Proposal for the assessment to quantitative dermal exposure limits in occupational environments: Part 2. Feasibility study for application in an exposure scenario for MDA by two different dermal exposure sampling methods.

Abstract

Objective-To evaluate two diVerent techniques for assessing dermal exposure to 4,4'-methylene dianiline (MDA) in a field study. The results were used to test the applicability of a recently proposed quantitative dermal occupational exposure limit (DOEL) for MDA in a workplace scenario. Methods-For two consecutive weeks six workers were monitored for exposure to MDA in a factory that made glass fibre reinforced resin pipes. Dermal exposure of the hands and forearms was assessed during week 1 by a surrogate skin technique (cotton monitoring gloves) and during week 2 by a removal technique (hand wash). As well as the dermal exposure sampling, biological monitoring, measurement of MDA excretion in urine over 24 hours, occurred during week 2. Surface contamination of the workplace and equipment was monitored qualitatively by colorimetric wipe samples. Results and conclusions-Geometric means of daily exposure ranged from 81-1762 µg MDA for glove monitoring and from 84-1783 µg MDA for hand washes. No significant diVerences, except for one worker, were found between exposure of the hands in weeks 1 and 2. Significant diVerences between the mean daily exposure of the hands (for both weeks and sampling methods) were found for all workers. The results of the colorimetric wipe samples indicated a general contamination of the workplace and equipment. Excretion of MDA in 24 hour urine samples ranged from 8 to 249 µg MDA, whereas cumulative MDA excretion over a week ranged from 82 to 717 µg MDA. Cumulative hand wash and MDA excretion results over a week showed a high correlation (R 2 =0.94). The highest actual daily dermal exposure found seemed to be about 4 mg (hand wash worker A on day 4), about 25% of the external DOEL. Testing of compliance by means of a biological limit value (BLV) led to similar results for the same worker. It is concluded that both dermal exposure monitoring methods were applicable and showed a compatible performance in the present exposure scenario, where the exposure relevant to dermal absorption is considered mainly restricted to hands. The concept for a DOEL seemed to be relevant and applicable for compliance testing and health surveillance in the situation under investigation. (Occup Environ Med 1998;55:805-811)

Proposal for the assessment of quantitative dermal exposure limits in occupational environments: Part 1. Development of a concept to derive a quantitative dermal occupational exposure limit.

“…12 In this study a significant correlation was found between cumulative MDA excretion in urine and the results of the dermal exposure measurements (assessed by hand washing). Testing for compliance was performed both by comparison between the MDA excreted in the urine and a BLV, and by comparison between the estimated external dermal exposure (hand wash method) and the external DOEL as derived in this report.…”

“…Both comparisons were in close agreement, the exposure was estimated to be 20%-25% of the BLV and DOEL, respectively. 12 As stated before, one of the first steps now is to develop criteria to set a priority list of chemicals for which a DOEL is a useful and necessary tool in occupational health risk management. For this purpose the publications of ECETOC and US EPA and others may provide some basic elements, but these need further development and evaluation.…”

“…Furthermore, the DOEL seemed to be relevant and applicable for MDA in an actual occupational setting. 12 We recommend the testing of this approach for more substances in practice.…”

“…The third phase is presented in an accompanying paper. 12 The present reports are considered to serve as a starting point for the development of DOELs, and are not meant to be the final guidance for the derivation for a DOEL.…”

A Method for Assessing Occupational Dermal Exposure to Permanent Hair Dyes

“…The techniques for assessing dermal exposure can be divided into three categories (Brouwer et al, 1998;Cherrie et al, 2000) as follows.…”