Pollutant categories for air toxics

There are 194 individual air toxic chemicals and 303 chemicals within 29 groups included in the air toxics emission inventory. This list includes the 188 hazardous air pollutants (HAPs) identified by the EPA, pollutants in the Great Lakes regional air toxics emission inventory project, and pollutants of concern in Minnesota’s outdoor air: File List of individual pollutants and commonly reported individual pollutants in groups (aq-ei4-32)

The presentation of emissions data for specific groups of compounds is described below. Efforts are made to avoid the same emission being counted twice. On the MPCA’s website, emissions are reported for various chemical groups while the detailed chemical-specific emissions are available and can be obtained by contacting the MPCA.

Recommendations for reporting data for specific groups of compounds are summarized below in a hierarchy of the most preferred method to the least preferred method. For pollutant groups, only one reporting strategy per group per process should be used. Simultaneous use of more than one reporting strategy (e.g., reporting both individual chromium compounds and total chromium for the same source) will result in double counting.

Metal and cyanide groups

  1. Report emissions of all individual metal and cyanide compounds (e.g., report emissions of arsenic trioxide). Reporting “arsenic compound” as a whole will not be accepted. All individual compounds should be reported as the mass of the total compounds, not just the metal within the compound.
  2. Report just emissions of metal or cyanide within the compound (e.g., if you have emissions of 1 lb of arsenic trioxide, you can report 0.7574 lb of arsenic emissions within the arsenic trioxide0.
    • Chromium - Since there is widely varying toxicity, you need to separate chromium compounds into trivalent (CHROMIUM III, CAS No.16065-83-1) and hexavalent chromium (CHROMIUM VI, CAS No. 18540-29-9) if possible. You may report emissions for chromium if you cannot separate emissions. If the emissions are reported for chromium, the emissions will be allocated to CHROMIUM III and CHROMIUM VI based on generic information when the data are used.
    • Do not include metals or cyanide already reported using the more preferred method in number 1. The e-service will give an error message if both are reported.

Dioxins/furans

Report mass emissions of the following 17 individual congeners of chlorinated dibenzodioxins (CDDs) and chlorinated dibenzofurans (CDFs).

Pollutant code

Short description

CAS No.

HPCDD1234678

1,2,3,4,6,7,8-Heptachlorodibenzodioxin

35822-46-9

HPCDF1234678

1,2,3,4,6,7,8-Heptachlorodibenzofuran

67562-39-4

HPCDF1234789

1,2,3,4,7,8,9-Heptachlorodibenzofuran

55673-89-7

HXCDD,123478

1,2,3,4,7,8-Hexachlorodibenzodioxin

39227-28-6

HXCDD,123678

1,2,3,6,7,8-Hexachlorodibenzodioxin

57653-85-7

HXCDD,123789

1,2,3,7,8,9-Hexachlorodibenzodioxin

19408-74-3

HXCDF,123478

1,2,3,4,7,8-Hexachlorodibenzofuran

70648-26-9

HXCDF,123678

1,2,3,6,7,8-Hexachlorodibenzofuran

57117-44-9

HXCDF,123789

1,2,3,7,8,9-Hexachlorodibenzofuran

72918-21-9

HXCDF,234678

2,3,4,6,7,8-Hexachlorodibenzofuran

60851-34-5

OCDD,TOT

Octachlorodibenzodioxins, All Isomers

3268-87-9

OCDF,TOT

Octachlordibenzofurans, All Isomers

39001-02-0

PECDD,12378

1,2,3,7,8-Pentachlorodibenzodioxin

40321-76-4

PECDF,12378

1,2,3,7,8-Pentachlordibenzofuran

57117-41-6

PECDF,23478

2,3,4,7,8-Pentachlordibenzofuran

57117-31-4

TCDD,2378

2,3,7,8-Tetrachlorodibenzo-P-Dioxin

1746-01-6

TCDF,2378

2,3,7,8-Tetrachlorodibenzofuran

51207-31-9

Glycol ethers

  1. Report emissions for individual glycol ethers. All individual glycol ethers are shown on the air toxics pollutant list. EPA, uses the Toxics Release Inventory (TRI) List of Toxic Chemicals within the Glycol Ethers Category to determine if a chemical falls into a glycol ether category. If the chemical is not listed in Table 1 of the above guidance please use the structural definition provided by EPA to determine if the chemical is a glycol ether. The definition is:
    R-(OCH2CH2)n-R'  where
    n = 1, 2 or 3
    R = alkyl C7 or less; or R = phenyl or alkyl substituted phenyl;
    R' = H or alkyl C7 or less; or OR' consisting of carboxylic acid ester, sulfate, phosphate, nitrate, or sulfonate.
  2. If you cannot report individual glycol ether emissions, report total emissions of glycol ethers as a group under pollutant code “GLYCOL ETHERS.” You should not report emissions of one pollutant under both the individual pollutant name and “GLYCOL ETHERS”. The e-service will give an error message if both are reported.

Xylenes and Cresols

  1. Report emissions for individual xylene and cresol isomers. If you report emissions for individual isomers do not report any emissions for total xylenes or total cresols to avoid double counting.
  2. If you cannot report individual emissions of xylenes or cresols, report total emissions of xylenes or cresols as a group under “XYLENES ISO” (CAS No. 1330-20-7) or “CRESOLS MX IS” (CAS No. 1319-77-3).

Polycyclic organic matter (POM)

Report emissions of as many individual POM compounds as possible. All POMs are shown on the AT pollutant list.

2020 Emissions Inventory updates

In June 2020, EPA added bromopropane (1-BP) CAS No. (106-94-5), also known as n-propyl bromide (nPB), to the list of Hazardous Air Pollutants (HAPs).

Trichloroethylene (TCE)

In May 2020, the Minnesota Legislature passed a ban on TCE use in the state. The ban was signed into law by the governor and is a first of its kind in the nation. Since the ban was enacted, MPCA has added three additional chemicals to our pollutant reporting list as TCE substitutes.

Pollutant code

Short description

CAS No.

DCE,12TRANS

trans-1,2-DCE

156-60-5

DCE,12MIX

1,2-DCE Compounds/Mixture

540-59-0

BUTOXYPROPA,N

3-butoxypropan-2-ol

5131-66-8

Polyfluoroalkyl substances (PFAS)

MPCA added 5 PFAS pollutants to the list of reportable pollutants. These pollutants are of particular interest in Minnesota because they have a drinking water health standard.

Pollutant code

Short description

CAS No.

PFOS

Perfluorooctanesulfonic acid / perfluorooctane sulfonate

1763-23-1

PFOA

Perfluorooctanoic acid 

335-67-1

PFBS

Perfluorobutanesulfonic acid 

375-73-5

PFHxS

Perfluorohexanesulfonic acid

355-46-4

PFBA

Perfluorobutanoate / Perfluorobutanoic Acid 

375-22-4

Aluminum

1. For the 2020 emission inventory, MPCA added aluminum oxide (1344-28-1) and aluminum fluoride (7784-18-1) to the list of reportable compounds. Report emissions for individual compounds. If you report emissions for individual compounds do not report any emissions for total aluminum to avoid double counting.

2. If you cannot report individual emissions of aluminum compounds, report total emissions of aluminum under ALUMINUM (CAS. No. 7429-90-5).

Vanadium

1. For the 2020 emission inventory, MPCA added ferrovanadium (12604-58-9) on the list of reportable compounds. Report emissions for the individual compound. If you report emissions for ferrovanadium do not report any emissions for total vanadium to avoid double counting.

2. If you cannot report individual emissions of ferrovanadium, report total emissions of vanadium under VANADIUM (CAS. No. 7440-62-2).