Appendix D Food Codes for NHANES - OEHHA

Scientific Review Panel Draft February, 2012
F. 3.8.2 Discussion and Recommendation for a Nickel and Nickel Compound
ABS
The only study that exposed human skin to soil contaminated with a nickel salt
was the in vitro study by Moody et al. (Moody et al., 2009b). However, there is
evidence to suggest in vitro tests for dermal absorption of nickel may
underestimate absorption in vivo.
Hostynek et al. (2001a) observed a range of 26.1% to 3.3% absorption of applied
dose over 24 hrs among four nickel salts tested in vivo on human stratum
corneum. However, Tanojo et al. (2001) observed only a range of 1.65% to
0.12% absorption of applied dose over 96 hrs among the same four nickel salts
tested in vitro on human stratum corneum. Comparison of these data indicates
that reliance on in vitro absorption data probably underestimates the in vivo
dermal absorption of nickel salts.
Specifically regarding the nickel chloride salt applied directly to skin, Hostynek et
al. (2001a) observed a 24-hr total absorption of 3.3% for human skin in vivo,
while Tanojo et al. (2001) observed a 96-hr total absorption of 0.92% for human
skin in vitro. These data together suggests a 3.6-fold greater absorption in vivo
compared to in vitro absorption.
Although the dermal absorption time used by Tanojo et al. (2001) was 96 hrs,
most of the NiCl2 had penetrated the skin in the first 24 hrs (probably greater
than 95%) and appearance of nickel into the diffusion cells had attained steady
state. Assuming steady state levels of NiCl2 had also been reached in stratum
corneum by 24 hrs, it can be estimated that the total absorption of NiCl2 recorded
by Tanojo et al. at 96 hrs was similar to that found at 24 hrs.
Applying a 3.6-fold in vivo/in vitro ratio adjustment to the fractional dermal
absorption value of 1% for NiCl2 determined by Moody et al. (2009b) results in an
ABS value of 3.6% (or 4% when rounded to the nearest whole number). The
ABS is similar to the fractional dermal absorption of 2-4% resulting from
exposure of pig skin to NiCl2 aged in different soils (Abdel-Rahman et al., 1997;
Abdel-Rahman et al., 1999).
F. 3.9 Selenium and Selenium Compounds
Recommended use of default inorganic compound ABS estimate of 13.0%.
F. 3.9.1 Studies Considered
No quantitative data could be found regarding the fractional dermal absorption of
soil-bound selenium (Se) or Se compounds applied to skin.
F-44