- Exposure to CCP or its components may rarely cause allergic contact dermatitis.
- This conclusion is based on published case reports of allergic contact sensitization and results reported in several industry-sponsored RIPT studies. Cases of allergic contact dermatitis were reported only in RIPT studies from the 1970s that were submitted to the 1987 NIOSH docket; no cases were reported in the studies submitted to the 1997 docket. This fact may indicate that the CCP component responsible for the allergic contact dermatitis observed in the early studies was removed from the more recent formulations of CCP.
- Systemic reactions have occurred in a few persons exposed to CCP.
- This conclusion is based on the finding that three such cases have been reported in the peer-reviewed medical literature. No cases have been reported in the last 7 years, and thus there is no evidence that current exposures to CCP present a risk for this health outcome.
- Data are insufficient to evaluate claims of other adverse health effects (such as neurologic effects and reports of multiple chemical sensitivity [MCS]) that have been suggested in some of the clinical reports submitted to the NIOSH docket.
In conclusion, although the weight of the evidence indicates that exposure to CCP in the past has resulted in adverse health effects, it is uncertain whether current formulations of CCP represent a significant risk to exposed workers. Only a few cases of systemic reactions and allergic contact dermatitis have been reported in the United States or in Europe, which suggests that the risk of these serious outcomes is extremely low given the large number of people who have been exposed to CCP over a period of many years. Recently conducted experimental studies in humans (RIPT studies) suggest that the potential for skin irritation from exposure to current formulations of CCP is nonexistent, or at most slight. However, it is unclear how well these experimental studies simulate the exposures and potential responses of CCP users—particularly heavy users. Data from industry reporting systems suggest no widespread problem and in fact indicate a decrease in health-related complaints in recent years despite an increase in CCP production. However, these passive reporting systems are unlikely to capture all or even most cases of CCP-related health effects, and changes in publicity about CCP may have caused fluctuations in the reporting of cases. Since the 1980s, no epidemiologic studies have been conducted to determine irritative symptoms among U.S. workers exposed to CCP [Mendell et al. 1991]. A positive epidemiologic study was conducted in Finland in 1991 [Jaakkola and Jaakkola 1999]. However, the relevance of these findings for U.S. workers may be limited because of differences between the CCP products used in Europe and the United States. Thus information is lacking about the prevalence of irritation of the eyes, skin, and upper respiratory tract among workers currently handling CCP in the United States.
Recommendations
NIOSH recognizes that it may occasionally be necessary to limit CCP exposure in certain workers through administrative controls (such as job rotation). But in most cases, implementing normal precautions and recommendations for maintaining acceptable indoor air quality should be adequate to reduce or eliminate symptoms. Good industrial hygiene and work practices are likely to prevent symptoms from potent irritants (such as formaldehyde) that