The U.S. Environmental Protection Agency (EPA) currently requires reporting on the Toxics Release Inventory (TRI) for 196 per- and poly-fluoroalkyl substances (PFAS) on an individual chemical basis. In early October, the EPA proposed a new TRI rule that
promotes the debated concept of PFAS categories. If promulgated as written, the new rule could trigger added compliance challenges.
What are PFAS?
PFAS, sometimes referred to as “forever chemicals,” are commonly used, long-lasting substances that encompass thousands of individual molecules. These chemicals are applied in a myriad of consumer and industrial products because of their
unique waterproofing and grease/stain-repelling properties. Since they tend to break down slowly, can be absorbed and accumulate internally, and remain in the environment for a long time, many are detected in the blood of humans and wildlife.
Studies have shown that some PFAS may be harmful to human health and the environment at sufficiently high exposures. Accordingly, state and federal agencies continue to develop PFAS control regulations such as Toxics Release Inventory (TRI).
The National Defense Authorization Act (NDAA) first
added 172 PFAS to TRI in 2019. In defining PFAS for TRI, EPA adopted the Toxic Substances Control Act (TSCA) Section 8(a)(7) definition based on structural formulas. The NDAA also created a framework for automatically adding PFAS to TRI every
year. Outside this framework, PFAS that meet the selection criteria can also be added to TRI via rulemaking.
TRI PFAS substances include industrial chemicals, pesticides, and pharmaceuticals. Under the Emergency Planning and Community Right-to-know Act (EPCRA), facilities that manufacture, process, or otherwise use PFAS above a threshold of 100 pounds (lbs) per year must report how much they release into the environment on an annual basis.
EPA’s Toxics Release Inventory PFAS Proposal
EPA’s proposed rule would add 16 more individual PFAS (Table 1) that would be subject to Toxics Release Inventory (TRI) reporting starting in 2025.
The rule also designates all TRI PFAS as chemicals of “special concern.” Starting
with the 2024 reporting year, this designation would nullify the current de minimis exemption of 0.1% for perfluorooctanoic acid (PFOA), which EPA deems a carcinogen (hence the lower limit), and 1% for other PFAS found in mixtures. The exemption
currently concerns not only TRI data reporting obligations, but also notifications for value chain suppliers — businesses that provide resources to companies that use them to make products — alerting their clients to the presence of
PFAS in their materials.
Lastly, the proposed rule would create 15 de novo
PFAS categories (Table 2), each encompassing a “family” of compounds.
The rule suggests reclassifying 35 individually listed PFAS as part of these chemical categories. In addition to the 16 individual TRI PFAS, the categories would add another 64 to TRI. This means that there would be 80 new PFAS substances in 2025 subject to TRI regulations under the proposed regulation.
Table 1. Proposed Individually Listed TRI PFAS Additions for RY24.
| No. | Simplified Identifier | CAS | Toxicity Rationale |
1 | Broflanilide
| 1207727-04-5 | Chronic Human Health
Effect on the Environment
|
| 2 | MeFBSA | 68298-12-4 | Chronic Human Health |
| 3 | MeFBSE | 34454-97-2 | Chronic Human Health
|
| 4 | HFCPE | 1892-03-1 | Effect on the Environment |
| 5 | Uoroethyl sulfonyl ethane sulfonamide lithium salt | 132843-44-8 | Chronic Human Health |
| 6 | 6:2 FTOH | 647-42-7 | Chronic Human Health |
| 7 | Fulvestrant | 129453-61-8 | Effect on the Environment |
| 8 | Hexaflumuron | 86479-06-3 | Effect on the Environment |
| 9 | Uoromethoxymethyl Pentane | 132182-92-4 | Chronic Human Health |
| 10 | PFTrDA | 72629-94-8 | Effect on the Environment |
| 11 | EEA-NH4 | 908020-52-0 | Chronic Human Health |
| 12 | MeFBSEA | 67584-55-8 | Chronic Human Health |
| 13 | Pyrifluquinazon | 337458-27-2 | Chronic Human Health |
| 14 | Tetraconazole | 112281-77-3 | Effect on the Environment |
| 15 | Triethoxy fluorooctyl silane | 51851-37-7 | Chronic Human Health |
| 16 | HFPO | 428-59-1 | Chronic Human Health |
CAS – Chemical Abstracts Service
Challenges of Regulating PFAS by Category
The EPA has considered regulating PFAS by class in the past and is developing other category schemes. In fact, the agency already regulates other chemicals on the Toxics Release Inventory (TRI) list, such as nonylphenols, in this way. Those in favor of
this approach argue that it would better manage the human and environmental risks linked with exposure to PFAS because it targets multiple rather than individual chemicals at once.
But while complying with regulations on individual chemicals is relatively straightforward, following rules applied to groups of chemicals could be more complicated.
The proposed TRI PFAS categories are separate from ongoing efforts by EPA and other agencies to define PFAS categories or “classes” for other regulatory and research activities. The TRI PFAS categories focus on the acid form of “parent”
PFAS as well as environmentally relevant moieties, each with their own Chemical Abstracts Service (CAS) identifier (a “moiety” is a part of a molecule that is given a name because it is identified as a part of other molecules as well).
The specific moieties included in TRI PFAS categories are salts, acyl/sulfonyl halides, and anhydrides.
For compliance, users can generally match the CAS number of their PFAS compounds against the TRI CAS subject to reporting. For example, let’s examine Category 3 devoted to HFPO-DA (Gen X). The listing of parent CAS 13252-13-6 and category members
CAS 2062-98-8, 62037-80-3, 67118-55-2, and 67963-75-1, is helpful and will facilitate matching with chemical inventories of known substances. But it may be difficult to distinguish these specific chemical characteristics in mixtures from environmental
releases and waste. What’s more, analytical testing likely wouldn’t be able to detect the exact chemical forms that TRI targets. This could get even more complicated if value chain suppliers have to share TRI information through supplier
notifications. The proposed rule is silent on this issue.
Table 2. Proposed Toxics Release Inventory (TRI) PFAS Chemical Categories and Category Members.
| Category | Parent Identifier
| CAS
| Category Members
|
| 1 | 9Cl-PfF3ONS | 756426-58-1 | 73606-19-6 |
| 2 | 11Cl-Pf3OUdS | 763051-92-9 | 83329-89-9 |
| 3 | HFPO-DA/GenX* | 13252-13-6 | 2062-98-8
62037-80-3*
67118-55-2
67963-75-1 |
| 4 | PFBS* | 375-73-5 | 375-72-4
29420-49-3* 36913-91-4 60453-92-1 68259-10-9 70225-18-2 131651-65-5 220689-12-3 507453-86-3 |
| 5 | PFBA* | 375-22-4 | 335-42-2*
336-59-4 375-16-6 2218-54-4* 2966-54-3* 3794-64-7 10495-86-0* 73755-28-9 45048-62-2* |
| 6 | PFDA* | 13252-13-6 | 307-38-0
3108-42-7* 3830-45-3* 942199-24-8 |
| 7 | PFDoA* | 307-55-1 | 3793-74-6 1456735-80-0 |
| 8 | PFHxS* | 355-46-4 | 423-50-7
3871-99-6* 55120-77-9 68259-08-5* 70225-16-0* 82382-12-5 109065-55-6 |
| 9 | PFHxA* | 307-24-4 | 308-13-4
336-02-7 355-38-4 335-53-5 2923-26-4 3109-94-2 21615-47-4 |
| 10 | PFNA* | 375-95-1 | 558-95-2
4149-60-4 21049-38-7 21049-39-8 52447-23-1 228407-54-3 |
| 11 | 6:2 FTS | 27619-97-2 | 2043-57-4
27619-89-2 27619-94-9 59587-38-1 59587-39-2 1807944-82-6 |
| 12 | PFOA* | 335-67-1 | 335-64-8
335-66-0* 335-93-3* 335-95-5* 2395-00-8* 3825-26-1* 17125-58-5 17125-60-9 33496-48-9 68141-02-6* 98065-31-7 |
| 13 | PFOS* | 1763-23-1 | 307-35-7*
423-92-7 2795-39-3* 4021-47-0 29081-56-9* 29457-72-5* 56773-42-3* 70225-14-8 91036-71-4 111873-33-7 |
| 14 | PFPrA | 422-64-0 | 356-42-3
378-76-7 378-77-8 422-59-3 422-61-7 |
| 15 | PFUnA | 2058-94-8 | 4234-23-5
30377-53-8 60871-96-7 97163-17-2 942199-03-3 |
*already on TRI
1acid
2salts, acyl/sulfonyl halides, and/or anhydrides
How would Toxics Release Inventory (TRI) PFAS Reporting Change?
EPA estimates that more than 1,100 additional TRI reporting forms would be needed under the proposed rule. While individually listed substances would be reported as they are currently with each substance on a separate form, each category would require
one form combining the uses and quantities of all PFAS member chemicals. Facilities would first need to calculate the total weight of all chemicals that fall under a category for each threshold activity, such as manufacturing and processing, and
compare the totals to the applicable thresholds. If a facility exceeds reporting thresholds, it would be required to report the aggregated quantities of releases and other waste management activities of the substances in the chemical category
concerned. EPA’s new rule continues to cite a general reporting threshold of 100 lbs for the combined quantity of all PFAS in a category, as well as individually listed substances. The category approach, although counterintuitive, will result
in double counting of total mass reported when a given compound falls into multiple PFAS or non-PFAS categories. This has been EPA’s prescribed and long-standing approach.
What’s Next
EPA is accepting
public comments on the proposed rule through Dec. 9. Specifically, the agency is seeking feedback on
the proposed categories and their substance groupings, as well as alternate methods for identifying and proposing Toxics Release Inventory (TRI) chemicals and reporting thresholds. After the public comment period, the agency may consider feedback
when issuing a final and sometimes revised rule. The final rule will be published in the
Federal Register and in the EPA’s official
docket on
Regulations.gov later this year. The rule is expected to take effect on January 1, 2025.
To remain compliant with PFAS regulations, facilities subject to TRI reporting should identify, track, and collect data on the 196 currently listed PFAS substances. They should also understand the new and existing
reporting requirements and the elimination of
de minimis exemptions.
