On March 25, 2024,  the US Environmental Protection Agency (EPA) issued a fourth test order under the Toxic Substances Control Act (TSCA) to require testing for per- and polyfluoroalkyl substances (PFAS) as part of the National PFAS Testing Strategy. This is the latest step taken under EPA’s PFAS Strategic Roadmap. 

Test Order for NMeFOSE 

Under the terms of this action, Wacker Chemical Corporation and 3M Company are required to test 2-(N-Methylperfluoro-1-octanesulfonamido) ethanol (NMeFOSE) for physical and chemical properties, as well as potential inhalation health effects after. NMeFOSE is found in various products such as clothing, carpet treatments, furniture coatings, biosolids, and air. It can also be found in outdoor environmental media, indoor dust, and indoor air. 

After carefully reviewing available hazard and exposure data, EPA has determined that there may be an excessive risk of harm to human health or the environment from NMeFOSE. Cancer and damage to the immune and neurological systems are possible side effects of exposure to the chemical. The test order will assist EPA better understand the potential risks and exposures related to NMeFOS.                                                                                                                    
EPA encourages the companies to conduct the test together to avoid unnecessary duplication of tests. Companies covered by the test order have two options: either carry out the tests as specified in the order or provide any known information that meets the order's criteria. EPA will also consider potential combinations of tests to reduce the time, animals, and costs required.

                                                                                                             
The order goes into effect on March 25, 2024, and EPA must receive the results of all first-tier tests within one year to determine what additional tests are required. 

National PFAS Testing Strategy 

EPA is ordering tests for PFAS in categories where toxicity data are lacking to understand their potential effects on human health and the environment. The strategy aims to increase consideration of exposures and stakeholder input in determining which specific PFAS should be tested and improve their classification and universe. 

Section 4 Test Orders  

The TSCA Section 4 Order development process is complex and resource-intensive, involving a range of specialists to establish testing requirements, methodology, and financial impact estimates. EPA often covers multiple companies and their points of contact and resolves claims of confidential business information to increase transparency. This process involves identifying companies and their points of contact to ensure that EPA can effectively link the company to the chemical substance. 

The U.S. Agency for Toxic Substances and Disease Registry (ATSDR) has established minimum risk levels (MRLs) for 1,1,1-trichloroethane. Although the use of these substances has decreased significantly in recent years, there is still some potential for human exposure. According to the ATSDR toxicological profile released on March 29, some production of 1,1,1-trichloroethane persists.

U.S. facilities have reported quantities of this substance to databases of the Environmental Protection Agency (EPA) such as the Toxics Release Inventory and Chemical Data Reporting. These facilities primarily handle or dispose of hazardous waste, including substantial amounts of 1,1,1-trichloroethane.

Introduction:

1,1,1-trichloroethane, a synthetic compound, does not occur naturally but is released into the environment as a result of human activities. Heating it or using it in welding can produce the toxic gas phosgene. It's commonly found in soil and water, especially at hazardous waste sites, with its vapor form being prevalent due to its high volatility. Historically, it has been widely used in both industrial and domestic settings as a solvent for dissolving substances such as glues and paints, as well as for degreasing manufactured parts and in various household products such as spot cleaners, glues, and aerosol sprays.

History:

After January 1, 2002, the U.S. Environmental Protection Agency (EPA) banned domestic use of 1,1,1-trichloroethane due to its impact on the ozone layer. Limited production for essential uses continued until 2005, with export production permitted until 2012. The phase-out of U.S. production was mandated by Section 604 of the Clean Air Act and the Montreal Protocol. Although not completely halted, production of 1,1,1-trichloroethane was scheduled to cease by 2012 under the Montreal Protocol agreements, contributing to a decline in ambient levels despite ongoing production.

Side Effects of Exposure:

Health effects observed in controlled human exposure studies include impaired cognitive skills, manual dexterity, balance and coordination. Animals show signs of central nervous system depression, such as impaired performance, ataxia, and unconsciousness, similar to humans. Neurochemical, behavioral, and physiological changes have also been observed. Case reports suggest that high concentrations of 1,1,1-trichloroethane may cause hepatic effects in humans, including changes in liver enzymes and progressive liver disease. Consistent findings in animal studies indicate hepatic effects after inhalation exposure, including increased liver weight, fatty changes, and hepatocyte swelling.

ATSDR Established Minimal Risk Levels (MRLs) for 1,1,1-Trichloroethane:

The purpose of MRLs is to serve as screening thresholds used by ATSDR health assessors and other responders. Their aim is to identify contaminants and potential health effects that may be of concern at hazardous waste sites.