Appendix D Food Codes for NHANES - OEHHA

Scientific Review Panel Draft February, 2012
Another limitation includes reliance on studies in which Cr(VI) is applied directly
onto the skin (i.e., neat), rather than combined with soil, for estimation of
fractional dermal absorption. Kissel (2011) has reported that fractional
absorption is dependent on skin loading conditions for application of organic
chemicals directly to skin. Increased skin loading of an organic chemical will
result in lower fractional absorption provided complete coverage of the skin at the
site of application occurs. Using PVC film as a surrogate for soil for transfer of
DEHP from the film to skin is used in the estimation of the ABS, and thus
reduces potential mismeasure of dermal absorption of organic compounds
applied neat.
Other limitations include No no data for dermal absorption of the compound
bound to soil was located in the literature. In addition, no oral bioavailability
studies for DEHP bound to soil could be found. Thus, no further adjustment of
the ABS for absorption from a soil was applied.
F. 4.7 Dermal Absorption Fraction for 4,4’ –Methylenedianiline
Recommended use of default organic compound ABS estimate of 10%.
F.4.7.1 Studies Considered
Brunmark et al. (1995) utilized a patch-test method to evaluate dermal exposure
and pharmacokinetics of 4,4’-methylene dianiline (MDA) dissolved in
isopropanol. Measurements of MDA were made in plasma and urine of the five
human volunteers. The extent of absorption was evaluated by measuring the
amount remaining in the patch after 1 hour. Determination of MDA remaining in
the patch showed 25 to 29% was absorbed. The authors also describe
elimination half-lives from plasma and urine.
Workers were monitored for two consecutive weeks in a fiber glass pipe factory
for dermal exposure to MDA (diluted with triethyleneamine) using both cotton
glove and hand wash monitoring (Brouwer et al., 1998). Urinary excretion of
methylene dianiline was also evaluated. Urinary MDA levels correlated well with
exposure measurements. Geometric means of daily exposure ranged from 81 to
1783 µg MDA, while 24 hour urine samples ranged from 8 to 249 µg MDA.
Given that the Brunmark study identified a urinary half-life of MDA of 7 hours and
that the measurements on the hands and forearms of the workers correlated
strongly (0.94) with the urinary excretion of MDA, one can roughly estimate that
between 10 and 14% of the MDA on the hands and forearms was absorbed by
the workers.
MDA was applied in vitro to unoccluded human and rat skin for 72 hrs at a
loading of 17.7-40.6 µg/cm 2 in ethanol (Hotchkiss et al., 1993). Absorption into
the receptor fluid at 72 hrs was 6.1 and 13.0% of the applied dose for rat and
F-66
Comment [DD1]: Should say DEHP