Washed Cotton in The 1978 OSHA Cotton Dust Standard

Current Intelligence Bulletin 56

"Those whose commitment is to the public's health must simultaneously follow promising lines of inquiry while taking maximum advantage of what is presently known to control or eliminate occupational disease" [Wegman et al. 1983].

Introduction

In 1971, the Occupational Safety and Health Administration (OSHA) adopted a 1-mg/m³ (total dust) permissible exposure limit (PEL) for cotton dust. Subsequent OSHA rulemaking led to the eventual promulgation of a comprehensive Federal occupational health standard for cotton dust in 1978 [43 Fed. Reg. 27351 (1978)]. In the 1978 standard, OSHA established different 8-hr time-weighted average (TWA) PELs for gravimetrically measured airborne cotton dust for different work areas of textile mills. In the absence of any known "safe level of exposure" [41 Fed. Reg. 56498-56527 (1976)], the lowest PEL—200 µg/m3 (0.2 mg/m³) of airborne dust as measured by the vertical elutriator cotton dust sampler—was considered the lowest feasible level that could be achieved in many operations [NIOSH 1974].

As with all comprehensive standards promulgated by OSHA, the 1978 standard included provisions for medical monitoring of workers and administrative controls as adjuncts to dust control for prevention of occupational respiratory disease from cotton dust exposure. In fact, by the early 1980's, these approaches together appear to have accounted for a substantial reduction in the prevalence of byssinosis in many U.S. cotton textile mills [Merchant 1983]. However, a NIOSH-sponsored committee remained concerned that "even at very low concentrations of cotton dust, a considerable proportion of cotton textile workers may be at risk of developing byssinosis" [ASPH 1986]. (This concern reflected an earlier NIOSH conclusion that "even at levels of 0.1 or 0.2 mg/cu m there has been a definite incidence of byssinosis" [NIOSH 1974]. The concern was recently supported by evidence suggesting that dust-related accelerated decline in cotton textile workers' lung function occurs even at the 200-µg/m³ PEL among those who smoke [Glindmeyer et al. 1991].)

The continuing (albeit much lower) risk of byssinosis, the costs of further controlling dust, and the realized and potential future costs of compensating affected workers represented ample reasons to pursue alternative preventive strategies, including substitution of cotton treated to reduce toxicity for untreated cotton in textile mills [Millar 1988].