Polymer Exemptions

The advantageous regulatory position, which, due to the polymer exemption , simplifies the protocols for the introduction of new products to the market... 

The use of the additive molar Cpx function is restricted to polymers exempt from halogen. Halogen atoms are in-built soot formers (and consequently in-built flame retardants in the presence of oxygen) engaged in secondary reactions, thus influencing the char formation markedly. 

Substances not on the Inventory or are not otherwise excluded or exempt are considered new and are subject to a premanufacture notice (PMN). Examples of exclusions would include mixtures, substances subject to another statute, impurities, by-products and nonisolated intermediates. Additional exemptions also include test marketing products, low volume products, polymer exemptions, LoREX (low release and exposure exemption), and R D substances. By statute, chemical manufacturers must notify the Agency at least 90 days before manufacturing a chemical substance that is not listed on the TSCA Chemical Substance Inventory. However, TSCA does not empower the US EPA to require routine testing of new chemicals to permit a valid evaluation of the potential risks. This has been a limitation in the overall effectiveness of the PMN process. Erequently, very little data accompanies the PMN (50% of submissions present no safety data and 90% have only an LD50 and an Ames test) however, the EPA must decide within 90 days if the submitted chemical will pose a health or environmental hazard. 

The two-percent rule has been used since the development of the TSCA Inventory in the determination as to which reactants must be included in naming the polymer for TSCA purposes. The two-percent rule means that monomers and reactants of a polymer that are used or incorporated at no more than 2 wt%, may be, but need not be, included in the considerations leading to the formal chemical description of a polymer manufactured from those precursors [3]. It is the submitter s choice as to whether he/she wishes to have these reactants considered or not considered in describing a polymer. There is no choice for precursors used or incorporated (whichever is less) at more than two weight percent. These precursors must be included in the information reported, and, ordinarily, they will be reflected in the name of the polymer. The two-percent rule has not meant that a precursor reflected in the description of a polymer must be used [4] or incorporated [5] at more than two weight percent. Therefore, any precursor reflected in description of a polymer can be used at any concentration greater than zero, but a precursor must not be completely omitted. These applications and interpretations of the two-percent rule also applied under the initial polymer exemption of 1983. 

Historically, only the used calculation for the concentration of a precursor was available but, in 1995, the incorporated calculation was added. Where the percent incorporated can be determined and supported by analytical results, this method of calculation can lead to a lower percentage of certain reactants for decision-making instead of using the calculation for the percent used. A new polymer may also be chemically identical to an existing polymer based on the degree of the precursor s incorporation. One may suppose that under the polymer exemption promulgated in 1995, the two-percent... 

One situation that may not be entirely clear is whether a polymer that was initially manufactured under the polymer exemption with a given monomer or reactant used or incorporated at greater than 2 wt% is the same polymer under the exemption if the same monomer or reactant is subsequently used or incorporated at a concentration that is equal to or less than 2 wt%, but greater than 0 wt%. Based on EPA guidance, it would appear that the subsequent version of the polymer as just described would be the same polymer under the exemption as the initial polymer. In the Guidance Document, the EPA states that ... 

The definition of polymer under the TSCA polymer exemption is the same as that used in the EU, but there are two other criteria required to qualify under the PMN exemption. These are that the polymer meets one of three exemption criteria, and that it not be rendered ineligible due to one of five exclusions. 

The regulatory benefit of meeting the polymer exemption requirements is that a PMN under TSCA Section 5 need not be submitted to the EPA before starting commercial manufacture or importation of a polymer that is not on the TSCA Inventory. Only a one-time notice must be sent to the EPA indicating that the company has used the polymer exemption, and this brief notice need not include the chemical identity of the polymer. 

The basic definition of polymer used in many countries, including the US under the TSCA polymer exemption and Canada under CEPA, is the one first developed in Europe under the Sixth Amendment to Directive 67/548/EEC and retained in REACH. This definition provides as follows ... 

In Canada, polymers are defined under the CEPA in the same manner as they are in the EU and under the polymer exemption in the US, but the regulatory implications are different. In Canada, all types of new polymers (those not present on the DSL) must be notified (unless manufactured or imported in certain small quantities), unlike the general exemption in the EU or the specific polymer exemption in the US. As mentioned previously, meeting the polymer definition in Canada allows the substance to be notified as a polymer and not a chemical, which reduces the amount of test data and other information that must be submitted. Therefore, it is critical that a substance be carefully analysed, particularly for molecular weight distribution, so that its notification in Canada as a polymer is validated. 

Other factors used to determine if a polymer meets the RRR criteria are similar to those used in the determination as to whether a substance qualifies for the polymer exemption in the US, but subtle differences exist. Eor example, in the US, if one of the reactants used at greater than two weight percent to manufacture a polymer is not on the TSCA Inventory or covered by an applicable Section 5 exemption, this fact alone will disqualify the polymer from meeting the polymer exemption criteria. In Canada, such a situation would not disqualify a polymer from being considered to be RRR, although the reactant s presence on the DSL does affect which Schedule of data must be submitted. 

Perhaps the polymer exemption approach in the US under the TSCA comes closest to striking a balance between the overly lenient approach in the EU and the overly conservative approach in Canada. The molecular weight requirements and restrictions on reactive functionalities and certain physical attributes defined under the exemption go a long way toward defining a better way of regulating polymers. This approach could resolve the legal issue under REACH involving the requirement that monomers in reacted form in polymers... 

Since 1979, EPA s New Chemicals Program has reviewed almost 30,000 new chemicals, including 22,000 PMNs, which were fully reviewed and 5500 low-volume, test market, and polymer exemptions. During this period, the Agency claims that the TSCA has prevented potential risks to people and the environment from nearly 2700 new substances. 

Polymer Exemption Guidance Manual, EPA 744-B-97-001, 36, question 1 (June 1997), available at http //www.epa.gov/oppt/newchems/pubs/polyguid.pdf [hereinafter Polymer Exemption Guidance Manual]. 

The two percent rule also defines how broadly Inventory listings of polymers may be interpreted. The second place it makes its appearance is in the polymer exemption rule where it is used as part of the definition of polymers exempt from the PMN requirements of TSCA 5. °... 

Is the substance exempt from coverage under the PMN program because of a self-executing exemption such as the R D exemption or the polymer exemption If it is exempt pursuant to a self-executing exemption, no PMN is necessary. 

These polymers are eligible for the polymer exemption, but companies have the option of filing PMNs for them. http //www.epa.gov/oppt/newchems/pubs/hmwtpoly.htm... 

The United States Environmental Protection Agency (EPA) has authority under the statute to grant additional exemptions under TSCA 5(h)(4) if the manufacture, processing, distribution in commerce, use or disposal of a substance will not present an unreasonable risk of injury to health or the environment. Several exemptions have been promulgated under this authority, including the polymer exemption, the LVE and LoREX exemptions, and the Polaroid exemption. 

The EPA s polymer exemption was first instituted in 1984 and was later broadened in 1995. The 1985 exemption has some legacy appHcation, but the 1995 polymer exemption is currently in effect for all polymers made or imported since May 30,1995. 

There is a pending rulemaking to require certain classes of polymers with perfluorinated units—polymers in which fluorine atoms are substituted for the hydrogen atoms that are present in many polymers—to go through the PMN process. The proposed rule would make the polymer exemption unavailable for these polymers because, as the EPA explained in its proposed rule, the EPA could not assume that all such polymers are risk-free. The EPA cited liver, developmental, and reproductive toxicity at very low exposure levels as well as data that indicates that some perfluorinated polymers maybe carcinogens. These generalizations have been criticized by the chemical industry. ... 

The polymer exemption is an exemption from the premanufacture notice requirements and not an exemption from all of the many programs under the Toxic Substances Control Act. An exempt polymer is subject to all of the other TSCA programs, including (but not limited to) the substantial risk reporting in 8(e) of the statute, Significant New Use Rules, import certifications, and export notifications. 

The first condition for the polymer exemption is that the substance must meet the definition of a polymer stated in the exemption, which is not the same as a chemist s definition of a polymer. This regulatory definition is also not the same as the definition the EPA uses for Inventory purposes, andis just a small subset of that much broader definition. To keep all of the different... 

The second condition for the polymer exemption is that the substance cannot be specifically excluded. In practical terms, this means that once a person determines that the substance meets the definition of polymer, he or she must also check the list of exclusions to be certain that the substance is not excluded from the polymer exemption. If the substance is excluded, then no one can manufacture or import it without going through the PMN process. 

Cationic polymers must go through the PMN process, with two exceptions. The first exception is for solid polymers that are not dissolved or dispersed in water, and are only used in the solid phase. Ion exchange materials are examples of these cationic solid polymers that do qualify for the polymer exemption. The second exception is for polymers that are large compared to the number of cationic groups. If the combined functional group weight of... 

Polymers that have elements outside of ranges in 40 C.F.R. 723.250(d)(2) are excluded from the polymer exemption, and anyone who is going to manufacture them or import them must file a PMN if they are not already on the Inventory. This exclusion requires that a polymer that qualifies for the polymer exemption must ... 

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