Draft Revisions to Risk Determinations Released for 4 Chemical Substances
Draft revisions to the risk determinations for four chemical substances were recently issued by the U.S. Environmental Protection Agency (EPA). Here we take a brief look at these chemicals (methylene chloride, N-methylpyrrolidone, perchloroethylene, and trichloroethylene) and the associated revisions.
Revisions to Risk Determinations
The chemical substances for which draft revisions were recently issued are shown in the table below. These substances are among the first ten chemicals undergoing risk evaluation under the Toxic Substances Control Act (TSCA).
| Chemical Name | CAS Registry Number | Chemical Formula |
|---|---|---|
| methylene chloride | 75-09-2 | CH2Cl2 |
| N-methylpyrrolidone | 872-50-4 | C5H9NO |
| perchloroethylene | 127-18-4 | C2Cl4 |
| trichloroethylene | 79-01-6 | C2HCl3 |
Source: U.S. Environmental Protection Agency
For the revised risk determinations, the EPA is utilizing a “whole chemical approach”. With this, the Agency determined that each chemical (considered as a whole chemical substance) presents unreasonable health risks under its conditions of use.
Methylene Chloride
- For methylene chloride, it was established that the whole chemical determination of unreasonable risk was driven by 52 of the 53 use conditions evaluated by the EPA. In methylene chloride’s revised risk determination, there is not an assumption that PPE is appropriately worn at all times by workers. Without this assumption, five additional use conditions plus the initial 47 conditions support the determination of unreasonable risk.
N-methylpyrrolidone (NMP)
- For NMP, it was determined that the whole chemical determination of unreasonable risk was driven by 29 of the 37 conditions of use that the Agency evaluated. In the revised risk determination for NMP, there is not an assumption that PPE is appropriately worn at all times by workers. Without this assumption, three additional use conditions plus the initial 26 conditions drive the unreasonable risk determination.
Perchloroethylene (PCE)
- For PCE, it was established that the whole chemical determination of unreasonable risk was driven by 60 of the 61 use conditions evaluated by the EPA. In PCE’s revised risk determination, there is not an assumption that PPE is appropriately worn at all times by workers. Without this assumption, one use condition plus the initial 59 conditions support the determination of unreasonable risk.
Trichloroethylene (TCE)
- For TCE, it was determined that the whole chemical determination of unreasonable risk was driven by 52 of the 54 conditions of use that the Agency evaluated. In the revised risk determination for TCE, there is not an assumption that PPE is appropriately worn at all times by workers. Without this assumption, however, no use conditions in addition to the initial 52 conditions drive the unreasonable risk determination.
Additional Information
More information regarding the aforementioned risk determination revisions may be found on the EPA’s website as it becomes available. Additionally, you can visit the ToxPlanet website and blog regularly for information on new developments.
Designed to help manage the impact of chemicals in the workplace and on the environment, ToxPlanet is used extensively by a broad spectrum of individuals, including toxicologists, pharmacologists, industrial hygienists, occupational physicians, product stewards, risk assessment professionals, hazardous materials/emergency management personnel, first responders, environmental managers, and a host of other chemical safety professionals.
Contact us to learn more about all of the valuable data that our solutions can provide, and to register for a Free Trial.
