1. Literature review:
• Reviewed dermal absorption journal articles and model documentation.
• Goal: Identify substance properties and exposure scenarios controlling dermal absorption.
Model development:
• Developed framework to calculate dermal uptake of substances from a particular product
called Product Intake Fraction (PiF), which parallels the existing LCA matrix framework.
• Developed framework to calculate direct impacts of substances from three products: a
pacifier, hand soap, and shampoo.
• Defined each product’s functional unit as 1 day of normal use.
Data collection:
Direct exposure -
• Compiled product composition data from ConsExpo (RIVM 2010), an exposure assessment
model.
• Compiled substance physicochemical properties from USEtox (Rosenbaum et al. 2008), a
consensus LCA model.
• Used dose response data and severity factors from IMPACT 2002+ (Jolliet et al. 2003).
• Measured parameters for: pacifier (mass of mouthing piece), hand soap (mass of soap and
water to wash hands), and shampoo (mass of shampoo and water to wash hair).
Indirect exposure -
• Compiled primary and secondary PM2.5 emission rates from IMPACT 2002+ (for pacifier).
• Used PM2.5 characterization factor data from Humbert et al. (2011) (for pacifier).
• Adapted pre-calculated indirect life cycle impact results from Koehler et al. (2009) (for
soap and shampoo).
Analysis:
• Compared skin permeability coefficient equations.
• Calculated direct product impacts based on newly developed framework.
• Calculated indirect product life cycle impacts based on model development and
conversion data from IMPACT 2002+.
• Compared direct vs. indirect impact for each product.
METHODS
Motivation:
Life Cycle Assessment (LCA) is a tool to evaluate the environmental impact (to
human health and ecosystems) of a product throughout its life cycle stages. Current LCA
approaches calculate exposure through environmental emissions leading to inhalation
and ingestion, BUT dermal contact, e.g., from consumer products, is not covered.
Existing risk models estimate dose from dermally applied products, but there is little
information regarding product impacts on human health.
Methods:
Equations linking chemical properties to dermal uptake to human health impacts of
a chemical substance from two product types were developed based on a literature
review and a comparison of skin permeability models. Potential dermal uptake of several
substances in three products was calculated. In addition, indirect impacts from life cycle
emissions were calculated.
Results:
Direct impact from the products was of the same magnitude as or higher than
indirect life cycle impacts. The development of this approach and these results are the
first advancement towards introducing dermal exposure into life cycle assessment.
METHODS
Products & Substances Used in
Data Collection & Analysis
Dermal Exposure for Life Cycle Impact Assessment
Susie Chung1, Andrew Henderson2, Shanna Shaked2, Professor Olivier Jolliet2
(1) U. of Michigan, Dept. of Civil & Environmental Engineering, (2) U. of Michigan, School of Public Health,
Dept. of Environmental Health SciencesABSTRACT
RESULTS: Skin Permeability Models
• Developed equation for the Product Intake Fraction (PiF), the fraction of a substance
dermally absorbed. Important variables: leach rate and skin permeability coefficient
(Kp).
RESULTS: Impact
• A method to calculate direct impact for a pacifier, hand soap, and shampoo was developed.
• To calculate dose response for direct impacts, ED50 values were required. These were extrapolated
from oral LD50s, except for Limonene’s value, which was available in USEtox (Rosenbaum et al. 2008).
RESULTS: Product Intake Fraction
• Leach rate = rate of amount of
substance released from pacifier
• Kp = rate that substance is
absorbed by the skin
• I = Impact on human health • U = Substance uptake through skin • DALYs = Disability Adjusted Life
• SF = Severity factor • DR = Dose response of population Years = # yrs. lost due to disability
• ED50 = the effect dose to the substance and premature death
required for half the • LD50 = the lethal dose required • EV = extrapolation value = 26
population to show an effect for half the population to die (Rosenbaum et al. 2011)
RESULTS: Impact Calculations
• Direct impacts are of the same magnitude as or higher than indirect life cycle impacts.
• Indirect shampoo impact was not available in the literature. Based on expert judgment,
indirect soap impacts were taken as a proxy (indicated in light red).
CONCLUSIONS & FUTURE RESEARCH
• Based on the equations developed for dermal uptake and impact, direct dermal exposure is an
important pathway to consider when conducting LCA work on consumer products.
• LCAs on shampoo and other dermally applied products are needed for direct-indirect impact
comparison.
• Unlike some LCA models’existing pathways (inhalation, ingestion) that begin with the substance‘s
emission compartment, dermal exposure begins with the product and its use.
• This work shows that it will be important for future LCA models to implement dermal exposure as
a pathway into their frameworks, possibly with the addition of a dermal products matrix.






⋅÷





=





kg
mg
kg
lifetime
EV
kg
mg
LD50
lifetime
kg
ED50
animalanimal
substance
Substances
(CAS #)
Di-Isononyl
Phthalate
(DINP)
(28553-12-0)
Sodium
Lauryl Ether
Sulfate
(SLES)
(9004-82-4)
Linalool
(78-70-6)
Limonene
(5989-27-5)
Benzyl
Benzoate
(120-51-4)
DMDM
Hydantoin
(6440-58-0)
Use Plasticizer Surfactant
(Cleaning
Agent)
Fragrance Fragrance Stabilizer Preservative
Products
Pacifier 
Hand Soap 
Shampoo     
• Products and substances were selected based on available existing data.
• Kp is a controlling parameter in dermal absorption of substances.
• Six Kp models were compared with varying Kow and molecular weight (MW): variation in
Kow is a key factor in determining Kp.
• Pending further analysis, geometric means of the models' Kp predictions for sample sub-
stances were used.
References
Fiserova-Bergerova et al., 1990, Am. J. Ind. Med., 17(5), 617-635.
Guy et al., 1992, J. Pharm. Sci., 81(6), 603-604.
Humbert et al., accepted 2011, Environ. Sci. Technol., DOI:
10.1021/es103563z.
Jolliet et al., 2003, Int. J. LCA, 8(6), 324-330.
Koehler et al., 2009, Environ. Sci. Technol., 43(22), 8643-8651.
Konemann, ed., 1998, Dutch Natl. Inst. Public Health and Environ.
(RIVM), Report #613320002.
McKone, 1993, Lawrence Livermore Natl. Lab., Report
#UCRL-CR-111456.
McKone et al., 1992, Risk Anal., 12(4), 543-557.
RIVM, 2010, ConsExpo,
http://www.rivm.nl/en/healthanddisease/
productsafety/ConsExpo.jsp#tcm:13-42840, accessed
June 12, 2011.
Rosenbaum et al., 2008, Int. J. LCA, 13(7), 532-546.
Rosenbaum et al., accepted 2011, Int. J. LCA, DOI: 10.1007/s11367-011-
0316-4.
Wilschut et al., 1995, Chemosphere, 30(7), 1275-1296.
unitfunctional
DALYs
cases
DALYs
kg
cases
kg
kg
unitfunctional
kg
SFDRiFSI
unitfunctional
DALYs
cases
DALYs
kg
cases
kg
kg
unitfunctional
kg
SFDRPiFUI
intakeemit
intakeemit
indirectPM2.5pacifier,
intakeproductin
intakeproductin
directhampoo,pacifier/s
=×××=
×××=
=×××=
×××=
1E-13
1E-12
1E-11
1E-10
1E-09
1E-08
1E-07
1E-06
1E-05
1E-04
1E-03
pacifier
(DINP)
soap (SLES) shampoo
(SLES)
shampoo
(DMDM
Hydantoin)
shampoo
(linalool)
shampoo
(limonene)
shampoo
(benzyl
benzoate)
DALYs/functionalunit
ImpactComparison
direct
indirect
1E-09
1E-08
1E-07
1E-06
1E-05
1E-04
1E-03
1E-02
1E-01
1E+00
1E+01
1E+02
1E+03
1E+04
1E+05
1E+06
1E+07
1E+08
1E-04 1E-01 1E+02 1E+05 1E+08 1E+11
SkinPermeabilityCoefficient(Kp)
Octanol-WaterPartition Coefficient (Kow)
Skin Permeability - Octanol-Water Partition Coefficients
McKone, 1993, model 1, MW=50
McKone, 1993, model 1, MW=500
McKone, 1993, model 2, MW=50
McKone, 1993, model 2, MW=500
McKone et al., 1992, model 3, MW=50
McKone et al., 1992, model 3, MW=500
Fiserova-Bergerovaet al., 1992, model 4, MW=50
Fiserova-Bergerovaet al., 1992, model 4, MW=500
Guy et al., 1992, model 5, MW=50
Guy et al., 1992, model 5, MW=500
Wilschut et al., 1995, model 6, MW=50
Wilschut et al., 1995, model 6, MW=500
SLES
DMDM Hydantoin
Linalool
Limonene
Benzyl Benzoate
DINP
[ ]
[ ]
[ ]−=−=−=
−=
⋅−⋅
⋅
⋅⋅⋅
=
⋅⋅
⋅⋅⋅
=
⋅−⋅− hr
cm
hrcmtime
thicknessproduct
Kp
napplicatiodirect
6
rplasticize
2
2
pacifier
mouthinpacifier
mouthing
e1e1PiF
g
μg
10fg
mincm
μg
cm
d
min
d
factorconversionrplasticizefractionweight
rateleachareadayperdurationexposurelifetime
PiF
exposed