Certain Monoazo pigments of the Aromatic Azo and Benzidine-based substance grouping

What are they?

  • Thirty-three substances are included in this subgroup screening assessment.
  • Certain Monoazo Pigments are industrial chemicals. They are not expected to occur naturally in the environment.

How are they used?

  • In general, Monoazo Pigments are used as colouring agents in many sectors and products including, cosmetics, paints and coatings, textile and leather, food packaging, colouring agents in drugs and natural health products, formulants in pest control products, military applications, and tattoo inks.
  • Based on the most recent data, some of these Monoazo Pigments are manufactured and/or imported into Canada.

Why did the Government of Canada assess them?

  • Certain Monoazo Pigments were identified as priorities for assessment based on categorization criteria of the Domestic Substances List (DSL).
  • Certain Monoazo Pigments were considered in either the Chemicals Management Plan (CMP) Substance Groupings Initiative and/or the Challenge to Industry. These substances were included for the screening assessment of potential risks to the environment and to human health.
  • Eleven substances included in this subgroup were previously assessed in the earlier Challenge initiative of the CMP. Results of the Challenge assessment for these eleven substances found that one substance (Pigment Red 3) was harmful to human health.
  • Except for the previous Challenge conclusion on human health for Pigment Red 3, which has not been updated, these 11 substances are included in the current assessment to consider significant new information that has been identified.

How are Canadians exposed to them?

  • Exposure of the general population of Canada to Certain Monoazo Pigments via environmental media is not expected.
  • Canadians may be exposed to these pigments during the use of certain products, such as cosmetics (for example, lipstick, face mask, skin moisturizer), arts and crafts materials (for example, finger paint, face paint), textiles, and certain natural health products.

How are they released into the environment?

  • Monoazo Pigments may be released to the environment as a result of industrial processes and during the use and disposal of products containing some of these substances.
  • Monoazo Pigments may be released to the environment from pigment manufacturing, paint/coating formulation, and de-inking processes.

What are the results of the assessment?

  • The Government of Canada has conducted a science-based evaluation of Certain Monoazo Pigments, called a screening assessment.
  • Screening assessments address the potential for harm to the general population of Canada and the environment. Results of the final screening assessment indicate that while Certain Monoazo Pigments are not expected to remain in the environment for a long time, they are expected to accumulate in organisms.
  • Furthermore, the quantity of these substances that may be released to the environment, are below the level expected to cause harm to organisms.
  • The Government of Canada has therefore concluded that none of the Monoazo Pigments assessed is entering the environment at levels that constitute a danger to the environment.
  • The Government of Canada has also concluded that the Monoazo Pigments assessed are not harmful to human health at current levels of exposure.
  • The previous Challenge conclusion that Pigment Red 3 is harmful to human health has not been updated, and therefore remains the same.
  • In addition, the draft screening assessment indicated a potential concern for use of Pigment Red 4 in lipstick and oral natural health products.
  • After further analysis of the exposure from these uses, including updated information indicating lower concentrations of Pigment Red 4 in lipsticks and a refinement of the natural health product risk estimates, the final assessment concludes that Pigment Red 4 is no longer considered harmful to human health at current levels of exposure.  
  • However, given that some of these substances have health effects of concern, there may be concerns if exposures were to increase in Canada.
  • Hazards related to chemicals used in the workplace should be classified accordingly under the Workplace Hazardous Materials Information System (WHMIS).

What is the Government of Canada doing?

  • The Government of Canada published the Final Screening Assessment for Certain Monoazo Pigments on May 28, 2016.
  • Pigment Red 3, which was previously concluded to be harmful to human health and has not been updated in this assessment, has been added to Health Canada's Cosmetic Ingredient Hotlist. The Hotlist is used to keep the cosmetic industry aware of substances that are restricted or prohibited in cosmetics. Under Canadian legislation, cosmetics that contain substances that are harmful to the user cannot be sold.
  • Given the health concerns for some of these substances, the Government will investigate options on how best to monitor changes in the use profile of these substances. Stakeholders will have the opportunity to provide feedback on a consultation document, describing potential options for information gathering or preventative actions, to be published once assessment for all of the Aromatic Azo and Benzidine-based Substance Grouping are completed.
  • The Significant New Activity (SNAc) provisions were applied to Pigment Yellow 60, Pigment Red 251, NANPAP and NAPNPA, following their initial assessment, requiring that any proposed new manufacture, import or use be subject to further assessment to determine if any new activity required further risk management consideration. However, as a result of this new assessment, it is proposed to remove the SNAc provisions on these substances.

What can Canadians do?

  • The health risks associated with a chemical depend on the hazard (its potential to cause health effects) and the dose (the amount of chemical to which you are exposed). The Monoazo Pigments assessed are not presently a concern for the environment or human health at current levels of exposure.
  • Canadians who may be exposed to these Certain Monoazo Pigments in the workplace should consult with their employer and occupational health and safety (OHS) representative about safe handling practices, applicable laws and requirements under the OHS legislation and the Workplace Hazardous Materials Information System (WHMIS).
  • As a general precaution, Canadians are reminded when using any product to carefully follow any safety warnings and directions, and to dispose of the products appropriately.
Monoazo Pigments Assessed by the Government of Canada
CAS RN DSL Name Colour Index Name or Common Name
1103-38-4 1-Naphthalenesulfonic acid, 2-[(2-hydroxy-1-naphthalenyl)azo]-, barium salt (2:1) Pigment Red 49:1
(C.I. 15630:1)
2425-85-6 2-Naphthalenol, 1-[(4-methyl-2-nitrophenyl)azo]- Pigment Red 3
(C.I. 12120)
2512-29-0 Butanamide, 2-[(4-methyl-2-nitrophenyl)azo]-3-oxo-N-phenyl- Pigment Yellow 1
(C.I. 11680)
2786-76-7 2-Naphthalenecarboxamide, 4-[[4-(aminocarbonyl)phenyl]azo]-N-(2-ethoxyphenyl)-3-hydroxy- Pigment Red 170
(C.I. 12475)
2814-77-9 2-Naphthalenol, 1-[(2-chloro-4-nitrophenyl)azo]- Pigment Red 4
(C.I. 12085)
3468-63-1 2-Naphthalenol, 1-[(2,4-dinitrophenyl)azo]- Pigment Orange 5
(C.I. 12075)
5160-02-1 Benzenesulfonic acid, 5-chloro-2-[(2-hydroxy-1-naphthalenyl)azo]-4-methyl-, barium salt (2:1) Pigment Red 53:1
(C.I. 15585:1)
6372-81-2 Benzoic acid, 2-[(2-hydroxy-1-naphthalenyl)azo]-, barium salt (2:1) Pigment Red 50:1
(C.I. 15500:1)
6407-74-5 3H-Pyrazol-3-one, 4-[(2-chlorophenyl)azo]-2,4-dihydro-5-methyl-2-phenyl- Pigment Yellow 60
(C.I. 12705)
6410-09-9 2-Naphthalenol, 1-[(2-nitrophenyl)azo]- Pigment Orange 2
(C.I. 12060)
6410-13-5 2-Naphthalenol, 1-[(4-chloro-2-nitrophenyl)azo]- Pigment Red 6
(C.I. 12090)
6410-41-9 2-Naphthalenecarboxamide, N-(5-chloro-2,4-dimethoxyphenyl)-4-[[5-[(diethylamino)sulfonyl]-2-methoxyphenyl]azo]-3-hydroxy- Pigment Red 5
(C.I. 12490)
6417-83-0 2-Naphthalenecarboxylic acid, 3-hydroxy-4-[(1-sulfo-2-naphthalenyl)azo]-, calcium salt (1:1) Pigment Red 63:1
(C.I. 15880:1)
6486-23-3 Butanamide, 2-[(4-chloro-2-nitrophenyl)azo]-N-(2-chlorophenyl)-3-oxo- Pigment Yellow 3
(C.I. 11710)
6535-46-2 2-Naphthalenecarboxamide, 3-hydroxy-N-(2-methylphenyl)-4-[(2,4,5-trichlorophenyl)azo]- Pigment Red 112
(C.I. 12370)
7023-61-2 2-Naphthalenecarboxylic acid, 4-[(5-chloro-4-methyl-2-sulfophenyl)azo]-3-hydroxy-, calcium salt (1:1) Pigment Red 48:2
(C.I. 15865:2)
12236-62-3 Butanamide, 2-[(4-chloro-2-nitrophenyl)azo]-N-(2,3-dihydro-2-oxo-1H-benzimidazol-5-yl)-3-oxo- Pigment Orange 36
(C.I. 11780)
12236-64-5 2-Naphthalenecarboxamide, N-[4-(acetylamino)phenyl]-4-[[5-(aminocarbonyl)-2-chlorophenyl]azo]-3-hydroxy- Pigment Orange 38
(C.I. 12367)
12238-31-2 Pigment Red 52:2   Pigment Red 52:2
(C.I. 15860:2)
13515-40-7 Butanamide, 2-[(4-chloro-2-nitrophenyl)azo]-N-(2-methoxyphenyl)-3-oxo- Pigment Yellow 73
(C.I. 11738)
13824-00-5 2-Naphthalenecarboxamide, 3-hydroxy-N-(4-methoxyphenyl)-4-[(4-methylphenyl)azo]- NAPMPA
16403-84-2 2-Naphthalenecarboxamide, 4-[[5-(aminocarbonyl)-2-methylphenyl]azo]-3-hydroxy-N-phenyl- Pigment Red 268
(C.I. 12316)
17852-99-2 2-Naphthalenecarboxylic acid, 4-[(4-chloro-5-methyl-2-sulfophenyl)azo]-3-hydroxy-, calcium salt (1:1) Pigment Red 52:1
(C.I. 15860:1)
17947-32-9 2-Naphthalenecarboxamide, 3-hydroxy-N-(4-methoxyphenyl)-4-(phenylazo)- NAPPA
36968-27-1 2-Naphthalenecarboxamide, 4-[[4-(aminocarbonyl)phenyl]azo]-3-hydroxy-N-(2-methoxyphenyl)- Pigment Red 266
(C.I. 12474)
43035-18-3 Benzenesulfonic acid, 4-[[3-[[2-hydroxy-3-[[(4-methoxyphenyl)amino]carbonyl]-1-naphthalenyl]azo]-4-methylbenzoyl]amino]-, calcium salt (2:1) Pigment Red 247
(C.I. 15915)
49744-28-7 2-Naphthalenol, 1-[(4-methoxy-2-nitrophenyl)azo]- NONPA
59487-23-9 2-Naphthalenecarboxamide, 4-[[5-[[[4-(aminocarbonyl)phenyl]amino]carbonyl]-2-methoxyphenyl]azo]-N-(5-chloro-2,4-dimethoxyphenyl)-3-hydroxy- Pigment Red 187
(C.I. 12486)
71832-83-2 2-Naphthalenecarboxylic acid, 4-[(5-chloro-4-methyl-2-sulfophenyl)azo]-3-hydroxy-, magnesium salt (1:1) Pigment Red 48:5
(C.I. 15865:5)
74336-60-0 9,10-Anthracenedione, 1-[(5,7-dichloro-1,9-dihydro-2-methyl-9-oxopyrazolo[5,1-b]quinazolin-3-yl)azo]- Pigment Red 251
(C.I. 12925)
83249-60-9 1-Naphthalenesulfonic acid, 2-[(2-hydroxy-6-sulfo-1-naphthalenyl)azo]-, calcium salt (1:1) NSNAC
85005-63-6 2-Naphthalenecarboxamide, 4-[(2,4-dinitrophenyl)azo]-3-hydroxy-N-phenyl- NANPAP
94199-57-2 2-Naphthalenecarboxamide, N-(2-ethoxyphenyl)-3-hydroxy-4-[(2-nitrophenyl)azo]- NAPNPA

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