Occupational exposure limits for reproductive toxicants - A comparative analysis.

We investigated the level of protection of reproductive and developmental toxicity offered through occupational exposure limits (OELs) and Derived No-Effect Levels for workers' inhalation exposure (wDNELs). We compared coverage of substances that have a harmonised classification as reproductive toxicant 1 A or 1B (Repr.1 A/B), numerical values and scientific basis of 12 lists of OELs and wDNELs from REACH Registrants' and the Committee for Risk Assessment. Across the 14 sources of OELs and wDNELs, 53 % of the Repr1A/B-substances had at least one exposure limit (counting groups of metals as one entry). Registrants' wDNELs covered the largest share, 40 %. The numerical values could be highly variable for the same substance across the lists. How often reproductive toxicity is identified as the critical effect varies between the examined lists, both due to different assessments of the same substance and different substance coverage. Reviewing the margin of safety to reproductive toxicity cited in the documents, we found that 15 % of safety margins were lower to reproductive toxicity than the critical effect. To conclude, neither the REACH nor work environment legislation supply wDNELs or OELs for a substantial share of known reproductive toxicants. EU OELs cover among the fewest substances in the range, and in many cases national OELs or wDNELs are set at more conservative levels.

Toxicity assessment and health hazard classification of stainless steels.

Stainless steels are widely used iron-based alloys that contain chromium and, typically, other alloying elements. The chromium(III)-rich surface oxide of stainless steels efficiently limits the release (bioaccessibility) of their metal constituents in most physiological environments, influencing the toxicity of the alloy. Of the constituents and impurities of stainless steels, nickel and cobalt are of particular interest, primarily due to skin sensitization and repeated-dose inhalation toxicity of nickel, and (inhalation) carcinogenicity of cobalt. A review of the available toxicological data on stainless steels, and the toxicological, mechanistic, and bioaccessibility data on their constituent metals supports the low toxicity and non-carcinogenicity of stainless steels. The comparative metal release, rather than the bulk composition of stainless steels, needs to be considered when assessing their health hazard classification according to the UN Globally Harmonized System, and the corresponding EU CLP regulation. As an illustrative example, a 28-day inhalation toxicity study on stainless steel powder showed no signs of lung toxicity at exposure levels at which significant toxicity would have been expected on the basis of its bulk nickel content. This finding is associated with the low bioaccessibility of nickel from the alloy in the lungs.

Diesel Engine Exhaust: Basis for Occupational Exposure Limit Value.

Diesel engines are widely used in transport and power supply, making occupational exposure to diesel exhaust common. Both human and animal studies associate exposure to diesel exhaust with inflammatory lung effects, cardiovascular effects, and an increased risk of lung cancer. The International Agency for Research on Cancer has evaluated diesel exhaust as carcinogenic to humans. Yet national or regional limit values for controlling occupational exposure to diesel exhaust are rare. In recent decades, stricter emission regulations have led to diesel technologies evolving significantly, resulting in changes in exhaust emissions and composition. These changes are also expected to influence the health effects of diesel exhaust. This review provides an overview of the current knowledge on the health effects of diesel exhaust and the influence of new diesel technologies on the health risk. It discusses the relevant exposure indicators and perspectives for setting occupational exposure limit values for diesel exhaust, and outlines directions for future research. The review is based on a collaborative evaluation report by the Nordic Expert Group for Criteria Documentation of Health Risks from Chemicals and the Dutch Expert Committee on Occupational Safety.

Consolidating exposure scenario information for mixtures--experiences and challenges.

INTRODUCTION: The requirements of the European Union Regulation on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), including the preparation of exposure scenarios for the communication of safe use, are focused on single substances. Since the chemical products used at workplaces are typically mixtures, it is important to ensure that accurate information is available regarding their safe use. The focus of the present study was on the methods for consolidating (combining) the information presented in the exposure scenarios of the individual components of a mixture. METHODS: We tested the applicability and comparability of three methods for consolidating the exposure scenario information on six real products, focusing on occupational exposure. Two of the reviewed methods were based on the identification of the critical components that determine the health effects and risk management of the product, and one was based on the selection of the most stringent risk management measures presented in the exposure scenarios of the components. RESULTS: The differences in the critical components recognised by the two critical component-based methods revealed limitations in both of the methods. The quality and comprehensiveness of the consolidated scenarios produced by the two methods were generally of the same level, depended directly on the content of the exposure scenarios of the critical components. Choosing the most stringent risk management measures improved the comprehensiveness of the scenarios. All of the examined methods run the risk of communicating over-precautionary measures if the concentration of the components determining the level of protection is not taken into consideration. CONCLUSIONS: Of the three methods considered, we recommend the selection of the most stringent operational conditions and risk management measures as a conservative default approach for consolidating exposure scenario information. If a critical component-based approach is used, checking the adequacy of the consolidated scenario for the other components of the mixture is recommended. With all of the methods, further modification of the consolidated scenario may be necessary to achieve the intended level of protection.

Methodology for national risk analysis and prioritization of toxic industrial chemicals.

The identification of chemicals that pose the greatest threat to human health from incidental releases is a cornerstone in public health preparedness for chemical threats. The present study developed and applied a methodology for the risk analysis and prioritization of industrial chemicals to identify the most significant chemicals that pose a threat to public health in Finland. The prioritization criteria included acute and chronic health hazards, physicochemical and environmental hazards, national production and use quantities, the physicochemical properties of the substances, and the history of substance-related incidents. The presented methodology enabled a systematic review and prioritization of industrial chemicals for the purpose of national public health preparedness for chemical incidents.