1,2-Dichloroethane; TSCA Review

1."Whether and how exposure controls and personal protective equipment (PPE) are used during the manufacture, processing, and use of 1,2-dichloroethane for each of the COUs. Although EPA has test order data, additional information on when and where exposure controls and PPE are used would be informative" (EPA 2025a). AIHA encourages EPA to better understand the context in which the material/chemical is used to better control exposures. Industrial hygienists are often controlling exposures to several chemicals at the same time. Thus, evaluations of single chemical exposures is not preferrable when evaluating chemical exposures and evaluating risk. Risk management should be performance based and multifaceted. Overly prescriptive measures can lead to unintended adverse consequences to worker health resulting from heat stress, loss of dexterity, tripping, or ergonomic issues. 2."Information to help clarify the approach EPA used to analyze OSHA CEHD, specifically the step of removing data in which all measurements taken at the site were recorded as ''0'' or below the limit of detection and there was no evidence such as a bulk sample that shows the presence of the chemical at the site as EPA assumed that the chemical of interest may not have been at the site at the time of sampling" (EPA 2025a) Industrial hygienists interpret censored data following AIHA's "A Strategy for Assessing and Managing Occupational Exposures: 4th Edition" (Hewett, 2015). AIHA offers free training on Bayesian statistical tools for making accurate exposure judgments based on limited and/or censored data. Removing censored data can lead to biased judgments and decisions about exposure conditions in the workplace. 3.EPA solicits comment on "Information on OESs for which EPA has slight confidence on exposures to workers and ONUs (Repackaging, Industrial and commercial aerosol products, and Waste handling, treatment, and disposal landfills, including on the degree to which 1,2- dichloroethane is used in Industrial and commercial aerosol products" (EPA 2025a) In most high-end scenarios and some central tendency scenarios, EPA has estimated lower exposures for ONUs than for "average workers." Workers engaged in maintenance, repair and/or cleaning of machines and/or containers with the substance being evaluated are likely to have higher peak or even average exposures than production workers who work directly with the substance under evaluation. Therefore, ONU exposures need to be analyzed separately from production workers and workers exposed incidentally. 4."Information (e.g., SDS documents) to inform the level of 1,2-dichloroethane in adhesives. The concentration evaluated for the dermal exposure for the Industrial application of adhesives and sealants OES is 91.8 percent based on an SDS for an adhesive containing 1,2-dichloroethane" (EPA 2025) AIHA would encourage EPA to better characterize those exposure determinants that dictate which dermal exposure estimation approach is preferred for a given chemical and its conditions of use. The DRAFT Risk Evaluation for 1,2-Dichloroethane EPA noted "Dermal exposure data were not reasonably available for the conditions of use in the assessment. Because 1,2-dichloroethane is a volatile liquid that readily evaporates from the skin, EPA estimated dermal exposures using the Dermal Exposure to Volatile Liquids Model. This model determines an APDR [acute potential dermal dose rate] based on an assumed amount of liquid on skin during one contact event per day and the theoretical steady-state fractional absorption for 1,2-dichloroethane." (EPA 2025b: p. 29). In prior risk evaluations, a fractional absorption approach was used by EPA for estimation of dermal exposure. Frasch et al. (2014) identified limitations that should be considered when applying a fractional absorption approach (effects of loading or evaporation, duration of experimentation to derive percent absorbed, and latent absorption). Lynch et al. (2023)…