacting lauryl alcohol from a petroleum or plant source with sulfur trioxide to produce hydrogen lauryl sulfate, which is then neutralized with sodium carbonate to produce SLS. 24 Importantly, it is found that the use of SLS does not cause a risk to consumers or the environment. 24 The vapor pressure of SLS solutions has been studied previously. ...
... 24 Importantly, it is found that the use of SLS does not cause a risk to consumers or the environment. 24 The vapor pressure of SLS solutions has been studied previously. 25 All these results can be seen in Table 2. From these data, it can be concluded that a 1% SLS solution has essentially the same vapor pressure as pure water. ...
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The removal of micron-sized carbon black particles from capillary tubes (outer diameter 1.46 mm, inner diameter 1.12 mm, length 50.00 mm) using cyclic vacuum cavitation (VC) cleaning was investigated. As the first objective of this study, the VC apparatus was constructed. This VC setup allowed video monitoring of the cleaning process. Photographs, video recordings, and gravimetric analysis tests were used to identify the cleaning efficiencies. As the second part, the carbon black powder removal efficiencies were used to compare cyclic VC and ultrasonic cavitation (UC) cleaning. Cyclic VC coupled with deionized (DI) water was able to remove 67 ± 7% of carbon black powder from contaminated capillary tubes. Solutions of 1% sodium lauryl sulfate (SLS) in DI water successfully removed 82 ± 7% of carbon black powder using fifteen vacuum cycles at room temperature. The UC process was unable to flush the carbon black soil from the internal volume of the capillary tubes. The cleaning was more effective with cyclic VC than UC cleaning at given conditions. Raising the temperature, of the liquid increased cavitation and caused better wetting of the carbon black powder at the bottom of the tubes. The optimized VC process parameters (25 vacuum cycles, 1% SLS in DI water, vigorous stirring at 40 °C) removed 99 ± 1% of the carbon black powder. This study showed experimental evidence that cyclic VC is a good cleaning approach for cleaning parts that have deep blind holes.
... However, one anionic surfactant called sodium lauryl sulfate (SLS), technically known as sodium dodecyl sulfate (SDS) (CAS No. 151-21-3), is rarely monitored and remains unregulated as it is deemed "environmentally-friendly" due to its biodegradable nature [13]. Another pressing issue surrounding this anionic surfactant is the lack of a scientific consensus. ...
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Due to its ubiquitous presence in the environment and the lack of a scientific consensus regarding the environmental safety of the widely used anionic surfactant Sodium Lauryl Sulfate (CAS No: 151-21-3), a systematic literature review and thematic analysis was conducted. All studies about sodium lauryl sulfate (SLS) in the environment in key databases were reviewed, with coding methods used to identify impact categories from SLS exposure without potential narration bias. Based on the limited number of studies on SLS, there is empirical evidence of this surfactant contributing to environmental toxicity at various concentrations (0.004–3509 mg L-1), with aquatic organisms at a higher risk from exposure. Furthermore, exposure to SLS can elicit changes to various organismic processes and environmental equilibrium. Hence, further study on SLS in various environmental compartments is recommended to monitor the level of SLS pollution, understand its behavior upon contact with various environmental media, and understand its impacts on flora and fauna. Lastly, SLS quantification should be done on commonly used consumer products to potentially regulate its use and to consequently curb SLS pollution from its source.
... Foaming Agent Sodium lauryl sulfate is an anionic surfactant frequently used in household cleaning products as an emulsifying cleaning agent (Bondi et al., 2015). Methyl Paraben 0.3 Preservative Methylparaben is used as a food preservative as well as an anti-fungal agent. ...
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The scientific study linked to the physical, chemical, biological, and structural characterization of drugs along with their history of cultivation, collection and preparation for marketing and preservation, is defined as pharmacognosy. The cardinal routes of the entry of various infections into our body are our hands. The infection caused thereby causes a spectrum of diseases, especially in children. To get rid of such infections, regular washing of hands after specific time intervals holds imperative cognizance of getting rid of such infectious diseases. The handwash available in the local markets is mainly composed of various chemical compounds which might pose several threats to our skin. In this notion, the search for alternate components for handwash preparation that are organic in nature and do not cause any damage to our skin has been in the research limelight for the past few years. Accordingly, in this research, an attempt has been made to prepare a skin-friendly handwash containing the essential extracts of various ingredients like Aloe vera, turmeric, honey, tulsi, lemon, etc., and thereby their antimicrobial and antiseptic efficacy were evaluated. The basis of the evaluation was set using multivariate criteria like odour, colour, viscosity, pH, foam height and retention, and grittiness. Finally, the skin irritation test was also carried out along with a few other parameters to draw conclusions regarding the suitability of the handwash for human usage. The obtained results were found within the desired ranges without the presence of any adverse side effects. Thus, the proposed scheme of this study may be regarded as an excellent approach to combat the harmful effects of commercial chemicals containing handwash and, thereby, will be beneficial to various stakeholders.
... In developing countries, household substances and insecticides are the common causes of poisoning [3]. Acute pediatric poisoning especially with household products remains a worldwide health issue that requires medical attention in hospital emergency departments with consequences such morbidity and mortality [4][5][6]. ...
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Background Several studies worldwide have investigated household product poisoning. We conducted a toxico-clinical study on the two-year prevalence of poisoning with household products. Methods This cross-sectional study was performed in Khorshid Hospital, the main referral center for poisoning cases in Isfahan, affiliated to Isfahan University of Medical Sciences, Isfahan, central Iran. All patients with intentional or unintentional household substance poisoning, referring to the poisoning emergency center of the hospital, were evaluated with respect to epidemiological and toxico-clinical features and outcomes. Results During the study period, 5946 patients were hospitalized, of which 83 (1.39%) had been poisoned with household products including 48 (57.8%) men and 35 (42.2%) women with a mean ± SD age of 34.40 ± 17.71 years. Most patients (54.2%) were in the 20–40-year-old age group. Accidental poisoning (63.9%) was the most common type of exposure ( P = 0.02) predominantly in men (57.8%, P = 0.51). The most common household products were sodium hypochlorite (32.53%) followed by petroleum hydrocarbon (21.68%). Most of the accidental poisonings (77.8%) were due to petroleum hydrocarbon. 59% of cases were poisoned at home ( P < 0.0001). No patient died. Conclusion Household products were not common means of poisoning in our referral center. Sodium hypochlorite and petroleum hydrocarbon were the most common substances. Most of the patients were men with accidental exposure at home. Because of the availability of the household product, the frequency and outcomes may be varied in different societies.
... Electrodialysis has a complex device, high power consumption, high maintenance intensity, and strict technical requirements for operators [22]. High-priced metal ions in the water can also easily cause membrane poisoning and damage to electrodes [23,24]. Several studies on fluoride removal technology have used simulated fluorine-containing solutions prepared in the laboratory, which have fewer impurities and are quite different from natural water bodies [25,26]. ...
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The typical lime precipitation method is used to treat high-concentration fluorine-containing wastewater. In this way, the fluorine in the wastewater can be removed in the form of CaF2. Thus, this method has a good fluoride removal effect. In this study, calcium hydroxide was used to adjust the pH and achieve a significant fluoride removal effect at the same time. The removal rate of fluoride ion decreases gradually with the increase in the concentration of sulphate in the raw water. When the synergistic defluorination cannot meet the requirements of water production, adding a step of aluminium salt flocculation and precipitation can further reduce the fluoride ion concentration. According to the feasibility of the actual project, this study improves the lime coagulation precipitation defluorination process on this basis, and the combined process is synchronised. In the process optimisation, barium chloride is added to remove the influence of sulphate radicals in the water, and then, the pH is adjusted to 5–6. The fluoride ion concentration in high-salt wastewater can be reduced from 446.6 mg/L to 35.4 mg/L by defluorination after pre-treatment whose removal rate was 92.1%. The combined process synchronously removes fluorine and purifies the water quality to a certain extent. Indicators such as COD, total phosphorus, ammonia nitrogen, and chloride ions in wastewater are reduced, and the removal rate is increased by 35.5% under the same conditions. This scheme improves the wastewater treatment effect without increasing the existing treatment equipment. Thus, it achieves a better defluorination effect and reduces the dosage of chemicals as much as possible, which is conducive to lowering the discharge of sludge after treatment.
... All the values for sulphate in synthetic hairs fell below the FEPA [17] permissible limits of 200 mg/l for sulphate in synthetic hairs. Exposure to sulphate in the body have been associated with reduced lung function, aggravated asthmatic symptoms, increased risk of emergency department visits, hospitalizations, and death in people with chronic heart or lung diseases [9]. ...
The main objective of this research was to develop a liquid foaming agent for optimizing gas production in wells belonging to the Santa Rosa field in Área Mayor de Anaco, Venezuela. In this research, three liquid foaming agent formulations were developed with an anionic and amphoteric surfactants mixture, performing tests to evaluate foaming and lifetime on samples with different produced water/hydrocarbon condensate ratios. A liquid drag test was also carried out, explaining the liquid recovery performance after applying the developed formulations at different dosages and finally evaluated products results were compared with a commercial one. Formulation 1 obtained a higher liquid recovery compared to the other formulations, in addition, recovered liquid amount in dynamic drag tests decreased as the condensates composition increased in four samples evaluated. Formulation 1 and commercial product used as a reference did not have statistically significant differences.
Some conventional sanitizers and antibiotics used in food industry may be of concerns due to generation of toxic byproducts, impact on the environment, and the emergence of antibiotic resistance bacteria. Bio-based antimicrobials can be an alternative to conventional sanitizers since they are produced from renewable resources, and the bacterial resistance to these compounds is of less concern than those of currently used antibiotics. Among the bio-based antimicrobial compounds, those produced via either fermentation or chemical synthesis by covalently or electrovalently attaching specific moieties to the fatty acid have drawn attention in recent years. Disaccharide, arginine, vitamin B1, and phenolics are linked to fatty acids resulting in the production of sophorolipid, lauric arginate ethyl ester, thiamin dilauryl sulfate, and phenolic branched-chain fatty acid, respectively, all of which are reported to exhibit antimicrobial activity by targeting the cell membrane of the bacteria. Also, studies that applied these compounds as food preservatives by combining them with other compounds or treatments have been reviewed regarding extending the shelf life and inactivating foodborne pathogens of foods and food products. In addition, the phenolic branched-chain fatty acids, which are relatively new compounds compared to the others, are highlighted in this review.
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There is no direct evidence supporting that SDS is a carcinogen, so to investigate this fact, we used HaCaT keratinocytes as a model of human epidermal cells. To reveal the candidate proteins and/or pathways characterizing the SDS impact on HaCaT, we proposed comparative proteoinformatics pipeline. For protein extraction, the performance of two sample preparation protocols was assessed: 0.2% SDS-based solubilization combined with the 1DE-gel concentration (Protocol 1) and osmotic shock (Protocol 2). As a result, in SDS-exposed HaCaT cells, Protocol 1 revealed 54 differentially expressed proteins (DEPs) involved in the disease of cellular proliferation (DOID:14566), whereas Protocol 2 found 45 DEPs of the same disease ID. The ‘skin cancer’ term was a single significant COSMIC term for Protocol 1 DEPs, including those involved in double-strand break repair pathway (BIR, GO:0000727). Considerable upregulation of BIR-associated proteins MCM3, MCM6, and MCM7 was detected. The eightfold increase in MCM6 level was verified by reverse transcription qPCR. Thus, Protocol 1 demonstrated high effectiveness in terms of the total number and sensitivity of MS identifications in HaCaT cell line proteomic analysis. The utility of Protocol 1 was confirmed by the revealed upregulation of cancer-associated MCM6 in HaCaT keratinocytes induced by non-toxic concentration of SDS. Data are available via ProteomeXchange with identifier PXD035202.
This work primarily emphases on evaluating the prevalence of organic micropollutants (OMPs) in the perennial Yamuna River (YR) that flow through the national capital of India, Delhi. Sixteen sampling campaigns (non-monsoon, n = 9; monsoon n = 7) were organized to understand the seasonal variations with special emphasis on monsoon. We have found fifty-five OMPs in the monsoon; while forty-seven were detected in non-monsoon. Fifty-seven screened and quantified OMPs in the most polluted stretch of River Yamuna included the pharmaceutically active compounds, pesticides, endocrine-disrupting chemicals, phthalates, personal care products, fatty acids, food additives, hormones, and trace organics present in hospital wastes. During monsoon months, compounds for which concentrations exceeded 50 μg/L were: adenine (64.6 μg/L), diethyl phthalate (62.9 μg/L), and octamethyltrisiloxane (56.9 μg/L); and the same for non-monsoon months was only for 1-dodecanethiol (52.3 μg/L). The average concentration of OMPs in non-monsoon months indicate PhACs>PCPs>Pesticides>Fatty acids>Hospital waste>Hormones>Pesticides>EDCs. In monsoon months due to surface runoff and high volume of untreated wastewater discharges few more OMPs concentrations were detected which mainly includes PhACs (clofibric acid, diclofenac sodium, gemfibrozil, ketoprofen), pesticides (aldrin, metribuzin, atrazine, simazine). Due to dilution effect in the monsoon months, average concentrations of 3-acetamido-5-bromobenzoic acid (PhACs) was reduced from 45.22 μg/L to 14.07 μg/L, whereas some EDCs such as 2,4- Di-tert-amylphenol, 3,5- di-tert-butyl-4-hydroxybenzyl alcohol, Triphenylphosphine oxide, Benzophenone were found in much higher concentrations in the monsoon months. Octamethyltrisiloxane (PCPs) was detected 50 times higher in concentration in the monsoon months. Interestingly, the concentration of about 50 % of the OMPs was more in the monsoon samples than in non-monsoon samples which is contrary to the general understanding that monsoon-induced dilution lowers the concentrations of OMPs. In RY water higher magnitude of diclofenac sodium, ibuprofen, ketoprofen, and clofibric acid was found than Europe and North America rivers. Hormones such as estriol and estrone in RY water are found 70 to 100 times higher than the maximum reported concentrations in the US streams.
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BACKGROUND: The effect of different shampoo formulations as a risk factor for cataract formation was investigated in Sprague Dawley rats in the present study. METHODS: Study was performed by using 20 rats. Two different shampoos used by adult subjects and two different baby shampoos were used in the study. Different shampoos were used in different groups for 14 days, and they were followed for changes. RESULTS: Different degree of opacities were observed in 4 (40%), 4 (40%), 5 (50%), and 6 (60%) eyes in Groups A, B, C, and D, respectively. There was no statistically significant difference for formation of cataract between the groups (p>0.05). The number of irritated eyes was significantly lower (p<0.05) in groups C (10%) and D (20%) compared to groups A (90%) and B (80%). CONCLUSION: The use of non-irritant baby shampoos does not seem to eliminate the risk of cataract formation and these should even be used more carefully as the non-irritant shampoo will have more contact with the eye. [TAF Prev Med Bull. 2008; 7(1): 1-6]
Synthetic detergents are reported to be acutely toxic to fish in concentrations between 0.4 and 40 mg/1. Factors affecting toxicity include the molecular structure of the detergent, water hardness, temperature and dissolved oxygen concentration; the age and species of the test fish, and acclimation to low concentrations of detergent. Some of these factors appear to be of only limited importance. Gill damage is the most obvious acute toxic effect; the immediate cause of death may be asphyxiation, but detergents may also be toxic internally. Lethal effects not related to gill damage have not been investigated. Sublethal effects include retardation of growth, alteration of feeding behaviour and inhibition of chemoreceptor organs. Low levels of detergents may also increase the uptake of other pollutants. Invertebrates, especially in their juvenile stages, are extremely sensitive to detergents: concentrations below 0.1 mg/1 interfere with growth and development in some species. The interactions between detergents and proteins, and their influence on membrane permeability may be the basis of the biological action of detergents. Detergents in natural waters are usually partially degraded, and a maximum permissible concentration of 0.5 mg/1 would probably be harmless under most conditions.
A headspace, gas chromatography-mass spectrometric (GC-MS) method for the identification and quantitation of 1,4-dioxane in polyethoxylated surfactants is described. An isotope dilution method employing 1,4-d8-dioxane has been used for the quantitation of 1,4-dioxane which is based on the determination of the molecular ion (mass 88) by MS. The detection limit of the method was 0.3 ppm 1,4-dioxane. 82% of the cosmetic products investigated were found to contain 0.3–96 ppm 1,4-dioxane, and 85% of the products for dish washing investigated contained 1.8–65 ppm 1,4-dioxane.
Surfactants are one of the major components (10–18%) of detergent and household cleaning products and are used in high volumes. Several are commonly found in natural waters and consequently, their impact on the environment has been, and continues to be, discussed in the U.S.A., Western Europe and Japan. The chronic and sublethal toxicities of commercially important surfactants to aquatic animal life have not been summarized in the available scientific literature. Based on the summary provided here scientific understanding of the chronic and sublethal toxicities of cationic surfactants is less than that for the other surfactant groups. Chronic toxicity of anionic and nonionic surfactants occurs at concentrations usually greater than 0.1 mg/l. Effects of these same surfactants on several behavioral and physiological parameters range from 0.002 to 40.0 mg/l. The available toxicity data base is largely comprised of laboratory-derived toxicity data for a few surfactants, predominantly LAS, and single freshwater planktonic species such as Daphnia magna and the fathead minnow and a benthic midge. Community effect levels have been reported only for linear alkylbenzene sulfonate (LAS) and effects on single freshwater and saltwater test species and on natural biotic communities are largely unknown for many commercially important surfactants. Based on a comparison of the reported chronic toxicity data and measured environmental levels in rivers, the aquatic safety of the anionic LAS is indicated, more so than for any other surfactant. Safety assessments for other major surfactants in saltwater and freshwater should be considered preliminary and limited until validated with corresponding exposure measurements and additional laboratory and field-derived chronic toxicity data for animal test species.
The effects of several environmental modifying factors on surfactant toxicity have been reported in the scientific literature during the past 40 years. The results from 58 reports describing, among other factors, the effects of mixtures, hardness and temperature are summarized in this report. The most common test compound used in the reviewed studies was the anionic linear alkylbenzene sulfonate. Most tests have been conducted in the laboratory with single species of freshwater fish, but a few studies have been conducted in ponds, lakes and rivers with natural biotic assemblages. Of the 58 reports reviewed, those describing the toxicities of mixtures containing surfactants are the most numerous (n = 32). The impact of the presence of pesticides and metals on surfactant toxicity has been unpredictable but oil-surfactant mixtures are usually more toxic than expected. Increasing water hardness and temperature increases surfactant toxicity in some cases but the outcome has been compound and species-specific. The presence of suspended solids and naturally occurring dissolved substances decreases the bioavailability of cationic surfactants but not that of anionic and nonionic surfactants. The impact of other chemical and physical modifying factors on surfactant toxicity are too poorly understood to generalize. Therefore, additional research is needed to determine these effects particularly on the chronic toxicities of surfactants at the multispecies level. These data are necessary if environmental hazard assessments for most surfactants are to go beyond their current simplification and be more effective in predicting ecological risk.
Introduction to surfactant biodegradation. What is biodegradation? Biodegradability testing. Testing strategy and legal requirements. Biodegradability of anionic surfactants. Biodegradabilty of cationic surfactants. Biodegradability of non-ionic surfactants. Biodegradability of amphoteric surfactants. Index.
Irritant reactions were induced on the forearms of 10 normal subjects with 10% aqueous sodium lauryl sulfate under patch test occlusion for 24 h. Test sites were observed at 24, 26, 28, 30, 48, 72 and 96 h and the degree of inflammation recorded. Inflammation was most prominent at 28 h and decreased in intensity over the time course of the study. Inflammation at 48 and 72 h was similar to when patches were removed. This suggests that inflammatory responses in skin for at least certain irritants like sodium lauryl sulfate do slowly decrease in intensity after 48 h. However, the inflammatory response may initially accelerate after patch test removal and remain intense for at least 48 h. Fading of irritant reactions by 48 or 72 h may not reliably distinguish irritant from allergic patch test reactions. This does not refute the usefulness of a delayed (96 h) reading since inflammation from sodium lauryl sulfate had decreased significantly by this time.