5 CCR 1001-34
DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT REGULATION NUMBER 30 TOXIC AIR CONTAMINANTS 5 CCR 1001-34 [Editor’s Notes follow the text of the rules at the end of this CCR Document.] _________________________________________________________________________ Outline of Regulation PART A General Provisions for Toxic Air Contaminants PART B Identification of Priority Toxic Air Contaminants PART C Statements of Basis, Specific Statutory Authority and Purpose Appendices, by Part _________________________________________________________________________ Pursuant to Colorado Revised Statutes § 24-4-103(12.5), any materials incorporated by reference are available for public inspection during normal business hours, or copies may be obtained at a reasonable cost from the Air Quality Control Commission, 4300 Cherry Creek Drive South, Denver, Colorado 80246- 1530. Any federal material incorporated by reference is also available through the United States Government Printing Office, online at www.govinfo.gov. Materials incorporated by reference are those editions in existence as of the date indicated and do not include any later amendments. PART A General Provisions for Toxic Air Contaminants I. General Provisions I.A. Definitions I.A.1. “Hazardous air pollutant” (HAP) means an air pollutant through inhalation or other routes of exposure, a threat of adverse human health effects (including, but not limited to, substances which are known to be, or may reasonably be anticipated to be carcinogenic, mutagenic, teratogenic, neurotoxic, which cause reproductive dysfunction, or which are acutely or chronically toxic) or adverse environmental effects whether through ambient concentrations, bioaccumulation, deposition, or otherwise and which has been listed pursuant to section 112 of the federal act or § 25-7-109.3, C.R.S., as provided in § 25-7-103(13), C.R.S. (2024). I.A.2. “Priority toxic air contaminant” (PTAC) means a toxic air contaminant that may pose a risk of harm to public health, as provided in § 25-7-109.5(1)(f), C.R.S. (2024).
PART B Identification of Priority Toxic Air Contaminants I. Identification of Priority Toxic Air Contaminants I.A. As of January 17, 2025, the Commission identifies the following five priority toxic air contaminants, as also reflected in Appendix A.
I. Adopted: January 17, 2025 This Statement of Basis, Specific Statutory Authority, and Purpose complied with the requirements of the Colorado Administrative Procedure Act § 24-4-103(4), C.R.S., the Colorado Air Pollution Prevention and Control Act §§ 25-7-110, -110.5, and -110.8 C.R.S. (the State Air Act), and the Air Quality Control Commission’s (Commission) Procedural Rules, 5 Code Colo. Reg. § 1001-1. Basis In 2022, the General Assembly adopted House Bill (HB) 22-1244 (Public Protections from Toxic Air Contaminants), now codified primarily in § 25-7-109.5, C.R.S. § 25-7-109.5(6)(a)(I), C.R.S. directs the Commission to adopt rules that identify up to five priority toxic air contaminants (PTACs) by no later than April 30, 2025.
The Commission adopted a new Regulation Number 30 to meet the statutory directive at § 25-7- 109.5(6)(a)(I), C.R.S.
Specific Statutory Authority The State Air Act, specifically § 25-7-105(1), C.R.S., directs the Commission to promulgate such rules and regulations as are consistent with the legislative declaration set forth in § 25-7-102, C.R.S. and that are necessary for the proper implementation and administration of the State Air Act. § 25-7-109.5(6)(a)(I), C.R.S. directs the Commission to, by no later than April 30, 2025, identify up to five PTACs, considering:
I. Existing data concerning toxic air contaminants gathered through the Air Pollution Control Division (Division) Monitoring programs;
II. Data reported to the Division concerning emissions of toxic air pollutants;
III. Data reported to the federal toxics release inventory pursuant to 42 U.S.C. § 11023 and data prepared by the federal environmental protection agency's (EPA) air toxics screening assessment (AirToxScreens) program;
IV. Any other relevant data submitted to the Commission during the rule-making process concerning the amount of emissions and concentrations of toxic air contaminants in the ambient air of the state, including data collected through community-led monitoring programs; and V. Input from the scientific community.
Purpose As directed in § 25-7-109.5(6)(a)(I), C.R.S., the Commission adopted a new Regulation Number 30, which identifies five PTACs.
Regulation Number 30 Regulatory Language and Outline In Part A, General Provisions for Toxic Air Contaminants, the Commission adopted necessary definitions. In Part B, Identification of Priority Toxic Air Contaminants, Section 1, the Commission identified five PTACs.
Prioritization Framework The Commission adopted the five PTACs based on a prioritization framework developed by Colorado Department of Public Health and Environment (CDPHE) staff. This prioritization framework involved input from a scientific community technical working group, feedback from stakeholders, and months of research and data analysis, consistent with the requirements set forth in § 25-7-109.5(6)(a)(I), C.R.S. CDPHE staff collected data on statewide toxic air contaminants (TACs), following requirements in § 25-7- 109.5(6)(a)(I), C.R.S. These data sources included existing data concerning toxic air pollutants gathered through Division monitoring programs, data reported to the Division concerning emission of toxic air pollutants, data reported to or prepared by the EPA for the Toxic Release Inventory (TRI) and EPA’s AirToxScreen program, data collected through community-led monitoring programs, and input from the scientific community. These data sources were supplemented with additional monitoring and modeled data suggested by the scientific community technical working group, and data from the first annual reporting cycle of TAC that was required under § 25-7-109.5(4)(a), C.R.S. Using these data to understand the prevalence of different TACs in Colorado, staff then estimated cancer and non-cancer health risks using pollutant-specific toxicity values. These toxicity values were adjusted slightly during the rulemaking process based on updates that EPA made to its regional screening level (RSL) table in November 2024. Toxicity values are numerical indicators of the potential of a chemical to cause harmful effects and are specific to either cancer or non-cancer health impacts. Cancer and non- cancer health impacts are analyzed separately due to differences in dose-response modeling. Chemicals that cause non-cancer impacts are generally considered to have a threshold below which there are no health effects. By contrast, even small exposures to chemicals that cause cancer are thought to increase a person’s cancer risk.
Non-cancer health impacts are expressed as a Hazard Quotient (HQ). A HQ below 1 indicates that negative health effects are not expected. If the HQ exceeds 1, adverse health effects may be more likely to occur. Cancer health impacts i.e., the increased potential to develop cancer–is expressed as the increased risk of cancer per 1 million people.
For pollutants with adequate monitored or modeled data from the sources described above, the Division calculated screening level risk estimates for both cancer and non-cancer health impacts using the pollutant-specific toxicity values. This analysis showed a measure of health risk based on modeled or monitored ambient concentrations of certain TACs.
CDPHE staff then assigned groupings to TACs using a tiered health risk approach. For the purposes of prioritization, CDPHE used a cancer screening risk level of greater than or equal to 1 in 1 million excess cancer cases. For non-cancer health impacts, CDPHE used a screening risk level of a HQ of greater than or equal to 0.1. The threshold of a HQ of 0.1 is commonly used during screening when multiple chemicals are present. Though negative health impacts are not expected for a single chemical at an HQ of 0.1, it is used in screening in order to account for exposures to multiple chemicals that could act together to cause negative health impacts.
Once the pollutants meeting or exceeding the screening levels for modeled or monitored data were identified, staff considered additional factors in analyzing those pollutants. The Division compared the existing monitored or modeled data from the list of approximately 40 pollutants to the various reporting program datasets it had available (e.g., APEN, National Emissions Inventory (NEI) and TRI). The emissions reported in each dataset were weighted by a relative toxicity factor from the EPA Risk Screening Environmental Indicator (RSEI) model. These toxicity-weighted emissions were ranked from highest to lowest. All of the top 11 toxicity-weighted pollutants in each dataset were also identified in the list of 40 pollutants screened in the aforementioned risk thresholds, further supporting the potential prioritization of pollutants on that list.
For modeled risk, staff evaluated the predominant source of each TAC that fell into this category. TACs predominantly from sources that the Commission has authority to regulate were prioritized over TACs predominantly resulting from sources outside the scope of Commission rules (e.g., biogenic sources and wildfires). Separately, staff limited its assessment for modeled risk to non-mobile sources. This was done to narrow the list of potential TACs to no more than five PTACs, consistent with the statutory direction. Staff determined that excluding mobile source emissions was reasonable because § 25-7-109.5(7)(b)(II), C.R.S. specifically directs the Commissions to consider stationary source emissions in developing emission control regulations for PTACs and because § 25-7-109.5(8)(a), C.R.S. specifically directs the Division to assess its needs to administer a PTAC stationary source permitting program. Additionally, Colorado is currently pursuing several incentive and regulatory programs to reduce emissions from mobile sources, such as state enterprises created under Senate Bill 21-260, including the Clean Fleet Enterprise, Nonattainment Area Pollution Mitigation Enterprise, Clean Transit Enterprise and Community Access Enterprise, the Colorado Clean Cars Program and the Advanced Clean Trucks and Heavy-Duty Low NOx rules. These mobile source programs are anticipated to begin achieving significant reductions of TACs as a co-benefit. These modeled risks were then ranked from highest to lowest for cancer risk and non-cancer HQ.
Over three meetings with the scientific community technical working group, staff posed questions and gathered feedback from group members on the prioritization framework. Specifically, the group provided insight into quantifying risk from monitored and modeled data, how to develop a risk-based framework, use of different toxicity values, and which health effects to focus on during prioritization of TACs. Group members also supplemented additional scientific research and sources of monitoring and modeling data to be used in the prioritization framework.
Using the prioritization framework, staff identified three PTACs that had an estimated HQ over 1 for non- cancer health impacts or over 100 in 1 million cancer risk. These were acrolein, ethylene oxide, and hydrogen sulfide. Staff then considered populations exposed to TACs that ranked among the top five modeled risks for cancer or non-cancer to assess risk based on how many people may be impacted by these pollutants, including how many of those people are located in a disproportionately impacted community as prioritized in the Air Quality Control Commission (AQCC) Regulation (Reg.) 3 Disproportionately Impacted Community Layer in Version 1.0 of Colorado EnviroScreen. The Division used this layer because it was designed to prioritize areas that are relevant for stationary source regulations, and staff focused on stationary source emissions in selecting the PTAC. Using census block and block group averages from AirToxScreen 2020 data, staff estimated the number of people exposed to TACs from non-mobile, anthropogenic sources of emissions. This analysis allowed staff to identify three additional pollutants, formaldehyde, benzene, and hexavalent chromium, for prioritization, over others with similar risk characterizations, given the exposure and risk posed to more people state-wide. The Commission prioritized formaldehyde over acrolein based on this population exposure analysis and feedback and data submitted during the rulemaking process. Identification of Five Priority Toxic Air Contaminants Applying the foregoing analysis, the Commission adopted benzene, chromium compounds (hexavalent), ethylene oxide (EtO), formaldehyde and hydrogen sulfide (H2S) as the initial five PTACs. Benzene Benzene emissions met the screening threshold of over 1 in 1 million cancer risk based on the estimated health risk from both monitoring and modeling data. Benzene is a federally designated HAP. In Colorado, based on the EPA AirToxScreen modeling results for human-caused, non-mobile sources, and considering adjustments made to correct for inventory data used in the AirToxScreen modeling, benzene was among the top five highest cancer risk based on AirToxScreen 2019 and among the top six highest cancer risk based on AirToxScreen 2020 modeling results. In addition to this pollutant ranking among the highest modeled cancer risk pollutants, staff further prioritized this pollutant based on population-level exposures, finding there are approximately 180 people, of which 157 are located in a disproportionately impacted community, exposed to benzene in Colorado at levels with an estimated risk of at least 10 excess cancer cases per million people. There are also 1.4 million people, of which 697,000 are located in a disproportionately impacted community, exposed to benzene in Colorado at levels with an estimated risk of between 1 and 10 excess cancer cases per million people. In addition to the modeled cancer risk, the available annual average monitoring data for over 100 different monitored benzene concentrations is in the 1-10 per million excess cancer cases range for the most part. Specifically, the available monitoring data ranges from 1 to 27 per million excess cancer cases, with a mean of approximately 6 per million excess cancer cases. Benzene is a volatile organic compound (VOC), a class of chemicals released into the air from numerous sources, including vehicle exhaust, cleaning products, paint, and gasoline. In Colorado, oil and gas operations, along with other industrial activities, are significant sources of benzene emissions. Benzene is naturally present in crude oil and natural gas, and significant emissions occur during various stages of the handling of crude oil and natural gas. During the extraction process, benzene is released when oil and gas is brought to the surface, as the volatile compounds are exposed to the atmosphere. In the refining process, crude oil is separated into different products, releasing benzene during the breakdown of hydrocarbons. Similarly, when natural gas is processed for sale, benzene may be released during various processing steps. Storage and transportation of oil and gas also contribute to benzene emissions, especially if containment systems are not properly sealed, allowing volatile compounds to escape into the air. Additionally, benzene emissions occur from combustion of wood including residential burning and forest fires. Chronic exposure to benzene may cause disorders in the blood by affecting bone marrow. Aplastic anemia (a risk factor for a specific type of leukemia), excessive bleeding, and damage to the immune system (by changes in blood levels of antibodies and loss of white blood cells) may develop. Benzene exposure may cause structural and numerical chromosomal abnormalities. Animal and human studies have provided evidence that exposure to benzene may impact reproductive and developmental organs. The EPA classifies benzene as a carcinogen. Long term exposure to benzene can cause leukemia. There have also been studies that show an association between benzene exposure and types of lymphoma, myeloma, and lung cancers. Chromium Chromium compounds, hexavalent, also called hexavalent chromium, had an estimated excess cancer risk that met the screening threshold of over 1 in 1 million cancer risk based on the estimated health risk from modeled data after corrections to inventory data were made. Chromium compounds are federally designated HAPs and hexavalent chromium is a state designated HAP under § 25-7-109.3(5)(a) C.R.S. In Colorado, based on the EPA AirToxScreen modeling results for human-caused, non-mobile sources, and considering adjustments made to correct for inventory data used in the AirToxScreen modeling, hexavalent chromium was among the top five highest cancer risk based on AirToxScreen 2019 and 2020. Staff further prioritized this pollutant based on population-level exposures, finding that, based on the updated RSL values and EPA AirToxScreen 2020 modeling results for human-caused, non-mobile sources, approximately 33 people, all of which are located in a disproportionately impacted community, are exposed to hexavalent chromium at levels with an estimated risk of at least 10 excess cancer cases per million people and 7,800 people, of which 5,400 are located in a disproportionately impacted community, are exposed to hexavalent chromium at levels with an estimated risk of between 1 and 10 excess cancer cases per million people. This population exposure is the next highest after benzene among pollutants that had the top five highest modeled cancer or non-cancer health impacts, with the exception of formaldehyde.
Hexavalent chromium is generated when chromium compounds combine with other elements during industrial processes. These compounds are widely used in various manufacturing applications, such as in the production of metal alloys (i.e., stainless steel, brass, aluminum, or plastic) and in decorative chromium electroplating for car parts, furniture, hydraulic cylinders, and aircraft landing gears. Hexavalent chromium is also utilized in anodizing operations to prevent corrosion in aerospace components and their machined parts. Hexavalent chromium is released into the air during the combustion of oil, natural gas, coal, and in certain manufacturing processes, including cement and hazardous waste facilities. Cigarette smoke and industrial emissions from metal processing are additional sources. Furthermore, it is released from plating tanks through control devices and vents, windows, and doors as fugitive emissions during chrome plating operations.
Coal-fired power plants are the largest emitter in Colorado followed by fabricated metal product manufacturing, particularly processes used in electroplating operations and abrasive blasting of metal parts. The sources driving the highest risk from hexavalent chromium are these smaller sources due to their proximity to more densely populated areas. Chronic exposure to hexavalent chromium may cause respiratory effects, including perforations and ulcerations of the septum, bronchitis, decreased pulmonary function, pneumonia, asthma, and nasal itching or soreness. There is limited evidence that exposure to hexavalent chromium may result in complications during pregnancy and childbirth. Epidemiological studies of workers have found clear associations between chromium exposure and lung cancer. EPA, DHHS, and IARC have all classified hexavalent chromium as a carcinogen. Ethylene Oxide Ethylene oxide (EtO) emissions had an estimated cancer risk exceeding 100 in 1 million exposed people, based on the estimated health risk from both modeling data, including only human-caused, non-mobile sources, and monitoring data in the state. EtO is a federally designated HAP. EtO is a colorless gas, used in making a range of products such as antifreeze, textiles, plastics, detergents, and adhesives. EtO is also used to sterilize equipment and plastic devices, often medical equipment, unable to be cleaned by steam. In Colorado, sterilizers located in commercial sterilization facilities, or supporting other industrial processes or research and development applications, are the largest contributors to EtO emissions. The storage of sterilized materials is also one source of emissions. While the EPA finalized a regulation on April 5, 2024, see 89 Fed. Reg. 24090, to reduce emissions from four existing commercial sterilizers as well as any new sterilizer facility that should be built in the state, there are other sources of EtO in the state that are not covered by EPA’s rule. Additionally, this PTAC had the highest estimated cancer risk of any pollutant in the state. Chronic exposure to EtO may cause eye, skin, and respiratory irritation, as well as impacts to the nervous system, including headache, nausea, memory loss, and numbness. EtO exposure may cause an increased rate of miscarriages as well as other reproductive effects. The EPA classifies EtO as a carcinogen. EtO has been shown to cause lymphoid cancer and breast cancer in humans.
Formaldehyde Formaldehyde met the screening threshold of over 1 in 1 million cancer risk based on the estimated health risk from both monitoring and modeling data. Additionally, formaldehyde met the screening threshold of an HQ over 0.1 from both monitoring and modeling data. Formaldehyde is a federally- designated HAP. Formaldehyde is a colorless, flammable gas at room temperature with a strong, pungent odor and is highly reactive and is classified as a VOC. In Colorado, based on the EPA AirToxScreen modeling results for human-caused, non-mobile sources, and considering adjustments made to correct for inventory data used in the AirToxScreen modeling, formaldehyde was among the top five highest cancer risk based on AirToxScreen 2019 and AirToxScreen 2020 modeling results. Formaldehyde also had the sixth highest HQ for AirToxScreen 2020 modeling results. In addition to this pollutant ranking among the highest modeled cancer risk pollutants, staff further prioritized this pollutant based on population-level exposures, finding there are approximately 400,000 people, of which 2,000 are located in a disproportionately impacted community, exposed to formaldehyde from human-caused, non-mobile sources in Colorado at levels with an estimated risk of at least 10 excess cancer cases per million people. There are also 4.15 million people, of which 93,000 are located in a disproportionately impacted community, exposed to formaldehyde in Colorado at levels with an estimated risk of between 1 and 10 excess cancer cases per million people. Some of this same population, approximately 229,000 people, of which 2,000 are located in a disproportionately impacted community, is also exposed to an HQ between 0.1 and 0.6. In addition to the modeled cancer risk, the available annual average monitoring data for 13 different monitored formaldehyde observations ranges from 15 to 57 per million excess cancer cases, with a mean of approximately 38 per million excess cancer cases. For monitored HQ, the available data is in the range of 0.17 - 0.63 with a mean of 0.41 HQ. In Colorado, formaldehyde is a notable byproduct of incomplete combustion including the burning of organic matter, like wood (e.g., wildfires, residential wood combustion, or open burning), other combustion associated with industrial operations and electricity generation, motor vehicle exhaust, and decaying organic matter. Much of the combustion occurring in the industrial sector is associated with oil and gas extraction and production including combustion engines used for drilling or compression activities or flaring, as well as combustion to operate glycol dehydrators and regeneration units at natural gas processing plants. Formaldehyde is also emitted from surface coating or solvent usage and during the production or of composite wood products. Secondary formation is also a significant source of formaldehyde emissions, resulting from atmospheric reaction between VOCs in the atmosphere. Chronic exposure to formaldehyde may cause respiratory symptoms, sensitization leading to asthma and contact dermatitis, neurological effects, and eye, nose, and throat irritation. Occupational and animal studies have shown epithelial lesions from chronic inhalation exposure. There is limited evidence that pulmonary functions may also be adversely affected. EPA has classified formaldehyde as a probable human carcinogen. Occupational studies have found limited evidence of associations between formaldehyde exposure and increased incidence of lung and nasopharyngeal cancer. The International Agency for Research on Cancer (IARC) and Department of Health and Human Services (DHHS) have classified formaldehyde as a human carcinogen.
Hydrogen Sulfide Hydrogen Sulfide emissions had an estimated health risk from monitoring data that exceeded a HQ of 1 for non-cancer health impacts. Estimated health risk from modeling data, including only human-caused, non-mobile sources, met the screening criteria of a HQ over 0.1. Hydrogen Sulfide is not a HAP under federal or state law, but it is a “covered air toxic,” as defined at § 25-7-141(2)(b), C.R.S. Since Hydrogen Sulfide is not a HAP, it is not reported to the EPA National Emission Inventory (NEI) or used in EPA AirToxScreen modeling analysis. The scientific community technical working group provided feedback to expand the data sources considered to include CDPHE modeling studies to address this gap. Staff developed dispersion modeling conducted in a selected 20-kilometer area near Commerce City North Denver to assess the health risk from this pollutant. This area was selected for modeling because it has the highest concentration of reported hydrogen sulfide emissions in the state. Additionally, 3 other stationary monitors had monitoring data available for hydrogen sulfide that were above the screening criteria of a HQ of 0.1.
Hydrogen sulfide is a colorless gas released from both natural sources, such as the decay of organic matter, and human activities, including waste disposal (wastewater treatment and landfilling), industrial processes like petroleum refining, natural gas processing, wastewater treatment, roofing and asphalt material manufacturing, meat processing, gas processing plants and compressions stations, renewable natural gas processing from biogas and molybdenum mining. Chronic exposure to hydrogen sulfide may cause low blood pressure, headache, nausea, loss of appetite, weight loss, eye-membrane inflammation, loss of muscle control, chronic cough, and psychological disorders. Low concentrations can result in irritation of the eyes, nose, and throat, while higher concentrations may lead to more severe respiratory issues, headaches, dizziness, and chronic conditions.
As resources allow, the Commission encourages the Division to move forward with identifying additional PTACs sooner than 2029. In addition to other toxins the Division deems deserving of further study after consultation with scientific experts, stakeholders, and the affected public, we would encourage the Division to also study polycyclic organic matter (including benzo(a)pyrene), ultrafine particles, and radionuclides for potential identification as a PTAC.
The Commission recognizes both the importance and complexity of this statutorily-directed rulemaking and notes that it will be followed by subsequent rulemakings to adopt health-based standards and control measures, as well as the opportunity for designating additional PTACs in the future. In selecting these five initial PTACs, the Commission relied upon the information in the record, while being responsive to community input about compounds of concern to their lived experience. The Commission was statutorily constrained to a maximum of five toxic air contaminants in designating the initial set of PTACs. The Commission believes that the Division appropriately filtered its potential list of initial PTACs to focus first on those from stationary sources. However, there is no numeric limit in the statutes on how many TACs can be designated as PTACs throughout the life of this program. The Commission encourages the Division to not limit its study and analysis just to TACs associated with stationary sources but to also consider those associated with mobile sources to the extent supported by data.
Additional Considerations There are no direct federal requirements that correspond with the new rule. However, to the extent the new rule could be construed to exceed or differ from any related requirements of federal law, the Commission provides the following additional statement, consistent with § 25-7-110.5(5)(a), C.R.S.:
(I) Any federal requirements that are applicable to this situation with a commentary on those requirements;
(II) Whether the applicable federal requirements are performance-based or technology-based and whether there is any flexibility in those requirements, and if not, why not; The federal requirement to list hazardous air pollutants is not performance-based or technology- based. EPA adds pollutants which present, or may present, through inhalation or other routes of exposure, a threat of adverse human health or environmental effects.
(III) Whether the applicable federal requirements specifically address the issues that are of concern to Colorado and whether data or information that would reasonably reflect Colorado's concern and situation was considered in the federal process that established the federal requirements; The federal requirement to list hazardous air pollutants do not specifically address Colorado’s statutory directive to identify up to five priority toxic air contaminants.
(IV) Whether the proposed requirement will improve the ability of the regulated community to comply in a more cost-effective way by clarifying confusing or potentially conflicting requirements (within or cross-media), increasing certainty, or preventing or reducing the need for costly retrofit to meet more stringent requirements later;
(V) Whether there is a timing issue which might justify changing the time frame for implementation of federal requirements;
(VI) Whether the proposed requirement will assist in establishing and maintaining a reasonable margin for accommodation of uncertainty and future growth; The identification of five priority toxic air contaminants does not directly establish additional requirements on the regulated community and, therefore, does not impact future growth.
(VII) Whether the proposed requirement establishes or maintains reasonable equity in the requirements for various sources;
(VIII) Whether others would face increased costs if a more stringent rule is not enacted; The identification of five priority toxic air contaminants does not directly establish additional requirements on the regulated community.
(IX) Whether the proposed requirement includes procedural, reporting, or monitoring requirements that are different from applicable federal requirements and, if so, why and what the “compelling reason” is for different procedural, reporting, or monitoring requirements; The identification of five priority toxic air contaminants does not directly establish additional procedural, reporting, or monitoring requirements.
(X) Whether demonstrated technology is available to comply with the proposed requirement; The identification of five priority toxic air contaminants does not directly establish additional requirements on the regulated community.
(XI) Whether the proposed requirement will contribute to the prevention of pollution or address a potential problem and represent a more cost-effective environmental gain; The identification of five priority toxic air contaminants does not directly establish additional requirements on the regulated community.
(XII) Whether an alternative rule, including a no-action alternative, would address the required standard.
Findings of Fact § 25-7-110.8, C.R.S., requirements do not apply to this rulemaking because the adopted rule is not directly intended to reduce air pollution. To the extent § 25-7-110.8, C.R.S. does apply to this rulemaking, after considering all the information in the record, the Commission hereby makes the determination that:
(I) The rule is based upon reasonably available, validated, reviewed, and sound scientific methodologies, and the Commission has considered all information submitted by interested parties.
(II) The rule is not intended, directly, to address a reduction in air pollution, or, in the alternative, is administrative in nature.
(III) Evidence in the record supports the finding that the rule provides benefits that justify the costs to government to implement the rule, and the rule does not result in any cost to the regulated community or public.
(IV) The rule has no regulatory impact on any person, facility, or activity and, therefore, the analysis under § 25-7-110.5(4), C.R.S. is not required. Additionally, the rule is not intended, directly, to achieve a reduction in air pollution.
(V) The rule does not directly result in air quality benefits. APPENDICES, BY PART Part B:
Appendix A: Priority Toxic Air Contaminants CAS Number Toxic Air Contaminant Date Identified 71432 Benzene 1/17/2025 18540299 Chromium Compounds, Hexavalent 1/17/2025 75218 Ethylene Oxide 1/17/2025 50000 Formaldehyde 1/17/2025 7783064 Hydrogen Sulfide 1/17/2025 _________________________________________________________________________ Editor’s Notes History New rule eff. 03/17/2025.