Appendix 2

Estimated surface area of paint containing 15 ug of bioavailable lead (square inches)

Pb in paint (%) Pb in paint (ug/g)   Bioavailability      
    5% 10% 20% 30% 40%
0.02 200 35.778 17.889 8.945 5.963 4.472
0.06 600 11.926 5.963 2.982 1.988 1.491
0.50 5000 1.431 0.716 0.358 0.239 0.179
0.87 8670 0.825 0.413 0.206 0.138 0.103
1.47 14740 0.485 0.243 0.121 0.081 0.061
10.00 100000 0.072 0.036 0.018 0.012 0.009
29.00 290000 0.025 0.012 0.006 0.004 0.003

(15 ug Pb X 1000000 ug/g) / (ug Pb/g paint X ug paint/cm2 paint X bioavail X 6.45 cm2/in2) = in2 paint

0.06% CPSC Pb in paint allowable maximum, Code of Federal Regulations Title 16 Part 1303; 0.50% HUD Pb in paint action level, HUD (1995)- "Guidelines for the evaluation and control of lead-based paint hazards in housing."

0.87% median Pb in old playground equipment paint samples by CPSC

1.47% median Pb in old playground equipment paint above 0.5% in samples by CPSC

29% maximum Pb in playground equipment paint reported to CPSC

Bioavailability from CPSC (1990) and mild acid extractions of playground equipment paint tested by CPSC staff.

Chronic Pb ingestion from paint and other consumer products should not exceed 15 ug Pb/day (CPSC, 1990). CPSC staff consider about 15-30 days as a surrogate for chronic ingestion.

1 coat of old paint weighs 6500 ug/cm2/coat (King, 1971)

A child could ingest 1.32 in2 (8.5 cm2) of paint as chips and dust (NAS, 1973)

References:

CPSC (1990)- "Revision of the CPSC 0.06% lead in paint standard". Memo from BC Lee to SC Eberle. 22 June.

BG King (1971)- "Maximum daily intake of lead without excessive body lead-burden in children." Amer J Diseases Child 122: 337-340.

NAS, Natl Academy of Sciences (1973)- "Report of the ad hoc committee to evaluate the hazard of lead in paint."