The appropriate PM emission factor to use will vary depending on what information is available for your particular process. Our current guidance is as follows:
- If no PM-10 emission factor is available, use the total particulate emission factors to calculate PM-10 emissions.
- If no information regarding PM-2.5 is available, you are not required to calculate a separate PM2.5 emissions value.
- If no information regarding condensable PM (PM-CON) is available, you are not required to calculate a PM-CON emissions value.
The following are examples of possible PM emissions calculation scenarios. If you need additional assistance with PM emission factors, please contact us.
Example 1
For an uncontrolled industrial boiler firing distillate oil, Table 1.3-6 in AP-42 lists the following PM-filterable emission factors:
- PM-10: 1 pound per 1,000 gallons (gal) fuel
- PM2.5: 0.25 pounds per 1,000 gal fuel
For an uncontrolled industrial boiler firing distillate oil, Table 1.3-2 in AP-42 lists the following PM-CON emission factor: 1.3 pounds per 1000 gal fuel.
In this case, the proper emission factors are:
- PM10-PRI: 2.3 pounds per 1,000 gal fuel
- PM10-FIL: 1 pounds per 1,000 gal fuel
- PM2.5-PRI: 1.55 pounds per 1,000 gal fuel
- PM2.5-FIL: 0.25 pounds per 1,000 gal fuel
- PM-CON: 1.3 pounds per 1000 gal fuel
Example 2
For an uncontrolled natural gas fired boiler, Table 1.4-2 in AP-42 lists the following PM emission factors:
- PM-CON: 5.7 pounds per 106 standard cubic feet (scf) fuel
- PM-filterable: pounds per 106 scf fuel
A footnote states that all PM is assumed to be less than 1 micrometer in diameter, and, therefore, these factors can be used to calculate PM-10 or PM-2.5.
In this case, the proper emission factors are:
- PM10-PRI: 7.6 pounds per 106 scf fuel
- PM10-FIL: 1.9 pounds per 106 scf fuel
- PM2.5-PRI: 7.6 pounds per 106 scf fuel
- PM2.5-FIL: 1.9 pounds per 106 scf fuel
- PM-CON: 5.7 pounds per 106 scf fuel
Example 3
For an uncontrolled preheated kiln in a cement manufacturing process, Table 11.6-2 in AP-42 lists a filterable total suspended particles (TSP) emission factor of 250 pounds per ton clinker produced. There is no information on PM-10 or PM-2.5 emissions or condensable particulate matter emissions. In this case, the filterable TSP emission factor would be used to calculate PM-10 and no PM-2.5 emissions would be calculated.
In this case, the proper emission factors are:
- PM-10-PRI: 250 pounds per ton of clinker
- PM-10-FIL: 250 pounds per ton of clinker