The U.S. Environmental Protection Agency (EPA or the Agency) is taking final action to revise the manner for applying the threshold planning quantities (TPQs) for those extremely hazardous substances (EHSs) that are non-reactive solid chemicals in solution. This revision allows facilities subject to the Emergency Planning requirements that have a non-reactive solid EHS in solution, to first multiply the amount of the solid chemical in solution on-site by 0.2 before determining if this quantity equals or exceeds the lower published TPQ.

This change is based on data that shows less potential for non-reactive solid chemicals in solution to remain airborne and dispersed beyond a facility's fence line in the event of an accidental release. Previously, EPA assumed that 100% of non-reactive solid chemicals in solution could become airborne and dispersed beyond the fenceline in the event of an accidental release.  This rule is effective April 23, 2012.

Who is affected by this final rule?

Entities that would be affected by this final rule are those organizations and facilities subject to section 302 of the Emergency Planning and Community Right-to-Know Act (EPCRA) and its implementing regulations found in 40 CFR part 355, subpart B--Emergency Planning. To determine whether your facility is affected by this action, you should carefully examine the applicability provisions at 40 CFR part 355. If you have questions regarding the applicability of this action to a particular entity, consult the person listed in the preceding FOR FURTHER INFORMATION CONTACT section.

What is the statutory authority for this final rule?

This final rule is being issued under the Emergency Planning and Community Right-to-Know Act of 1986 (EPCRA), which was enacted as Title III of the Superfund Amendments and Reauthorization Act of 1986 (Pub. L. 99-499), (SARA). The Agency relies on EPCRA section 328 for general rulemaking authority.

List of Abbreviations and Acronyms

ARF--Airborne Release Fraction
CAS--Chemical Abstracts Service
CBI--Confidential Business Information
CERCLA--Comprehensive Environmental Response, Compensation, and
Liability Act
CFR--Code of Federal Regulations
EHS--Extremely Hazardous Substance
EO--Executive Order
EPA--Environmental Protection Agency
EMA--Emergency Management Agency
EPCRA--Emergency Planning and Community Right-to-Know Act of 1986
FR--Federal Register
HCS--Hazard Communication Standard
ICR--Information Collection Request
LEPC--Local Emergency Planning Committee
LOC--Level of Concern
MSDS--Material Safety Data Sheet
NFPA--National Fire Protection Association
NRC--National Response Center
NTTAA--National Technology Transfer and Advancement Act of 1995
OMB--Office of Management and Budget
OEM--Office of Emergency Management (within EPA)

What is the background of this final rule?

Title III of SARA (EPCRA) establishes authorities for emergency planning and preparedness, emergency release notification reporting, community right-to-know reporting, and toxic chemical release reporting. It is intended to encourage state and local planning for, and response to releases of hazardous substances and to provide the public, local governments, fire departments, and other emergency officials with information concerning potential chemical hazards present in their communities. The implementing regulations for emergency planning, emergency release notification, and the chemicals subject to these regulations are codified in 40 CFR part 355. The implementing regulations for community right-to-know reporting (or hazardous chemical reporting) are codified in 40 CFR part 370. Subtitle A of EPCRA establishes the framework for local emergency planning. The statute requires that EPA publish a list of extremely hazardous substances (EHSs). The EHS list was established by EPA to identify chemical substances that could cause serious irreversible health effects from accidental releases (52 FR 13378, April 22, 1987). The Agency was also directed to establish a threshold planning quantity (TPQ) for each extremely hazardous substance.

Under EPCRA section 302, a facility that has an EHS on-site in excess of its TPQ must notify the State Emergency Response Commission (SERC) and Local Emergency Planning Committee (LEPC), as well as participate in local emergency planning activities. Under EPCRA section 304, the facility owner or operator must report accidental releases of EHSs and hazardous substances listed under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) in 40 CFR 302.4 in excess of the reportable quantity (RQ) to their LEPC and SERC, and to the National Response Center if the chemical is a CERCLA hazardous substance.

Under ECPRA sections 311 and 312, facilities that have either (1) a hazardous chemical present at or above 10,000 pounds or (2) an EHS present at or above its TPQ or 500 pounds--whichever is the lesser, are required to submit an Emergency and Hazardous Chemical Inventory form and a Material Safety Data Sheet (MSDS) for that chemical to their SERC, LEPC and local fire department. A chemical is hazardous as defined under the Hazard Communication Standard (HCS) of the Occupational Safety and Health Act (OSHA).

In a July 26, 1990 Federal Register notice (55 FR 30632), EPA added definitions necessary to designate Indian Tribes as the implementing authority of the emergency planning reporting and notification requirements and hazardous inventory reporting requirements. Under 40 CFR 355.61 and 40 CFR 370.66, when a facility is located in Indian Country, SERC means the Emergency Response Commission for the Tribe under whose jurisdiction the tribe is located. Such a Tribal Emergency Response Commission is known as a TERC.

The purpose of the EHSs list is to focus initial efforts in the development of state and local contingency plans. Inclusion of a chemical on the EHSs list does not mean state or local communities should ban or otherwise restrict use of a listed chemical. Rather, such identification indicates a need for the community to undertake a program to investigate and evaluate the potential for accidental exposure associated with the production, storage or handling of the chemical at a particular site and develop a chemical emergency response plan around those risks.

Regulatory Background

The list of EHSs and their TPQs are codified in 40 CFR part 355, Appendices A and B. EPA first published the EHSs list and corresponding TPQs along with the methodology for determining the TPQs as an interim final rule on November 17, 1986 (51 FR 41570). In the final rule of April 22, 1987 (52 FR 13378), EPA made a number of revisions. Among other things, the final rule republished the EHSs list, added four new chemicals, and revised the methodology for some TPQs. The final rule also defined TPQs for EHS solids in solution, based on comments on the 

interim final rule. Details of the methodology used in determining whether to list a substance as an EHS and deriving the TPQs are found in the November 1986 and April 1987 Federal Register notices and in the technical support documents,\1\ all found in the docket for this rulemaking.
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\1\ Threshold Planning Quantities Technical Support Document, 4-7-87. Chemicals That Were Assigned Threshold Planning Quantities Different From the Calculated Index Value, 4-7-87. Reactive Solids Whose Threshold Planning Quantities Should Be Less than 10,000 Pounds, 4-7-87. Changes Made to Threshold Planning Quantities Between Proposed Rule and Final Rule, 4-7-87. Technical Support Document for Determination of Levels of Concern, 11-11-86.
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Development of Existing TPQs

The TPQs were initially assigned based on a ranking scheme using a Level of Concern (LOC) based on acute toxicity and the potential for airborne dispersion. The TPQ methodology is described in detail in the ``Threshold Planning Quantities Technical Support Document'' dated April 7, 1987, which can be found in the docket for this rulemaking. For each chemical, a ranking index was calculated which equaled the LOC divided by an air dispersion factor (V). Chemicals were assigned TPQs of 1, 10, 100, 500, 1000 or 10,000 pounds based on the order of magnitude ranges of the index values. For gases, V = 1, while for liquids, V was based on a volatilization model using the molecular weight and boiling point of the chemical.

Solid EHS chemicals with a particle size less than 100 microns in diameter, molten solids, solids in solution, and solids with a National Fire Protection Association (NFPA) reactivity rating of 2, 3, or 4 were assigned a V equal to 1. If the EHS solid did not have a particle size less than 100 microns, was not molten or handled in solution form, and did not have an NFPA reactivity rating of 2, 3, or 4, then the EHS chemical was assigned a TPQ of 10,000 pounds, which corresponds to the highest index value. Solids with a NFPA reactivity rating of 2, 3, or 4 are denoted with an ``a'' in the Notes column of the EHSs list. For solids in molten form, before applying the TPQ, the amount of chemical on-site at any time is multiplied by an adjustment factor of 0.3 to conservatively account for the maximum volatilization of the spilled molten substance that is likely to take place.

Changes to EHS List and TPQs

EPA has since amended the EHSs list and deleted 51 chemicals. Ten chemicals were deleted based on the request of petitioners and the remaining 41 chemicals were deleted as a result of Agency review. The chemicals were deleted because they did not meet the toxicity criteria for the list and/or were originally listed in error. Petitions requesting the deletion of two chemicals, paraquat dichloride (which is discussed below) and isophorone diisocyante have been denied. Isophorone diisocyanate was not deleted from the EHSs list because its inhalation toxicity met the EHSs listing criteria.

EPA has also changed the TPQs for some of the EHSs. In the April 22, 1987 final rule, EPA reduced the TPQs for 36 substances, while it raised the TPQs for 12 substances based on updated acute toxicity data. Since then, EPA has lowered the TPQ for muscimol because of a typographical error in a prior rulemaking; EPA has raised the TPQ for isophorone diisocyanate because it was mistakenly based on a physical state of reactive solid, when it is actually a liquid; and EPA has denied a petition to raise the TPQs for azinphos methyl and fenamiphos.

Summary of Proposed Rule of April 15, 2011

In the proposed rule of April 15, 2011 (76 FR 21299), EPA proposed that facilities who are subject to the emergency planning notification requirements under section 302 of EPCRA, and who have a non-reactive solid EHS in solution on-site, should multiply the amount of the non-reactive solid chemical (in solution form) by 0.2 before determining if this reduced quantity equals or exceeds the lower published TPQ. This change was proposed based on data in the literature that shows less potential for non-reactive solid chemicals in solution to remain airborne beyond a facility's fenceline in the event of an accidental release. This change affects not just paraquat dichloride solution, but all EHS solid chemicals in solution, except reactive solids. The application of a reducing factor to the amount of non-reactive EHS solids in solution before comparison to its TPQ is similar to how facilities apply the TPQs for EHSs that are molten solids, except that for molten solids the factor is 0.3.\2\ EPA also defined solution to be any aqueous or organic solutions, slurries, viscous solutions, suspensions, emulsions, or pastes.

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\2\ The amount present on-site for EHSs that are in a molten form is calculated by multiplying the weight of the chemical by 0.3 to determine if the lower TPQ is met or exceeded.
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However, this change will not apply to the 12 solid EHS chemicals that are reactive solids (denoted with ``a'' in the ``Notes'' column in Appendix A or B of 40 CFR part 355). Reactive solids are more likely than other solids to be dispersed into the air due to the energy or heat created from their reactivity with water or air. The explanation for not assigning a 10,000 pounds TPQ to each of the reactive solids is discussed in the document, "Reactive Solids Whose Threshold Planning Quantities Should Be Less Than 10,000 Pounds," April 7, 1987, which can be found in the docket to this rulemaking. Previously, EPA had assumed that 100% of non-reactive EHS solid chemicals in solution could become airborne in the event of an accidental release. Review of the literature data for accidental releases of liquid aerosols shows that no more than 20% of the release is expected to remain airborne. The data is from a 1994 U.S. Department of Energy (USDOE) report \3\ (available in the docket) on the airborne release fraction (ARF) from experimental liquid aerosol releases involving metal salt solutions for a wide variety of release scenarios. EPA based the 0.2 factor on the scenario with the highest release potential in order best to serve the purposes of emergency planning. A summary of the USDOE aerosol release scenarios with the highest ARFs are listed in a table in the April 15, 2011 proposed rule (76 FR 21299). A more detailed discussion, along with the alternative approaches considered, can be found in the April 15, 2011 proposed rule and in the "Technical Support Document for Revised TPQ Method for EHS Solids in Solution" in the docket for this rule.

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\3\ DOE Handbook, Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear Facilities. December 1994. U.S. Department of Energy, Washington, DC 20585. DOE-HDBK-3010-94. Volume I--Analysis of Experimental Data and Volume II--Appendices.
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EPA's revised TPQ methodology for non-reactive EHS solids in solution and supporting data was peer reviewed and the technical support document was revised based on peer review comments. The results of the peer review and response to peer review comments are found in a separate document, "Peer Review of Technical Support Document for Revised TPQ Method for EHS Solids in Solution," which is available in the docket to this rulemaking. A summary of the peer reviewer's comments and EPA responses to them are presented in the April 15, 2011 proposed rule (76 FR 21299).

What is the scope of this final rule?

This final rule revises the manner for applying the TPQ for the 157 non-reactive EHS chemicals that are handled as solids in solution. These 157 chemicals appear with two TPQs, (the higher TPQ is 10,000 pounds) in Appendix A and B of 40 CFR part 355. The 12 solid EHS chemicals that are reactive solids are noted by footnote "a" in Appendix A and B of 40 CFR part 355, and are not affected by this final rule. Definitions of reactive and non-reactive solids, which were explained in the preamble of the proposed rule, have also been added to the regulations in 40 CFR 355.61 for greater clarity.

Solid EHSs (except reactive solids) have a TPQ of 10,000 pounds or a specified lower TPQ, for particular forms. For purposes of complying with the emergency planning notification requirements of section 302 of EPCRA, facilities should multiply the amount of EHS chemical handled as a non-reactive solid in solution on-site by 0.2 before determining if this amount equals or exceeds the established lower TPQ. If the amount of the non-reactive EHS solids in solution on-site multiplied by 0.2 does not equal or exceed the lower TPQ for that solid EHS, then the facility is not subject to the EPCRA section 302 emergency planning notification requirements for that substance. This amount includes only the weight of the chemical and not the solvent or other chemicals in solution. The amount of non-reactive EHS solids in solution may be determined by multiplying the weight percent of the EHS solids in solution in a particular container by the weight of the total solution. Solutions include aqueous or organic solutions, slurries, viscous solutions, suspensions, emulsions, and pastes.

Additionally, EPA has also revised the regulations for 40 CFR 355.16(c) to be applicable only to molten non-reactive solids. That is, the factor of 0.3 to be multiplied by the amount of a molten solid on-site before comparing to the lower TPQ should only be used for non-reactive solids in molten form, not reactive solids in molten form. Reactive solids are more likely to be dispersed into the air due to the energy or heat created from their reactivity with water or air and their TPQs were developed taking these factors into account.

Additionally, the methodology of applying TPQs for non-reactive EHS solids in solution or non-reactive molten solids does not affect the reporting requirements for sections 311 and 312 of EPCRA (40 CFR part 370). Regulations under 40 CFR 370.10 state that an EHS is present at a facility if the ``amount of EHS present at any one time'' is equal or greater than 500 pounds or the TPQ, whichever is lower. The reducing factor of 0.2 for non-reactive EHS solids in solution or (0.3 for non-reactive EHS molten solids) is not to be used for compliance with hazardous chemical reporting. Therefore, EPA has amended the text of 40 CFR 355.16 (b) and (c) to clarify that the reduction in quantity for the amount of non-reactive EHS solids in solution and for the amount of non-reactive EHS solid in molten form present at a facility does not apply for reporting requirements under 40 CFR 370.10, which covers MSDS and hazardous chemical inventory reporting. That is, facilities must not use the reduction in quantity on-site to determine the "amount present at one time" for reporting under 40 CFR 370.10.

The reason why the reducing factors are to be used for emergency planning notification under 40 CFR part 355 and not under hazardous chemical reporting under 40 CFR part 370 are explained below. Emergency planning notification under section 302 helps LEPCs identify those facilities whose accidental releases pose risks to the surrounding community so they can develop emergency plans that identify the location and number of affected populations, evacuation or shelter-in-place procedures, etc. On the other hand, sections 311 and 312 of EPCRA require submission of MSDSs and an on-site inventory of hazardous chemicals to help emergency responders assess how to respond to an emergency release or fire. In particular, responders need the amounts, manner of storage and locations of the chemical on-site, the chemical and physical properties, hazard ratings, toxicity information and incompatibilities of the chemical, as well as measures needed to contain the spill or fire at the facility in order to know how to respond to an emergency. In addition, they need to know what type of protective equipment is needed to protect them from exposure, not only airborne, but also dermal exposure.

Emergency release notification requirements under EPCRA section 304 also are not affected by this final action. Section 304 requires facilities to notify the community emergency coordinator for the LEPC of any area likely to be affected by the release and the SERC of any area likely to be affected by the release (defined in 40 CFR 355.61) at or above the reportable quantity (RQ) of any EHS or CERCLA hazardous substance. If the chemical released is a CERCLA hazardous substance, the release must also be reported to the National Response Center (NRC). The RQ is not the same as the TPQ. TPQs are based on acute mammalian toxicity and potential for airborne dispersion. RQs, on the other hand, are developed using several criteria, including aquatic toxicity, mammalian toxicity, ignitability, reactivity, chronic toxicity, potential carcinogenicity, biodegradation, hydrolysis, and photolysis (50 FR 13468, April 4, 1985).

Applying a TPQ for an Non-Reactive EHS Solid in Solution

Facilities with a non-reactive EHS solid in solution should apply the 0.2 factor only to the amount of EHS solid present, not the total weight of the solution. As an example, a facility has 4,000 pounds of a solution of 37% by weight paraquat dichloride on-site. Therefore, this solution contains 1,480 pounds of paraquat dichloride (0.37 x 4,000 pounds). The facility would multiply 1,480 pounds by 0.2, which equals 296 pounds. This amount is then compared to the TPQ for paraquat dichloride, which is 10 pounds. Because this amount exceeds the 10 pounds TPQ, the facility is required to comply with the emergency notification requirements of section 302 of EPCRA. As another example, a facility has 10 gallons (gal) of a solution of 37% by weight paraquat dichloride on-site. The density of the solution is 9.33 pounds per gallon. Therefore, this solution contains 34.5 pounds of paraquat dichloride (10 gal x 9.33 lb/gal x 0.37). The facility would multiply 34.5 pounds by 0.2, which equals 6.9 pounds. This amount is then compared to the TPQ for paraquat dichloride, which is 10 pounds. Because this amount is less than the 10 pounds TPQ, the facility is not required to comply with the emergency notification requirements of section 302 of EPCRA.

Facilities that handle both the powdered and solution forms of a particular non-reactive solid EHS will have to consider the quantities of each form and the particle size to determine whether they exceed a TPQ. Below are several examples of how to apply the revised TPQ methods in various cases.\4\

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\4\ For these examples, the EHS is not paraquat dichloride, but an unspecified non-reactive solid EHS that has a lower TPQ of 500 pounds and a higher TPQ of 10,000 pounds.
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Non-reactive solid in solution exceeds lower TPQ, powder below 10,000 pounds. A facility has on-site 5,000 pounds of a pure EHS powder with a particle size equal to or greater than 100 microns, which is less than the 10,000 pounds TPQ. However, they also have 1,000 gallons of a 35% by weight non-reactive EHS solid in solution with a density of 9 pounds per gallon. The amount of solids in solution on-site is 3,150 pounds (1000 gallons x 9 pounds per gallon x 0.35). Multiplying the 3,150 pounds of solid in solution by 0.2 equates to 630 pounds, which exceeds the lower TPQ of 500 pounds. Thus, the facility must report under section 302 of EPCRA based on exceeding the lower TPQ for the non-reactive solid in solution form.

Non-reactive solid in solution below lower TPQ, powder exceeds 10,000 pounds. A facility has on-site 11,000 pounds of a pure EHS solid powder with a particle size equal to or greater than 100 microns, which is more than the 10,000 pounds TPQ. They also have 2,000 gallons of a 10% by weight non-reactive EHS solid in solution with a density of 9 pounds per gallon. The amount of solids in solution on-site is 1,800 pounds (2,000 gallons x 9 pounds per gallon x 0.10). Multiplying the 1,800 pounds of solid in solution by 0.2 equates to 360 pounds, which is less than the lower TPQ of 500 pounds. Thus, the facility must report under section 302 of EPCRA based on exceeding the 10,000 pounds TPQ for the solid in powder form.

Non-reactive solid in solution below lower TPQ, powder below 10,000 pounds. A facility has 5,000 pounds of a pure EHS solid powder with a particle size equal or greater than 100 microns, which is less than the 10,000 pounds TPQ. They also have 1,500 gallons of a 15% by weight non-reactive EHS solid in solution with a density of 9 pounds per gallon.

The amount of solids in solution on-site is 2,025 pounds (1.500 gallons x 9 pounds per gallon x 0.15). Multiplying the 2,025 pounds of solid in solution by 0.2 equates to 405 pounds, which is less than the lower TPQ of 500 pounds. Thus, the facility is not required to report under section 302 of EPCRA because it does not exceed the lower 500 pounds TPQ for the non-reactive solids in solution form or the 10,000 pounds TPQ for the powder with a particle size greater than 100 microns.

Powdered product less than 100 microns, processed into solution. If the same amount of solid EHS powder were involved as the same scenarios above, except the powder has a particle size less than 100 microns, then the lower 500 pounds TPQ would apply to the powder instead of 10,000 pounds. If either the amount of powder or non-reactive solids in solution exceeds the lower TPQ, the facility would be required to report under section 302 of EPCRA.