Chemicals of High Concern

Maine law requires the Department of Environmental Protection to publish a list of no more than 70 chemicals of high concern. Development of Maine’s list of Chemicals of High Concern (CHC) is to be cooperatively determined by the Maine Department of Health and Human Services, Maine Center for Disease Control and Prevention (“Maine CDC”), and the Maine Department of Environmental Protection (“Department”). (38 M.R.S.A. § 1693-A(1)). A chemical currently listed on Maine’s chemicals of concern list may be included on the CHC list if there is a determination of strong, credible scientific evidence that the chemical is a reproductive or developmental toxicant, endocrine disruptor or human carcinogen, AND there is strong, credible scientific evidence that the chemical meets one or more of the following criteria:

  • The chemical has been found through biomonitoring studies to be present in human blood, human breast milk, human urine or other bodily tissues or fluids;
  • The chemical has been found through sampling and analysis to be present in household dust, indoor air or drinking water or elsewhere in the home environment; or
  • The chemical has been added to or is present in a consumer product used or present in the home.

As directed by Maine law, the Commissioner has undertaken a review of the Chemicals of High Concern list, published July 2012, pursuant to 38 M.R.S.A. § 1693-A(1). This review included removal of chemicals that have been designated as priority, and those that no longer meet the criteria established in statute for inclusion on the Chemicals of High Concern list, as set forth in Maine law 38 § 1693-A(2).

The process used to determine Maine’s CHC list is summarized within supporting documentation provided here.

Maine has designated 36 compounds as Chemicals of High Concern

Chemicals of High Concern
CAS Chemical
71-43-2 Benzene
75-01-4 Vinyl chloride
79-94-7 Tetrabromobisphenol A
84-61-7 Dicyclohexyl phthalate; DCHP
91-59-8 2-Naphthylamine
92-69-3 4-Hydroxybiphenyl
92-87-5* Benzidine and its salts
94-13-3 Propyl paraben
94-26-8 Butyl paraben
95-53-4 2-Aminotoluene
99-76-3 Methyl paraben
99-96-7 p-Hydroxybenzoic acid
100-42-5 Styrene
101-14-4 4,4 -Methylenebis(2-Chloroaniline)
106-89-8 Epichlorohydrin
106-93-4 1,2-Dibromoethane
106-99-0 1,3-Butadiene
108-88-3 Toluene
118-74-1 Hexachlorobenzene
120-47-8 Ethyl paraben
131-55-5  2,2',4,4'-tetrahydroxybenzophenone, BP-2
131-56-6 2,4-Dihydroxybenzophenone
131-70-4 Mono-n-butylphthalate
140-66-9 1,1,3,3-Tetramethyl-4-butylphenol
556-67-2 Octamethylcyclotetrasiloxane
608-93-5 Benzene, pentachloro-
1163-19-5 2,2',3,3',4,4',5,5',6,6'-Decabromodiphenyl ether; BDE-209
1634-04-4 Methyl tert-butyl ether; MTBE
1763-23-1* Perfluorooctane sulfonic acid (PFOS) and its salts
1806-26-4 Phenol, 4-octyl-
5466-77-3 2-ethyl-hexyl-4-methoxycinnamate
14808-60-7 Silica, crystalline (in the form of quartz or cristobalite dust)
25013-16-5 Butylated hydroxyanisole
25637-99-4 Hexabromocyclododecane
27193-28-8 (1,1,3,3-tetramethylbutyl)-phenol
N/A Nickel compounds

* CAS numbers are specific for the parent chemical, but the CHC listing includes both the parent chemical and parent chemical-related salt compounds.

For additional information contact: Kerri Malinowski or (207) 215-1894