Air Toxics

The type of information the agencies are requesting is based on the air permit or registration issued to a facility. Facilities should review this page entirely before beginning the data collection and estimation process.
  • List of emission units (equipment) and activities that emit air toxics (see link to list below). Identification of emission units or activities that emit air toxics should not be limited to what is listed in the permit but should include all potential sources of air toxic emissions.  
  • List of annual production and fuel and/or material usage rates (both calendar year 2016 and projected maximum year) for each emission unit and activity. Use the projected maximum annual production and process rates that are used to calculate plant site emissions limits for permits.
  • Material balance information using Safety Data Sheets (formerly Material Safety Data Sheets) and/or Technical Data Sheets for solvent or coating materials used in any process.
  • Operating schedule (hours/day, days/year, seasonal variability) for the facility and/or emission units and activities.

In addition, the agencies are asking all facilities with Title V, Standard and Simple Air Contaminant Discharge Permits to submit:

  • List of air toxic pollutants and emission factors for each emission unit and activities.
  • Name of resource used to obtain air toxics emission factors or methodologies used to estimate emissions (e.g., AP-42 or WebFIRE, California Air Toxic Emission Factors, etc.)
  • Emission estimates including material balance.
​DEQ recommends the following process to begin preparing this request:

  • Catalog the usage of raw materials and fuels, production outputs, emission units/activities, and control devices
  • Focus on those activities that relate to production at the facility, rather than activities relating to maintenance

Gain a comprehensive understanding for the full range of air toxics emitting activities at the facility by undertaking an inventory to identify:
  • the raw materials used at the facility
  • the fuels used at the facility
  • the products produced at the facility
  • all regulated and unregulated air toxics pollutant-emitting emission units/activities
  • the rates at which the emission units/activities operate
  • all air toxic pollutants emitted by the emission units/activities
  • air toxics emission factors or estimation methodologies to estimate emissions
  • all existing control devices

Where to find this information

There are several places to begin collecting the information requested above. The following topics provide information and resources to assist in identifying potential emission units and activities that emit air toxics and where to find production information, emission factors, and estimation methodologies.

Area Source Registrants and Basic and General Air Contaminant Discharge Permit facilities:

Both agencies will estimate emissions for these facilities and is asking for information to assist in the calculations. The agencies encourage facilities to start with what they know; specifically, emission units and activities already identified in air permits that emit or potentially emit air toxics. Please note that some emission units and activities may be exempt from this request. Facilities should review the Categorically Insignificant Activities to Exclude section before starting the data collection process.

This information can be found in records retained onsite including current air permits and permit review reports. Also, any documents used to prepare permit applications, emission detail sheets, emission estimates for annual reports, and Safety Data Sheets are potential resources. For what facilities do not know, this website provides additional resources to help identify emission units and activities that may not be included in air permits but should be included in this request.

A reporting matrix is provided below to help facilities determine what information to report for this request. The document is organized by permit type and shows what information is reported annually to the agencies and any additional information needed from facilities to estimate air toxics emissions. The specific information requested can be found in the reporting forms and reporting matrix provided below. The information requested is not limited to what is identified in the reporting matrix. Facilities should include information for emission units and activities not found in the matrix or permits. All facilities need to include both annual production and fuel and material usage rates for 2016 calendar year and projected maximum year. Facilities are expected to submit information regardless of any annual reporting thresholds indicated in permits.

Simple and Standard Air Contaminant Discharge Permit and Title V facilities:

The agencies are asking these facilities to estimate their own emissions for this request including material balance calculations. (Please see Quantifying Emissions and Material Balance sections below.) The burden is on the facility to find emission factors or estimation methodologies through various resources such as trade associations, manufacturer data and specification sheets, or use engineering judgement to estimate emissions. The agencies do not expect any facility to perform source tests to measure air toxics at this time but welcomes the data because it provides more accurate estimates. Additional resources are provided below on this webpage to find emission factors and methodologies to estimate emissions.

Facilities should start with what they know; specifically, emissions units and activities already identified in air permits that emit or potentially emit air toxics. Please note that some emission units and activities may be exempt from this request. Before beginning the data collection process facilities should review the section Categorically Insignificant Activities to Exclude.

These facilities are required to submit air toxics information for U.S. Environmental Protection Agency’s (USEPA) federal list of 187 hazardous air pollutants with permit applications for new permits, permit renewals, or permit modifications. This information is submitted using permit application forms such as AQ403 or ED606 and emission detail sheets. In addition, some facilities are now required to provide Toxic Release Inventory reports with AQ403 or ED606 forms for permit applications.

Additional information can be found in records retained onsite including current air permits and permit review reports, emission detail sheets, emission estimates for annual reports, and Safety Data Sheets to fulfill this request. All facilities need to update existing emissions information, add new information as requested, and add new pollutants from the list of approximately 630 air toxic contaminants that are applicable to their industrial processes.

This is a modified list from OAR 340-200-0020 and Title 12, Section 12-005 of categorically insignificant activities for facilities to exclude from this information request. "Categorically insignificant activity" in this case is emitting activities principally supporting the source or the major industrial group. Emissions from these types of activities are considered insignificant when identifying emission units and activities that emit air toxics at a facility.

  1. Evaporative and tailpipe emissions from on-site motor vehicle operation;
  2. Any individual distillate oil, kerosene or gasoline burning equipment with a rating less than 0.4 million Btu/hour;
  3. Any individual natural gas or propane burning equipment with a rating less than 2.0 million Btu/hour;
  4. Distillate oil, kerosene, gasoline, natural gas or propane burning equipment brought on site for six months or less for maintenance, construction or similar purposes, such as but not limited to generators, pumps, hot water pressure washers and space heaters, provided that any such equipment that performs the same function as the permanent equipment, must be operated within the source's existing PSEL;
  5. Office activities;
  6. Food service activities;
  7. Janitorial activities;
  8. Personal care activities;
  9. Groundskeeping activities including, but not limited to building painting and road and parking lot maintenance;
  10. On-site laundry activities;
  11. On-site recreation facilities;
  12. Instrument calibration;
  13. Maintenance and repair shop;
  14. Air cooling or ventilating equipment not designed to remove air contaminants generated by or released from associated equipment;
  15. Refrigeration systems with less than 50 pounds of charge of ozone depleting substances regulated under Title VI, including pressure tanks used in refrigeration systems but excluding any combustion equipment associated with such systems;
  16. Bench scale laboratory equipment and laboratory equipment used exclusively for chemical and physical analysis, including associated vacuum producing devices but excluding research and development facilities;
  17. Temporary construction activities;
  18. Warehouse activities;
  19. Accidental fires;
  20. Air vents from air compressors;
  21. Air purification systems;
  22. Continuous emissions monitoring vent lines;
  23. Demineralized water tanks;
  24. Pre-treatment of municipal water, including use of deionized water purification systems;
  25. Electrical charging stations;
  26. Fire brigade training;
  27. Instrument air dryers and distribution;
  28. Process raw water filtration systems;
  29. Pharmaceutical packaging;
  30. Fire suppression;
  31. Blueprint making;
  32. Routine maintenance, repair, and replacement such as anticipated activities most often associated with and performed during regularly scheduled equipment outages to maintain a plant and its equipment in good operating condition, including but not limited to steam cleaning, abrasive use, and woodworking;
  33. Electric motors;
  34. Storage tanks, reservoirs, transfer and lubricating equipment used for ASTM grade distillate or residual fuels, lubricants, and hydraulic fluids;
  35. On-site storage tanks not subject to any New Source Performance Standards (NSPS), including underground storage tanks (UST), storing gasoline or diesel used exclusively for fueling of the facility's fleet of vehicles;
  36. Natural gas, propane, and liquefied petroleum gas (LPG) storage tanks and transfer equipment;
  37. Pressurized tanks containing gaseous compounds;
  38. Vacuum sheet stacker vents;
  39. Emissions from wastewater discharges to publicly owned treatment works (POTW) provided the source is authorized to discharge to the POTW, not including on-site wastewater treatment and/or holding facilities;
  40. Log ponds;
  41. Stormwater settling basins;
  42. Fire suppression and training;
  43. Paved roads and paved parking lots within an urban growth boundary;
  44. Hazardous air pollutant emissions in fugitive dust from paved and unpaved roads except for those sources that have processes or activities that contribute to the deposition and entrainment of hazardous air pollutants from surface soils;
  45. Health, safety, and emergency response activities;
  46. Emergency generators and pumps used only during loss of primary equipment or utility service due to circumstances beyond the reasonable control of the owner or operator, or to address a power emergency, provided that the aggregate horsepower rating of all stationary emergency generator and pump engines is not more than 3,000 horsepower. If the aggregate horsepower rating of all stationary emergency generator and pump engines is more than 3,000 horsepower, then no emergency generators and pumps at the source may be considered categorically insignificant;
  47. Non-contact steam vents and leaks and safety and relief valves for boiler steam distribution systems;
  48. Non-contact steam condensate flash tanks;
  49. Non-contact steam vents on condensate receivers, deaerators and similar equipment;
  50. Boiler blowdown tanks;
  51. Industrial cooling towers that do not use chromium-based water treatment chemicals;
  52. Ash piles maintained in a wetted condition and associated handling systems and activities;
  53. Uncontrolled oil/water separators in effluent treatment systems, excluding systems with a throughput of more than 400,000 gallons per year of effluent located at the following sources:
    1. Petroleum refineries;
    2. Sources that perform petroleum refining and re-refining of lubricating oils and greases including asphalt production by distillation and the reprocessing of oils and/or solvents for fuels; or
    3. Bulk gasoline plants, bulk gasoline terminals, and pipeline facilities;
  54. Combustion source flame safety purging on startup;
  55. Broke beaters, pulp and repulping tanks, stock chests and pulp handling equipment, excluding thickening equipment and repulpers;
  56. Stock cleaning and pressurized pulp washing, excluding open stock washing systems; and
  57. White water storage tanks.

Emission estimates should be based on actual 2016 calendar and projected maximum year production and fuel and/or material usage rates. Projected maximum emissions should be based on the maximum production and process rates used to establish plant site emission limits for a facility’s permit. The following list is a presumptive hierarchy of the types of information that best approximate actual and projected maximum emissions but each individual case may be different:

  1. Existing air toxic emission factor in current permit detail sheet.
  2. Source test data
  3. Source test data from similar equipment
  4. Material balances
  5. Fuel sampling and analysis
  6. Trade or technical association data (e.g., National Council for Air and Stream Improvement, National Particleboard Association, etc.)
  7. DEQ emission factors
  8. California (SCAQMD) or Washington State (Ecology) emission factors
  9. Compilation of Air Pollutant Emission Factors (AP-42)
  10. Airs Facility Subsystem (AFS) Source Classification Codes and Emission Factor Listing
  11. Engineering judgment based on sound assumptions about the source type, industry, or site- specific conditions

When emission factors are used to calculate emissions, the following approach explains the above hierarchy in more detail and should be used to improve the consistency and correctness of the projected maximum emission rates and current actual emissions:

  • Use all site specific source test data whenever available, even if it is only one test, provided that it is representative of the process during the time period under consideration. If there is only one test, that test result (that is, the average of the three test runs) should be used for the emission factor. If there is more than one test, the average of all the test results should be used. No correction, cushion (20%), or standard deviation should be added to the emission factor.
  • If representative source-specific data cannot be obtained, emissions information from equipment vendors, particularly emission performance guarantees or actual test data from similar equipment is typically a better source of information for permitting decisions than AP-42, trade or technical association data or DEQ or other regulatory agency emission factors.
  • If no emissions information from equipment vendors or actual test data from similar equipment is available, emission factors from AP-42, trade or technical association data or DEQ should typically be used.
  • If emission factors are available from AP-42, trade or technical association data or DEQ, the source should propose whichever they believe is most representative of their process. If a range of emission factors is provided, use the average of the range to estimate air toxics emissions.
  • When performing material balances using a Safety Data Sheet (SDS), if the SDS specifies a range of air toxics weight percentages, sources must choose the highest value in the range.

This request requires facilities to either estimate their own air toxic emissions or provide information for the agencies to estimate emissions from material balance activities. This information can be retrieved from documents kept onsite such as Safety Data Sheets and Certified Product Data Sheets, also known as Environmental Data Sheets. This documentation provides product information for paints, thinners, solvents and other hazardous materials used at a facility. Safety Data Sheets provide detailed information on chemical composition, health effects, safety procedures, and other characteristics of a variety of products and materials. Suppliers are required to provide Safety Data Sheets for every material upon request and some suppliers make these sheets available on the internet. Each facility is required to keep a current Safety Data Sheet onsite for all the hazardous chemicals used to meet Occupational Safety and Health Administration (OSHA) and other state and federal regulations.

Certified Product Data Sheets (or Environmental Data Sheets) also provide information about chemicals and may provide more concise information than Safety Data Sheets for calculating air toxic emissions.

Finally, some suppliers may provide a Volatile Organic Compounds/Hazardous Air Pollutants report for products purchased by the facility upon request. The report provides purchasing information such as the number of gallons purchased for a given time period and air toxic emissions for the product. The report would save some time for the facility to estimate air toxic emissions but may not contain the complete list of approximately 630 air toxics contaminants.

The reporting forms provide a worksheet for the necessary information to estimate air toxic emissions from material balance activities. All paints, coatings, or solvents should be listed including material usage rates, product density, name and percent weight of air toxic contaminants, any controls used on the process including control and destruction efficiencies, and waste shipped for all facilities. In addition, air toxic emission estimates should be included for facilities issued Title V and Standard and Simple permits. The reporting form should capture a facility's actual and maximum projected emissions information. 

Attention:  There is an issue with the red highlighted example material calculation of the “Material Balance” tab of the reporting form.  This issue only pertains to Simple or Standard ACDP or Title V facilities that report waste shipped offsite. Please refer to question #66 of the Frequently Asked Questions for further explanation. 

Where to look:

For facilities required to estimate their own emissions some resources and research tips are provided below to help look for manufacturer’s emissions data and air toxic emission factors and estimation methodologies. USEPA provides a wealth of information to assist in estimating air toxic emissions such as guidance for identifying sources of air toxics and emission estimation methodologies, and emission factor databases and estimation tools. In addition, state and local agencies in California and Washington are also potential resources for air toxic emission factors and estimation methodologies for similar industries found in Oregon.

Facilities are also encouraged to search the internet for other potential resources and recommends looking at local and state agencies that have Air Toxic Programs. There are several states throughout the nation that have instituted air toxic programs that can be useful resources such as Louisville Kentucky, Michigan, New Jersey, New York, and Rhode Island are just a few. Facilities may also want to check whether local or national trade and technical associations have developed emission factors or estimation methodologies for air toxics as well.

What to look for:

If a facility does not use site-specific source test data, emission factors or emission estimation methodologies then they will need to turn to other resources. First place to look is at the equipment itself such as performance guarantees or actual test data. Many equipment manufacturers include specification and datasheets on the internet. Since the types of equipment and vendors list is too numerous to include on this website the agencies recommend contacting manufacturers directly or by the internet. Additional suggestions are to look for vendors that sell similar equipment or source test data from similar equipment used by a facility that reports air toxics to another state such as California or Washington.

If no emissions information from equipment manufacturers or actual test data from similar equipment is available, emission factors or estimation methodologies from state and federal agencies, or trade and technical associations should be used. Most databases and reference material on the internet are organized by industry type or source category and includes emission factors or calculation methods and process information. This helps facilities search for emission factors and methodologies specific to their industry type. While some resources are arranged through a combination of industry types and emission units and activities. This allows facilities to search either by industry type or just by similar equipment. Many databases are searched by:

  • Source Classification Code (SCC)
  • Industry type
  • Emission unit or activity type which sometimes includes control equipment
  • Pollutant

Facilities should check their permit for SCC’s assigned to a particular emission unit or activity to use in queries. If no SCC is available facilities can look here for SCCs to use in search criteria for any of the databases provided in the links below. The rest of the search criteria for queries should be self evident such as a facility that is an asphalt plant can search by type of industry (asphalt batch or drum mix plants) and by specific equipment (rotary aggregate dryer) or a particular pollutant (Benzene).

Facilities should use emission factors and estimation methodologies that are most representative of their industrial equipment and processes. If a range of emission factors is provided, use the average of the range to estimate air toxics emissions.

A final option is to find other states with similar air permitting programs that have made current permits and technical support documents or permit review reports available on the internet. Southwest Clean Air Agency in Washington has such a website that facilities can query for permitted facilities based on industry type or by business name. A facility can check these types of permits specifically the technical support documents for similar emissions information such as source test data and emission factors. This type of search may be more useful for emission factors or calculation methodologies for pollutants not readily available through other resources such as California’s air toxics emission factors database or USEPA. Facilities can access the permit detail information at Southwest Clean Air Agency: Permit Detail Search (Washington) below.

The following are links to potential resources for estimating air toxic emissions:

USEPA Resources:

California Environmental Protection Agency Air Resources Board:

Other Resources:

The agencies are requesting emissions information on a more comprehensive list of approximately 630 air toxic contaminants than the federal list. Facilities can access an excel version of the list here or in each reporting form provided. Please download the Excel file to search the list.