# Executive Summary of EPA 747-R-96-012

Conversion Equations for Use in Section 403 Rulemaking

December, 1997 (EPA 747-R-96-012)

EXECUTIVE SUMMARY

1. WHAT DOES THIS REPORT SAY?

This report presents equations used to carry out various conversions between wipe lead loading and vacuum lead loading, based on two different vacuum samplers, the Blue Nozzle vacuum (BN) used in the HUD National Survey, and the modified HVS3 vacuum used in the Baltimore Repair and Maintenance Study. The modified HVS3 vacuum will be referred to as the BRM vacuum for the remainder of this report.

Uncarpeted floors:

Homes Built Prior to 1940: Wipe = 5.66 BN0.809

Homes Built 1940-1959: Wipe = 4.78 BN0.800

Homes Built 1960-1979: Wipe = 4.03 BN0.707

Window sills: Wipe = 2.95 BN1.18

Window wells: Wipe = 5.71 BN0.864

Uncarpeted floors: BN = 0.185 Wipe0.931

Window sills: BN = 0.955 Wipe0.583

Window wells: BN = 4.91 Wipe0.449

Applying the first of the above equations, for example, a wipe lead loading of 100 µg/ft2 on an uncarpeted floor would be converted to a BN lead loading of 13.5 µg/ft2. It has an approximate 95% confidence interval of 9.47 to 19.0 µg/ft2. The 95% prediction interval is 1.912 to 94.3 µg/ft2.

For samples collected with the BRM vacuum sampler, from uncarpeted floors, carpeted floors, window sills, and window wells, the following equations were developed for converting a BRM lead loading (µg/ft²) to a wipe lead loading (µg/ft²):

Uncarpeted floors: Wipe = 8.34 BRM0.371

Carpeted floors: Wipe = 3.01 BRM0.227

Window sills: Wipe = 14.8 BRM0.453

Window wells: Wipe = 13.9 BRM0.630

For example, a BRM lead loading of 100 µg/ft² on an uncarpeted floor would be converted to a wipe lead loading of 46.0 µg/ft² by applying the first equation. An approximate 95% confidence interval for this prediction is 40.5 to 52.3 µg/ft². The 95% prediction interval of the wipe loadings associated with a BRM loading of 100 µg/ft² is 5.9 to 262 µg/ft².

2. WHY WERE THESE EQUATIONS DEVELOPED?

3. HOW LARGE IS THE UNCERTAINTY ASSOCIATED WITH THESE CONVERSION EQUATIONS?