Dyes of the Aromatic Azo and Benzidine-based Substance Grouping

The aromatic azo and benzidine-based substances are among those identified as priorities. Read more about the Aromatic Azo and Benzidine-based Substance Grouping.

Release guidelines

In September 2020, Release Guidelines for Disperse Yellow 3 and 25 other Azo Disperse Dyes in the Textile Sector were published in the Canada Gazette, Part I: Vol 154, No. 36 – September 5, 2020. These guidelines address 26 azo disperse dyes with molar weights below 360 grams per mole (g/mol), including Disperse Yellow 3 (DY3). Exposures of concern for the 26 azo disperse dyes are their release to water resulting from textile dye formulation and textile dyeing activities. The guidelines recommend limits for the release of the 26 azo dyes into the aquatic environment from textile dye formulation and textile dyeing activities. These guidelines cannot be used as a substitute for, or be in conflict with, existing regulatory requirements.

The overall goal of these release guidelines is to limit releases of DY3 and the 25 other azo disperse dyes with molar weights below 360 g/mol to levels below the Predicted No Effect Concentration (PNEC) of 2.3 micrograms per litre (µg/L) at the final discharge point of textile facilities.

In February 2019, the Proposed Release Guidelines for Disperse Yellow 3 and 25 other Azo Disperse Dyes in the Textile Sector were published in the Canada Gazette, Part I: Vol. 153, No. 8 – February 23, 2019 for a 60-day public comment period. Comments received during the public comment period were taken into consideration in the development of the final release guidelines.

Consultation document

Some aromatic azo and benzidine-based substances, although concluded not to pose a risk to the environment or to human health at current levels of exposure, may be a concern if environmental exposures or exposures of the general population of Canada to these substances were to increase.

Options on how best to monitor changes in uses of substances identified to have environmental and/or human health effects of concern are being investigated, and this was communicated to stakeholders when the draft screening assessments were published. Health Canada and Environment and Climate Change Canada have published a Consultation Document on the Options for Addressing Aromatic Azo and Benzidine-based Substances with Effects of Concern, which describes potential options for information gathering or preventive actions on substances identified to have environmental or health effects of concern.

Stakeholders had the opportunity to provide feedback during the consultation period, which closed May 10, 2017. These comments and the Government's response to comments relating to the consultation document are provided in the Summary of the comments submitted on the consultation document for the options to address certain aromatic azo and benzidine-based substances with effects of concern and the risk management approach for Disperse Yellow 3.

Adding substances to Schedule 1

Disperse Yellow 3 (CAS RN 2832-40-8) has been added to Schedule 1.

Summary of publications

Final screening assessments for dyes of the Aromatic Azo and Benzidine-based Substance Grouping
Subgroup Chemical substances Final order and RIAS Public comments on the draft screening assessment Final screening assessment Proposed risk management approach Public comments on the proposed risk management approach
Certain Azo Acid Dyes See List of Certain Azo Acid Dyes n/a HTML HTML n/a n/a
Certain Azo Basic Dyes See List of Certain Azo Basic Dyes n/a HTML HTML n/a n/a
Certain Azo Direct Dyes and Certain Azo Reactive Dyes See List of Certain Direct Dyes and List of Certain Reactive Dyes n/a HTML HTML n/a n/a
Certain Azo Disperse Dyes See List of Certain Azo Disperse Dyes CAS RN 2832-40-8:
HTML
HTML HTML CAS RN 2832-40-8:
HTML
All others:
n/a
CAS RN 2832-40-8 and 25 other azo disperse dyes
HTML
All others: n/a
Certain Azo Metal Complexes and Other Azo Substances See List of Certain Azo Metal Complexes and Other Azo Substances n/a n/a HTML n/a n/a
Certain Azo Solvent Dyes See List of Certain Azo Solvent Dyes

CAS RN 2832-40-8: HTML

All others: n/a

n/a HTML CAS RN 85-86-9: Refer to the risk management action milestones for Solvent Red 23 n/a
Certain Benzidine-based Dyes and Related Substances See List of Certain Benzidine-based Dyes and Related Substances n/a HTML HTML n/a n/a
Timelines
Date Subgroup affected Activity
September 5, 2020 Certain Azo Disperse Dyes Publication in the Canada Gazette, Part I, of Release Guidelines for Disperse Yellow 3 and 25 other Azo Disperse Dyes in the Textile Sector.
April 24, 2019 Certain Azo Disperse Dyes Deadline for submission of public comments on the Proposed Release Guidelines for Disperse Yellow 3 and 25 other Azo Disperse Dyes in the Textile Sector.
February 23, 2019 Certain Azo Disperse Dyes Publication in the Canada Gazette, Part I, of the Proposed Release Guidelines for Disperse Yellow 3 and 25 other azo disperse dyes in the textile sector.
July 11, 2018 Certain Azo Disperse Dyes Publication in Canada Gazette, Part II, of the final order adding Disperse Yellow 3 (CAS RN 2832-40-8) to Schedule 1 under the Canadian Environmental Protection Act, 1999 (CEPA 1999).
July 12, 2017 Certain Azo Disperse Dyes Publication in Canada Gazette, Part II, of an order amending the Domestic Substances List (DSL) to rescind requirements under the Significant New Activity (SNAc) provisions for 33 substances.
May 31, 2017 Certain Azo Disperse Dyes Deadline for submission of public comments on the proposed order adding Disperse Yellow 3 (CAS RN 2832-40-8) to Schedule 1.
May 10, 2017 Certain Azo Disperse Dyes Deadline for submission of public comments on proposed Risk Management Approach for Disperse Yellow 3 (CAS RN 2832-40-8).
April 1, 2017 Certain Azo Disperse Dyes Publication in Canada Gazette, Part I, of proposed order adding Disperse Yellow 3 (CAS RN 2832-40-8) to Schedule 1 under CEPA 1999, and start of 60-day public comment period.
March 11, 2017 Certain Azo Disperse Dyes Publication in Canada Gazette, Part I, of final assessment decisions under subsection 77(6) of CEPA 1999, release of the Risk Management Approach for Disperse Yellow 3 (CAS RN 2832-40-8) and start of 60-day public comment period on the proposed risk management approach and the proposal to rescind the requirements under the SNAc provisions for 33 substances.
October 19, 2016 Certain Azo Basic Dyes, Certain Azo Solvent Dyes Publication in Canada Gazette, Part II, of order amending the DSL to rescind the requirements under the SNAc provisions on CAS RNs 59709-10-3, 2653-64-7, 73528-78-6 and 85392-21-8).
June 18, 2016 Certain Azo Acid Dyes Publication in Canada Gazette, Part I, of final assessment decision under subsection 77(6) of CEPA 1999.
May 28, 2016 Certain Azo Basic Dyes Publication in Canada Gazette, Part I, of final assessment decision under subsection 77(6) of CEPA 1999 and proposal to rescind the requirements under the SNAc provisions for one substance, CAS RN 59709-10-3.
May 28, 2016 Certain Azo Solvent Dyes Publication in Canada Gazette, Part I, of final assessment decision under subsection 77(6) of CEPA 1999.
April 4, 2015 Certain Azo Direct Dyes, Certain Azo Reactive Dyes Publication in Canada Gazette, Part I, of final assessment decision under subsection 77(6) of CEPA 1999.
April 4, 2015 Certain Azo Metal Complexes and Other Azo Substances Publication in Canada Gazette, Part I, of final assessment decision under subsection 77(6) of CEPA 1999.
March 11, 2015 Certain Benzidine-based Dyes and Related Substances Publication in Canada Gazette, Part II, of order amending the DSL to rescind the requirements under the SNAc provisions on TDBD (CAS RN 1871-22-3).
December 24, 2014 Certain Azo Acid Dyes Deadline for submission of public comments on draft screening assessment.
November 29, 2014 Certain Benzidine-based Dyes and Related Substances Publication in Canada Gazette, Part I, of final assessment decision under subsection 77(6) of CEPA 1999 and proposal to rescind the SNAc provisions for 1 substance, TDBD (CAS RN 1871-22-3).
October 25, 2014 Certain Azo Acid Dyes Publication in Canada Gazette, Part I, of proposed assessment decision under subsection 77(1) of CEPA 1999, and start of 60-day public comment period on the draft screening assessment.
September 24, 2014 Certain Azo Basic Dyes Deadline for submission of public comments on draft screening assessments.
July 26, 2014 Certain Azo Basic Dyes Publication in Canada Gazette, Part I, of proposed assessment decision under subsection 77(1) of CEPA 1999, and start of 60-day public comment period on the draft screening assessment.
July 16, 2014 Certain Azo Metal Complexes and Other Azo Substances Deadline for submission of public comments on draft screening assessments.
May 28, 2014 Certain Azo Direct Dyes, Certain Azo Reactive Dyes Deadline for submission of public comments on draft screening assessments.
May 17, 2014 Certain Azo Metal Complexes and Other Azo Substances Publication in Canada Gazette, Part I, of proposed assessment decision under subsection 77(1) of CEPA 1999, and start of 60-day public comment period on the draft screening assessment.
March 29, 2014 Certain Azo Direct Dyes, Certain Azo Reactive Dyes Publication in Canada Gazette, Part I, of proposed assessment decision under subsection 77(1) of CEPA 1999, and start of 60-day public comment period on the draft screening assessment.
January 1, 2014 Certain Azo Disperse Dyes, Certain Azo Solvent Dyes Deadline for submission of public comments on the draft screening assessments and the Risk Management Scope for Azo Disperse Dyes (including CAS RN 2832-40-8).
November 2, 2013 Certain Azo Disperse Dyes, Certain Azo Solvent Dyes Publication in Canada Gazette, Part I, of proposed assessment decisions under subsection 77(1) of CEPA 1999 and start of 60-day public comment period on a) the draft screening assessments and b) the proposed Risk Management Scope for Azo Disperse Dyes (including CAS RN 2832-40-8).
August 14, 2013 Certain Benzidine-based Dyes and Related Substances Deadline for submission of public comments on draft screening assessment.
June 15, 2013 Certain Benzidine-based Dyes and Related Substances Publication in Canada Gazette, Part I, of proposed assessment decision under subsection 77(1) of CEPA 1999, and start of 60-day public comment period on the draft screening assessment.
April 16, 2012 Certain Azo Acid Dyes, Certain Azo Basic Dyes, Certain Azo Direct Dyes, Certain Azo Disperse Dyes, Certain Azo Metal Complexes and Other Azo Substances, Certain Azo Reactive Dyes, Certain Azo Solvent Dyes, and Certain Benzidine-based Dyes and Related Substances Deadline for submission of additional information by interested stakeholders, including on the extent and nature of the management/stewardship.
If needed, information gathering tools could be used to inform potential risk management actions.

Final screening assessments and risk management approaches

Certain Azo Acid Dyes

In June 2016, the final screening assessment for 52 substances was released and the related notice was published in the Canada Gazette, Part I: Vol. 150, No. 25 – June 18, 2016.

The final screening assessment concluded that these 52 substances do not meet any of the criteria under section 64 of the CEPA 1999. Therefore, the Minister of the Environment and the Minister of Health have proposed to take no further action on these substances at this time under the Act.

In October 2014, the draft screening assessment was released and the related notice was published in the Canada Gazette, Part I: Vol. 148, No. 43 - October 25, 2014.

Certain Azo Basic Dyes

In May 2016, the final screening assessment for 33 substances was released and the related notice was published in the Canada Gazette, Part I: Vol. 150, No. 22 - May 28, 2016.

The final screening assessment concluded that these 33 substances do not meet any of the criteria under section 64 of CEPA 1999. Therefore, the Minister of the Environment and the Minister of Health have proposed to take no further action on these substances at this time under the Act.

Among the 33 substances in the Azo Basic Dyes subgroup, 1 substance (NDTHPM) was previously assessed under Batch 9 of the Challenge Initiative of the Chemicals Management Plan (CMP) and was found not to pose a risk to the environment or to human health as set out in section 64 of CEPA 1999. This conclusion remains unchanged.

One of the azo basic dyes (CAS RN 59709-10-3) was previously assessed in April 2008 as part of an assessment of 145 Persistent, Bioaccumulative and inherently Toxic (PBiT) substances under CEPA 1999. That assessment identified a potential ecological concern with respect to new uses for CAS RN 59709-10-3 and, therefore, the Government of Canada had applied the SNAc provisions to this substance. The current screening assessment concludes that this substance is no longer of concern to the environment, nor considered as having effects of concern. Consequently, an order was published in the Canada Gazette, Part II in October 2016 rescinding the requirements under the SNAc provisions of CEPA 1999 for this substance.

In July 2014, the draft screening assessment was released and the related notice was published in the Canada Gazette, Part I: Vol. 148, No. 30 – July 26, 2014 for a 60-day public comment period.

Certain Azo Direct Dyes and Certain Azo Reactive Dyes

In April 2015, the final screening assessment for 69 substances was released and the related notice was published in the Canada Gazette, Part I: Vol. 149, No. 14 - April 4, 2015.

The final screening assessment concluded that these 69 substances do not meet any of the criteria under section 64 of CEPA 1999. Therefore, the Minister of the Environment and the Minister of Health have proposed to take no further action on these substances at this time under the Act.

In March 2014, the draft screening assessment was released and the related notice was published in the Canada Gazette, Part I: Vol. 148, No. 13 - March 29, 2014.

Certain Azo Disperse Dyes

In March 2017, the final screening assessment for 74 substances was released and the related notice was published in the Canada Gazette, Part I, Vol. 151, No. 10 - March 11, 2017.

The final screening assessment concluded that 73 of the 74 substances do not meet any of the criteria under section 64 of CEPA 1999. Therefore, the Minister of the Environment and the Minister of Health have proposed to take no further action on these 73 substances at this time under the Act.

The final screening assessment also concluded that the remaining substance, Disperse Yellow 3, is harmful to the environment and meets the criteria set out in paragraph 64(a) of CEPA 1999. A Proposed Risk Management Approach for Disperse Yellow 3 was also released on this date for a 60-day public comment period.

These 74 substances were initially concluded to be harmful to the environment at the draft screening assessment stage. New information received after that publication has led to a change in the ecological conclusion in the final screening assessment.

Thirty-two of the azo disperse dyes were previously assessed in April 2008 as part of an assessment of 145 PBiT substances and 1 of the azo disperse dyes was previously assessed in August 2009 under Batch 5 of the Challenge Initiative of the CMP. Those assessments identified a potential ecological concern with respect to new uses for these substances and, therefore, the Government of Canada applied the SNAc provisions to these 33 substances. The current screening assessment concludes that these 33 substances are no longer of concern to the environment. Consequently, an order was published in the Canada Gazette, Part II in July 2017 rescinding the requirements under the SNAc provisions of CEPA 1999 for these substances.

In November 2013, the draft screening assessment for 73 substances was released and the related notice was published in the Canada Gazette, Part I: Vol. 147, No. 44 - November 2, 2013. A Risk Management Scope for Azo Disperse Dyes was also released on this date for a 60-day public comment period.

Certain Azo Metal Complexes and Other Azo Substances

In April 2015, the final screening assessment for 6 substances was released and the related notice was published in the Canada Gazette, Part I: Vol. 149, No. 14 - April 4, 2015.

The final screening assessment concluded that these 6 substances do not meet any of the criteria under section 64 of CEPA 1999. Therefore, the Minister of the Environment and the Minister of Health proposed to take no further action on these substances at this time under the Act.

In May 2014, the draft screening assessment was released and the related notice was published in the Canada Gazette, Part I: Vol. 148, No. 20 - May 17, 2014 for a 60-day public comment period.

Certain Azo Solvent Dyes

In May 2016, the final screening assessment for 22 substances was released and the related notice was published in the Canada Gazette, Part I: Vol. 150, No. 22 - May 28, 2016.

The final screening assessment concluded that these 22 substances do not meet any of the criteria set out in section 64 of CEPA 1999. Therefore the Minister of the Environment and the Minister of Health have proposed to take no further action on these substances at this time under the Act.

The ecological component of the screening assessment for Solvent Yellow 77, (also known as Disperse Yellow 3) which presented a proposed toxic to the environment conclusion in the draft screening assessment, was included in the final screening assessment of Certain Azo Disperse Dyes that was published in March 2017. The human health conclusion for this substance is also included in the Azo Disperse Dyes assessment.

Two substances included in the solvent dyes subgroup, Solvent Red 3 and Solvent Yellow 18, were previously assessed under the Challenge Initiative of the CMP. Three other substances included in the Solvent Dyes subgroup, Solvent Red 4 (CAS RN 2653-64-7), CAS RN 73528-78-6 and CAS RN 85392-21-8, were previously assessed in April 2008 as part of an assessment of 145 PBiT substances. As a result of the conclusions of these previous screening assessments, the Government applied the SNAc provisions to these five substances. The current screening assessment concludes that these 5 substances are no longer of concern to the environment, nor considered as having health effects of concern. Consequently, an order was published in the Canada Gazette, Part II in October 2016 rescinding the requirements under the SNAc provisions of CEPA 1999 for these 5 substances.

Five substances in this subgroup were previously assessed under the Challenge Initiative of the CMP: Solvent Red 1 (CAS RN 1229-55-6), Solvent Red 3 (CAS RN 6535-42-8), Solvent Orange 7 (CAS RN 3118-97-6) and Solvent Red 23 (CAS RN 85-86-9) were assessed in Batch 6, and Solvent Yellow 18 (CAS RN 6407-78-9) was assessed in Batch 7. It was concluded that Solvent Red 23 poses a risk to human health as set out in paragraph 64(c) of CEPA 1999. The conclusions for these substances previously assessed under the Challenge Initiative remain unchanged.

Significant new information relevant to the assessment of Azo Solvent Dyes, including the 5 substances previously assessed under the Challenge Initiative, informed the ecological assessment of the Azo Solvent Dyes subgroup. Similarly, significant new information relevant to the assessment of Solvent Red 1, Solvent Red 3 and Solvent Yellow 18 informed the human health assessment of the Azo Solvent Dyes subgroup. The screening assessment of Azo Solvent Dyes reflects this updated information.

In November 2013, the draft screening assessment was released and the related notice was published in the Canada Gazette, Part I: Vol. 147, No. 44 - November 2, 2013. A Risk Management Scope for Solvent Yellow 77 (and Azo Disperse Dyes) was also released on this date. 60-day public comment periods were associated with these publications.

Certain Benzidine-based Dyes and Related Substances

In November 2014, the final screening assessment for 42 substances was released and the related notice was published in the Canada Gazette, Part I: Vol. 148, No. 48 - November 29, 2014.

The final screening assessment concluded that these 42 substances do not meet any of the criteria under section 64 of CEPA 1999. Therefore, the Minister of the Environment and the Minister of Health have proposed to take no further action on these substances at this time under the Act.

Five subgroups are included in this screening assessment; Benzidine-based Acid Dyes (9 substances), Benzidine-based Direct Dyes (24 substances), Benzidine-based Precursors (2 substances), Benzidine-based Cationic Indicators (2 substances), and Benzidine derivatives (5 substances).

One Benzidine-based Acid Dye (Acid Red 111) and 1 Benzidine-based Direct Dye (Direct Black 38) were previously assessed during the Challenge Initiative of the CMP. It was concluded that Acid Red 111 and Direct Black 38 did not meet the criteria under section 64 of CEPA 1999. No significant new information was identified for Acid Red 111 or Direct Black 38 following the Challenge assessments, and therefore these substances were not included in the current screening assessment.

One of the substances in this subgroup, TDBD (CAS RN 1871-22-3) was previously assessed in April 2008 as part of an assessment of 145 PBiT substances. That assessment identified a potential ecological concern with respect to new uses for TDBD and, therefore, the Government of Canada applied the SNAc provisions to this substance. The current screening assessment concludes that this substance is no longer of concern to the environment, nor considered as having health effects of concern. Consequently, an order was published in the Canada Gazette, Part II in March 2015 rescinding the requirements under the SNAc provisions of CEPA 1999 for this substance.

In June 2013, the draft screening assessment was released and the related notice was published in the Canada Gazette, Part I: Vol. 147, No. 25 - June 15, 2013 for a 60-day public comment period.

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