Regulatory Developments

EPA Proposes SNURs for Eight Renewable Chemical Substances

April 23, 2013 PRINT

On April 18, 2013, the U.S. Environmental Protection Agency (EPA) proposed significant new use rules (SNUR) under the Toxic Substances Control Act (TSCA) for eight chemical substances that were the subject of premanufacture notices (PMN) P-11-327, P-11-328, P-11-329, P-11-330, P-11-331, P-11-332, P-12-298, and P-12-299, the first six of which are renewable, biobased chemical substances manufactured by KiOR, Inc. This memorandum explains why the proposed SNURs for the biobased chemical substances raise novel questions and warrant careful review and comment.


KiOR is a manufacturer of renewable biobased fuels. It converts non-food biomass (wood, forestry residuals, and related materials) into renewable crude oil for processing into gasoline, diesel, and fuel oil. The six chemical substances at issue in the rule are defined by EPA as "complex mixtures" that will be used as a distillation feedstock after hydrotreatment, as a feedstock, as a blend-stock for conventional fossil fuels, and used in a manner comparable to gas oil as it is currently used in industry.

EPA issued direct final SNURs for these six (and other) chemicals on November 2, 2012. 77 Fed. Reg. 66149. According to EPA, these PMNs were assessed based on the "toxic components within their mixture" and the most important and primary component present in these six complex mixtures is benzene. EPA identified concerns "for oncogenicity, immunosuppression, and skin sensitization to workers exposed to the PMN substances" and negotiated a risk-based consent order under TSCA Section 5(e)(1)(A)(i) and Section 5(e)(1)(A)(ii)(I) based on a finding that these substances "may present an unreasonable risk of injury to human health and the environment" thus requiring the use of protective measures by workers to limit exposures. The rulemaking is intended to apply the "section 5(e) SNURs" on the PMN substances if manufactured or imported by others. The SNURs designate as a "significant new use" the absence of the protective measures required in the corresponding consent order.

The final SNURs would require persons who intend to manufacture, import, or process any of the chemical substances for an activity that is designated as a significant new use to notify EPA at least 90 days before commencing that activity. The required notification would provide EPA the opportunity to evaluate the intended use and, if necessary, to prohibit or limit the activity before it occurs. After receiving notices of intent to submit adverse comments on the direct final SNURs, EPA withdrew them on December 21, 2012. 77 Fed. Reg. 75566.

In the April 18, 2013, Federal Register notice, EPA proposes the SNURs as is required under 40 C.F.R. Section 721.160(c)(3)(ii) and notes again that PMN substances P-11-327, P-11-328, P-11-329, P-11-330, P-11-331, and P-11-332 are subject to a "risk-based" consent order under TSCA Section 5(e)(1)(A)(ii)(I) where EPA determined that activities associated with the substances may present unreasonable risk to human health or the environment. EPA states that it is proposing the "so-called 'section 5(e) SNURs'" on these PMN substances pursuant to 40 C.F.R. Section 721.160, and are "based on and consistent with the provisions in the underlying consent order." As with the direct final rule, the proposed SNURs would designate as a "significant new use" the absence of the protective measures required in the corresponding consent order.

EPA also proposed SNURs for PMN substances P-12-298 and P-12-299, which are not subject to any TSCA Section 5(e) consent order and are not discussed further here.

SNUR Provisions

The proposed SNUR designates as a "significant new use" the absence of the following protective measures required by the consent order for PMN substances P-11-327, P-11-328, P-11-329, P-11-330, P-11-331, and P-11-332:

  1. Use of personal protective equipment including dermal protection when there is potential dermal exposure and a National Institute for Occupational Safety and Health (NIOSH)-certified respirator with an assigned protection factor (APF) of at least 10,000, or compliance with a New Chemical Exposure Limit (NCEL) of 0.32 microgram per cubic meter (mg/m3) as an eight-hour time-weighted average when there is potential inhalation exposure;
  2. No use of the substances resulting in surface water concentrations exceeding five parts per billion (ppb) of the combination of these PMN substances; and
  3. Establishment and use of a hazard communication program.

The Federal Register notice provides the following information regarding recommended testing:

EPA has determined that a combined chronic toxicity/carcinogenicity test (OPPTS Test Guideline 870.4300); a daphnid chronic toxicity test (OPPTS Test Guideline 850.1300); and fish early-life stage toxicity test (OPPTS Test Guideline 850.1400) would help characterize the human health and environmental effects of the PMN substances. The order does not require submission of the testing at any specified time or production volume. However, the order's restrictions on manufacture, import, processing, distribution in commerce, use, and disposal will remain in effect until the order is modified or revoked by EPA based on submission of that or other relevant information.


There are several aspects of these proposed KiOR SNURs that warrant discussion.

EPA based its hazard assessment of the PMN substances on the presence of benzene, an existing chemical component in the complex mixture. According to comments submitted on the direct final rule, EPA's decision to base its hazard assessment on benzene as opposed to the "toxicology data for conventional petroleum gasoline and diesel fuels" is not consistent with "long-standing practice in the TSCA program." That it may not align with past practice yields some anomalous results.

First, even though the benzene concentration in the P-11-329 PMN substance contains less benzene (<2%) than conventional gasoline blends (3.4%), the PMN substance is the subject of a TSCA Section 5(e) consent order with the attendant worker protection requirements set forth above. None of these requirements applies to conventional gasoline blends, which can be expected to contain higher benzene levels.

Second, as the comment suggests, there is no indication that EPA considered the available data on chemically comparable (i.e., analogous) petroleum feedstocks or fuels in assessing the hazards of the new chemicals, choosing instead to focus on a specific component. This seems to be at odds with EPA's practice in approaching complex mixtures under the High Production Volume (HPV) Challenge Program where EPA relied on test data on the mixture (Gasoline Blending Streams Category), not on the individual components. EPA's decision also seems not to take advantage of what could be a rich source of potentially relevant test data given testing otherwise required on fuels under, for example, Clean Air Act Section 211 or conducted under other regulatory auspices.

Third, because of the EPA requirements in the Section 5(e) order and in the proposed SNUR, the identification of hazards as reported on the Material Safety Data Sheets (MSDS) for fuel blends containing the PMN substances will necessarily be different than the MSDSs prepared on essentially identical petroleum-based blends containing conventional substances. This will invite confusion and impose unnecessary burdens on processors of the blends for no good reason.

Another important aspect of the proposed SNUR relates to the apparent inclusion of new language in the provisions relating to workplace protection. Not included in the direct final rule was this language:

When determining which persons are reasonable likely to be exposed as required for § 721.63(a)(1) and (a)(4), engineering control measures (e.g., enclosure or confinement of the operation, general and local ventilation) or administrative control measures (e.g., workplace policies and procedures) shall be considered and implemented to prevent exposure, where feasible.

The inclusion of language requiring companies to use engineering controls, in addition to requiring more traditional worker personal protective equipment (PPE) "where feasible," is apparently becoming standard language in SNURs and likely future Section 5(e) orders. While industry understands and applies a hierarchy of controls in managing occupational exposures, this change by EPA raises many issues. On the procedural side, EPA's use of this new language (which seemingly did not appear in the Section 5(e) orders because, if it had, the language would have been included in the direct final SNUR) should have been discussed in the proposed SNUR notice and should have been the subject of comment.

On the implementation side, the language is ambiguous and could be read to require "where feasible" the implementation of engineering control measures. At the least, the language would benefit from greater explanation and a clearer articulation of EPA's policy change in this regard.


For a variety of reasons, interested parties, particularly biobased chemical and biofuel manufacturers and processors, may wish to comment on the proposed SNURs. EPA's decision to rely upon benzene as the driver for the PMN substances' hazard assessment, despite the availability of potentially significant numbers of studies on comparable petroleum-based complex mixtures, may be both inconsistent with past EPA practice when assessing such complex mixtures and causing these PMN substances to be subject to SNUR provisions despite the fact that they may actually contain less benzene than conventional fuel blends. In fact, if the presence of benzene is the driver in determining hazards and risks of the new chemicals, seemingly the presence of lower levels of benzene in these mixtures should have been seen and been valued by EPA as a health, environmental, and pollution prevention benefit of the new chemicals rather than as the basis for enhanced TSCA regulation.

In preparing comments on the proposed SNURs, stakeholders have a terrific opportunity to expand upon the unintended consequences of EPA's review, and the ironically and regrettable adverse impacts the hazard assessment may have on the commercialization of these renewable biobased chemicals. Substances subject to SNURs are plainly more commercially challenged than chemicals not so encumbered. These unintended consequences spill over into the hazard communication anomalies noted above and invite confusion and impose unnecessary burdens. A more detailed discussion of the application of TSCA to biobased chemicals can be found here.

On a more generic level, the new language included in the proposed SNUR relating to engineering control measures should be the subject of robust discussion. The inclusion of this language in the proposed rule and its absence in the direct final rule present an excellent opportunity to comment on the actual language, the apparent new EPA policy to include this language routinely in SNURs and Section 5(e) orders, and the significant policy implications of this approach.

Comments on the proposed SNURs are due May 20, 2013.

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