Thought Leadership: The Toxic Substances Control Act and the Bioeconomy: Part 1, The Impact of Nomenclature on the Commercialization of Biobased Chemicals

By Richard E. Engler, Ph.D., special to The Digest

When I meet people from bioeconomy companies, I ask them about their products’ status under the Toxic Substances Control Act (TSCA). The most common answers I receive are: “TSCA doesn’t apply because our product is not toxic,” “TSCA doesn’t apply because our product is naturally occurring,” and “We are compliant with TSCA because we’re making something that’s already in commerce.” This usually leads to a more in-depth discussion of how TSCA works and its idiosyncrasies with respect to biobased products. I do not ask this to be accusatory, rather I want to be sure that companies understand their obligations so that they do not run afoul of the law. TSCA penalties can add up quickly (maximum $37,500 per violation per day) and can threaten nascent companies if they are not diligent.

Bioeconomy companies recognize that their products are subject to a variety of federal chemical regulations, especially if they sell food, food additives, cosmetics, or other products regulated by the U.S. Food and Drug Administration (FDA). Unfortunately, companies may not recognize all the ways that the U.S. Environmental Protection Agency (EPA) regulates bioproducts, perhaps because of the understandable focus on the Clean Air Act (CAA) and the various programs under that authority: Renewable Fuel Standard, fuel additive registration, or other CAA submissions.

TSCA also applies to bioproducts used in industrial, commercial, and most consumer products, including fuels. TSCA reporting requirements are in addition to, and separate from, CAA reporting.
TSCA requires that a company must ensure that any chemical substance it intends to manufacture (or import) is listed on the TSCA Chemical Substance Inventory (the Inventory) or be subject to an exemption before commercial production occurs. If a substance is not listed on the Inventory, the manufacturer must submit a premanufacture notice (PMN) to EPA 90 days prior to producing or importing that substance.

The Importance of Identity

The first step in determining Inventory status is determining the appropriate Chemical Abstracts Index name for the substance. It is important to note that the existence of a Chemical Abstracts Index name or Chemical Abstracts Service (CAS) Registry Number does not mean that a substance is listed on the Inventory. In fact, many CAS identities do not comport with the TSCA nomenclature rules.

For a single, defined substance, such as ethanol, the identity is straightforward and a search of the Inventory can easily reveal if a substance is listed and if there are any restrictions to its manufacture, processing, or use. On the other hand, many biobased substances, like the petroleum substances they replace, are not single, defined substances. They are “unknown or variable composition, complex reaction products, or biological materials” (UVCB). For UVCBs, it is not sufficient to search the Inventory to find an identity that is “close.” UVCBs are typically identified by source and/or process and may include a definition in addition to the substance name. Triglyceride oils provide an instructive example of how the source is included in the substance identity.
Corn oil is listed on the Inventory as:
Corn oil.

Definition: Extractives and their physically modified derivatives. It consists primarily of the glycerides of the fatty acids linoleic, oleic, palmitic and stearic. (Zea mays).

(CAS registry number 8001-30-7).

It is a distinct substance from other vegetable oils, such as:

Soybean oil.

Definition: Extractives and their physically modified derivatives. It consists primarily of the glycerides of the fatty acids linoleic, oleic, palmitic and stearic. (Soja hispida).

(CAS registry number is 8001-22-7).

The definitions of these two oils are the same, except for the source names — Zea mays and Soja hispida. Even though the two oils are often used interchangeably because they have very similar fatty acid profiles, the different sources mean that these are two different substances under TSCA. A manufacturer of one could not rely on the identity of the other for TSCA purposes. Furthermore, the source-based name may also extend into a downstream product. For example, a fatty acid methyl ester (FAME) biodiesel made by the transesterification of corn oil with methanol would be:

Fatty acids, corn-oil, Me esters

(CAS registry number 515152-40-6),

while the soy FAME would be:

Soybean oil, Me ester

(CAS registry number 67784-80-9).

These two identities are distinct and a biodiesel producer would have to be sure that the corresponding FAMEs were listed on the TSCA Inventory before making biodiesel from either corn or soybean oil. The same is true for novel sources of triglycerides, such as algae, genetically modified microorganisms, or other non-traditional oil sources, even if they are otherwise identical to existing triglycerides listed on the Inventory. The source is included in the name, so each distinct source leads to a distinct chemical identity for products.

This can lead to a headache for TSCA reporting for your customers. Without a source-agnostic nomenclature system, manufacturers of biobased chemicals and any of their customers who transform those chemicals may be required to submit PMNs for each substance in the supply chain before manufacturing occurs. Both EPA and industry recognized that there is benefit to both if a system could be developed to draw equivalence without compromising human health and the environment; that recognition lead to the Soap and Detergent Association (SDA) Nomenclature system. SDA nomenclature allows feedstock flexibility among natural fats and oils and their petroleum-synthetic equivalents, but it only applies to the 35 species listed in the SDA Nomenclature guidance.

The fact that source is included in the identity of UVCB substances is a problem that extends beyond triglycerides. Mixed biobased hydrocarbon streams from pyrolysis or reforming may be identical to petroleum refinery streams that are listed on the Inventory, but if those petroleum streams include “petroleum,” “crude oil,” or other similar terms in either the name or the definition, manufacturers of the biobased equivalent cannot use the petroleum-based names for TSCA purposes.

Source-specific nomenclature, like TSCA itself, is showing its age. The biobased sector needs to engage with EPA and with Congress to be sure that TSCA nomenclature is made more flexible, either through rulemaking or statutory reform, with a more source-agnostic system that will enable novel sources to be incorporated into the existing supply chains without unnecessary burden on all stakeholders. A system where equivalence to existing identities can be determined as part of the PMN review could be an effective way to ease adoption of biobased products into the supply chain without compromising risk to human health and the environment.

Up next in Part II: TSCA requirements for feedstocks, catalysts, and intermediates.

Rich Engler is a Senior Policy Advisor with Bergeson & Campbell, P.C. and The Acta Group. Previously, he worked at EPA for 17 years, where he was a staff scientist in the Office of Pollution Prevention and Toxics. At EPA, he reviewed numerous chemicals under TSCA, led the Green Chemistry Program, including the Presidential Green Chemistry Challenge, and worked on many other projects, including the Risk-Screening Environmental Indicators and Trash-Free Waters. 

Prior to joining EPA, Rich taught organic chemistry at the University of San Diego. He holds a Ph.D. in physical organic chemistry from the University of California, San Diego.