10.07.2021 Unpacking the TSCA Polymer Exemption
Manufacturers of chemical substances in the United States are well aware of the regulatory burdens placed on their industry by the Toxic Substances Control Act (TSCA). TSCA requirements can be cumbersome and difficult to understand. Fortunately, TSCA contains several exemptions offering relief for companies in certain circumstances.
One TSCA exemption applies to companies manufacturing polymers, if the manufacturer can meet conditions making the polymer unlikely to present an unreasonable risk to human health or the environment. The polymer exemption removes the regulatory burden of TSCA premanufacture notification (PMN) requirements from manufacturers of substances that are relatively stable and inert.
To qualify for the polymer exemption, a company must ensure the polymer it intends to manufacture meets three general criteria: (1) the substance must meet the regulatory definition of a “polymer;” (2) the substance must meet certain molecular weight or composition requirements; and (3) no regulatory exclusions from the exemption may apply.
Definition of A Polymer
The seemingly obvious initial criterion for the TSCA polymer exemption is that the substance must in fact be a “polymer,” as the term is defined by regulation. TSCA defines a polymer to be a chemical substance in which greater than 50% of the molecules are composed of at least 3 monomer units plus at least one other monomer unit or other reactant; and less than 50% of the molecular weight of the substance may be comprised of molecules of any one molecular weight.
Molecular Weight and Composition Criteria
Assuming the chemical substance is in fact a “polymer,” the polymer must also meet molecular weight requirements or be a polyester to be eligible for exemption. If the average molecular weight of the polymer is between 1,000 and 10,000 daltons, the oligomer content of the polymer must be less than 10% by weight below 500 daltons and less than 25% by weight below 1,000 daltons. If the average molecular weight is greater than 10,000 daltons, the oligomer content must be less than 2% below 500 daltons and less than 5% below 1,000 daltons. The polymer may also qualify if it contains at least two carboxylic acid ester linkages, at least one of which links internal monomer units together, making the polymer a “polyester.”
To be exempt, an otherwise eligible polymer may not possess any of four exclusionary conditions in the regulation. First, the polymer may not be cationic or reasonably anticipated to become a cationic polymer in a natural aquatic environment (e.g., rivers, lakes) unless:
- the polymer is a solid material not soluble or dispersible in water and will be used only in solid phase (e.g., polymers for use as ion exchange beads), or
- the combined (total) functional group equivalent weight of cationic groups in the polymer is equal to or greater than 5,000.
Second, the polymer must be made up of at least two of the atomic elements of carbon, hydrogen, nitrogen, oxygen, silicon, and sulfur. The polymer may not be exempt if it includes (as an integral part of composition, not including impurities) elements outside of the those allowed by regulation. Third, polymers manufactured or imported from monomers and reactants not on the TSCA Chemical Substance Inventory may not be exempt.
Finally, if it is reasonably anticipated the polymer will undergo substantial degradation, decomposition, or depolymerization, the polymer is excluded from exemption. Under normal use, if the polymer is expected to break down into simpler, small weight substances as the result of oxidation, hydrolysis, heat, sunlight, attack by solvents, or microbial action, the polymer may not be exempt. However, this exclusion does not apply to normal landfill degradation over a long period of time, but rather significant degradation in, for instance, a waste treatment system. Minor byproduct degradative reactions do not exclude the polymer from exemption.
Reporting and Recordkeeping
Importantly, the TSCA polymer exemption is self-executing, meaning no application to or approval from EPA is required. However, companies manufacturing exempt polymers are subject to certain reporting and recordkeeping requirements. The manufacturer must carefully document exemption evaluation and create a Certification Statement, including the following statements:
- The substance is manufactured or imported for a commercial purpose other than for research and development.
- All information in the certification is truthful.
- The new chemical substance meets the definition of a polymer, is not specifically excluded from the exemption, and meets the conditions of the exemption in federal regulations.
The manufacturer must maintain evidence of the exemption (calculations, exclusion evaluations, etc.), the Certification Statement, the date of commencement of manufacture, and documentation of 3 years production volumes onsite for at least 5 years from the date manufacture commences. This information must be made available to EPA upon request but is not required to be submitted on any established basis.
Finally, the manufacturer must submit an “Exemption Report” to EPA by January 31 of the year following initial manufacture, in which the company simply provides a name, address, and phone number of a technical contact, and the number of exempt polymers manufactured in the preceding year.
While the TSCA polymer exemption requirements may seem complex, the alternative of undergoing EPA’s PMN process is far more onerous, costly, and uncertain. Companies intending to manufacture polymers for distribution in commerce should seriously consider evaluating them for potential TSCA exemption.