This paper quantifies diaper exposure factors: body weight, changes per day, direct lotion transfer, and rewet. It does not report metal concentrations. The worked example is residual acrylic acid in superabsorbent polymer. Age-band body weights reprinted from US EPA and urine volumes adapted from Goellner et al. 1981 were not re-extracted row by row. The 7 percent direct-transfer default recommended by Rai et al. 2009 is cited and was not entered as the authors’ adopted factor; their Table 10 uses 4 percent.
Key numbers
| Analyte | Matrix | Value | Unit | Statistic | N | Where |
|---|---|---|---|---|---|---|
| acrylic acid | oral reference dose | 0.5 | mg/kg/day | RfD | Table 11 p.9 (printed 191) |
Methods (brief)
Authors adopt 8 kg for exposure calculations. Diary overall mean is 4.7 diapers per day (75th 5.0, 90th 6.0, 95th 7.0). Direct lotion transfer was 3.0 to 4.3 percent. Rewet at half the contact area ranged from 0.32 to 0.66 percent, mean 0.46 percent. Acrylic acid systemic exposure in the example is 0.011 mg/kg/day with a cited EPA RfD of 0.5 mg/kg/day and a margin of safety of 45.
Detection and reporting: acrylic acid LOQ 10 mg/diaper; collagen extracts were below quantitation
Basis: diaper as used; systemic dose per kg body weight
Evidence fitness
This source can support: diaper use frequency; skin transfer and rewet fractions for exposure models; an acrylic acid exposure example.
It cannot support: metal content of diapers or diaper cream; zinc oxide exposure.
Limitations
No metals. Table 11 prints both 500 ppm and a formula line that says 500 mg/g; both strings are copied and not reconciled. Lotion-transfer methods are described as previously published by Odio et al. 2000. Product brand names are not used.
Related evidence
Update history
No substantive edit history is available in this build. The full commit record is available in git.