Target level occupational exposure limit

Various standards and guidelines have been developed for sulfur mustard. These values are applieable to occupational exposures, emergeney planning and response efforts, and remediation efforts. Airborne exposure limits (AELs) and health-based environmental sereening levels (HBESLs) for sulfur mustard have been developed by the US Army (USACHPPM, 1999, 2000). Most health-based criteria for sulfur mustard vapor exposure are based upon protection of the eyes and respiratory traet whieh are the most sensitive targets. 

Fortunately the Health and Safety Executive (HSE) publishes each year a booklet called EH40, which lists the chemicals and dusts that are subject to control. The HSE defines two levels of control the maximum exposure limit (MEL), which must never be exceeded and the occupational exposure standard (OES) which is a realistic target for the workplace. 

One theory of the mechanism of acute selenium toxicity concerns inactivation of the sulfhydryl enzymes necessary for the oxidative reactions in cellular respiration (Lombeck et al. 1987 Mack 1990 Shamberger 1981). Acute toxic effects, such as pulmonary edema, can result in respiratory failure and death. The lung, however, does not appear to be a target organ at levels of exposure less than the occupational permissible exposure limits (PELs) or threshold limit values (TLV). 

Many common VOCs have well-documented health effects at elevated levels. In most indoor environments however, the exposure is described as low since concentrations are negligible in comparison to occupational limit values. Sensory responses to VOCs also include odor response, nasal irritation (pungency) and eye irritation ( Devos et al., 1990 and Cometto-Mu iz and Cain, 1990). The maximum concentrations determined in Singapore buildings were compared with some of the common health and comfort guidelines. The values are presented in Table 10.5. It is observed that the maximum concentrations for the majority of the target compounds are within recommended guidelines. Levels are very low as compared to threshold limit values related to health and irritation. 

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