Notice of objection filed by RIKEN TECHNOS CORP and Minister’s response to the Notice of objection

Minister's response to RIKEN TECHNOS CORP

Notice of objection

July 11, 2022
The Honourable Steven Guilbeault
Minister of the Environment
c/o Christina Paradiso
Executive Director Chemicals Management, Environmental Protection Branch

Department of the Environment
351 Saint-Joseph Boulevard, Gatineau, Quebec K1A 0H3

Email: ec.interdiction-prohibition.ec@ec.gc.ca

Re: Notice of Objection and Request for Board of Review in relation to proposed regulations prohibiting the manufacture, use, sale and import of decabromodiphenyl ethane (DBDPE, CAS Registry Number 84852-53-9) and while providing exemptions to the prohibitions, Canada Gazette, Part I, Volume 156, Number 20 – May 14, 2022: Prohibition of Certain Toxic Substances Regulations, 2022.

Dear Minister Guilbeault:

RIKEN TECHNOS CORP. writes to express our formal objection to the above-referenced regulatory proposal.

RIKEN TECHNOS CORP. manufactures and sells thermoplastic compounds and films.

The fields in which we provide our products are diverse, including transportation equipment such as automobiles, electrical / electronic equipment, building materials / living materials, and medical care.

Among these fields, especially in the fields of transportation equipment, electrical and electronic equipment, and building materials, many DBDPEs have been used for many years for materials that require a high degree of flame retardancy.

Specifically, we include flexible flat cables for in-vehicle wiring, wire harness wires for in-vehicle wiring, corrugated tubes for in-vehicle wiring, non-combustible certified design films for various home appliances, and non-combustible certified design films for building materials.

Our company has two production bases in North America and six in Asia, and although we do not sell our products using DBDPE directly to Canada, but electric wires, tubes, design films, etc. are used our products, and final products using these parts (automobiles, household electrical / electronic products, building interiors, etc.) are also supplied to Canada.

DBDPE is used to satisfy the high flame retardancy required by UL1581, UL94, ISO6722, etc., and we are enthusiastically studying alternatives, but they have not been completed at this time. If considering switching to other brominated flame retardants currently on the market, existing substances have a low bromine ratio, so the amount of alternative flame retardant is expected to be 1.2 to 1.3 times that of DBDPE.

However, flame retardant manufacturers do not currently have sufficient production capacity to supply alternative candidates, and there are no plans to increase production in the future. For this reason, we and other companies in the same industry are very concerned about the supply problem of highly flame-retardant parts in each field, if DBDPE is subject to regulation.

Especially in automotive applications, it is used in more than 70% of all Japanese and American OEM vehicles manufactured and sold in the United States-Mexico Canada Agreement (USMCA) (formerly NAFTA) region.

We believe that it will have a huge impact on Canada as well as provided for by section 332(2) of CEPA 1999, RIKEN TECHNOS CORP. is filing this Notice of Objection and respectfully request that a Board of Review be established, pursuant to section 333 of CEPA 1999, to “inquire into the nature and extent of danger” posed by DBDPE and for the reasons set out below.

Proposed Risk Management Measures May Lead to Severe Risk to Public Health and Safety

DBDPE performs a valuable function by reducing the flammability of the products where it is used. Those products include not just consumer devices and appliances, but also include airplanes and motor vehicles. In the absence of alternatives, the prohibitions pose a genuine risk of increasing flammability of those products therefore creating a severe risk to public health and safety.

Proposed Risk Management Measures for DBDPE are Not Aligned with Other Regulatory Agencies or Agreements

The proposed risk management measures as set out in the proposed Prohibition of Certain Toxic Substances Regulations, 2022 (the “draft Regulation”) for DBDPE are an outlier globally. No regulatory authority in the world has proposed risk management measures as sweeping as those set out in the draft Regulation. Canada is acting alone to prohibit DBDPE. By way of example, the United States Environmental Protection Agency (U.S. EPA) is not currently conducting a risk evaluation for DBDPE and is not contemplating risk management measures.

ECCC has noted that Canada is a party to the Stockholm Convention on Persistent Organic Pollutants (POP), and that the proposed risk management measures would allow Canada to meet “its international commitments implementing amendments to the Stockholm Convention.” Yet, DBDPE is not listed as a POP under the Stockholm Convention. ECCC also cites meeting the goals of the Great Lakes Water Quality Agreement as a justification for its proposed risk management measures, even though DBDPE is not listed as a Chemical of Mutual Concern as part of the agreement. Accordingly, neither rationale justifies the proposed risk management measures.

Last, the Final Screening Assessment of DBDPE (the “Final Screening Assessment”) published in the May 11, 2019 Canada Gazette, Part I, as well as the Proposed Order to add the substance to Schedule 1 of the Canadian Environmental Protection Act, 1999 published in the June 29, 2019 Canada Gazette, Part I Notice, and the subsequent draft Regulation are inconsistent with the U.S.-Mexico-Canada Agreement (USMCA), which requires a risk-based approach to chemical regulations.

Any risk management measures for DBDPE need to align with other national and international regulatory bodies and with international agreements to avoid potential unintended consequences that could negatively affect Canadian consumers and businesses operating in Canada.

Proposed Risk Management Measures May Lead to Supply Chain Disruptions

Product manufacturers operate in a global regulatory environment and must take into account a broad range of product safety and design factors. This includes considerations related to product certification, performance, use and end of life, and even chemical registration. These regulatory, design, and performance requirements are addressed through a complex global supply chain for components and subcomponents.

A 2020 socioeconomic study commissioned by ECCC on DBDPE in the Canadian market noted that “at this time, effective fully tested alternatives are not currently known for many critical applications.” ECCC suggests that its consultations with industry stakeholders have helped it develop permits and exemptions to address the lack of available alternatives to DBDPE. However, these permits and exemptions are insufficient in addressing the lack of available alternatives for DBDPE. ECCC notes several times during the draft Regulation that there is a lack of data and certainty regarding cost and availability of alternatives to DBDPE for some critical applications, and consequently that compliance costs have not been estimated for proposed risk management measures affecting wire and cable, automotive products, and other applications.

The engineering and certification of products is a time-consuming process that can take years, and there are considerable financial costs involved in this effort. RIKEN TECHNOS CORP. design products to meet relevant safety standards and to be safe when used as intended. Given the lack of available alternatives for DBDPE and unknown costs of compliance with the regulatory proposal, ECCC must revise its approach in regulating DBDPE to avoid disruptions to an already overburdened supply chain.

Final Screening Assessment for DBDPE Ignores the “Weight of the Evidence”

Section 76.1 of Canada Environmental Protection Act (CEPA) requires equal weight in the application of both the weight of evidence and the precautionary principle in conducting the evaluation of the scientific evidence relating to any particular substance. Section 76.1 does not give precedence to either of these two principles. The application of the precautionary principle is not stated or intended to govern decision-making.

The conclusion reached in the Final Screening Assessment that DBDPE has the potential to transform into lower brominated products that could pose a risk to aquatic organisms conflicts with the proper application of the weight of evidence approach and has not been substantiated. ECCC reached its conclusion regarding the potential for breakdown of DBDPE based on a theory that the DBDPE would behave in the same way as another flame retardant, decabromodiphenyl ether (decaBDE). That conclusion is inconsistent with the available evidence on DBDPE.

The approach taken by ECCC is contrary to the statutory requirement to apply the weight of evidence approach. DBDPE is very different scientifically and structurally than decaBDE. Thus, the use of decaBDE as a proxy for DBDPE in computer modelling to draw this conclusion of potential breakdown products in the absence of any supporting studies is not appropriate and based on faulty assumptions given their different molecular structures.

The Conclusions of the Final Screening Assessment upon which the Proposed Risk Management Measures for DBDPE Rely is not Supported by the State of the Science

ECCC notes for the Final Screening Assessment that “given the available information on potential human health effects, DBDPE is not a concern for human health.”^{Footnote 1}  A comprehensive list of 50 analytical, toxicological, environmental, and pharmacological studies were conducted on DBDPE to evaluate its safety and to register as appropriate in other jurisdictions. These studies were provided to ECCC through the assessment process to assist in the evaluation of this substance. The state of the science as demonstrated by these studies does not support a conclusion that would justify the proposed risk management measures.

In addition to the studies discussed above, there is new scientific information since publication of the Final Screening Assessment in May 2019 that was not available and therefore not evaluated by ECCC or HC during the Screening Assessment. This additional scientific information provides a sufficient justification for the Minister to reconsider the conclusion reached in the Final Screening Assessment that DBDPE is “toxic” under CEPA.

First, in November 2020, an independent third-party review was provided to ECCC of the available scientific reports, as well as the draft and final screening assessments, for the purpose of providing an opinion on the validity of the approach taken and conclusions reached by ECCC with respect to DBDPE. Below are several of the conclusions from the independent review:

• DecaBDE is not a good read-across substance for the purpose of estimating the rate of potential debromination of DBDPE;
• Guidelines and recommendations for applying a read-across approach exist but were not adequately followed by ECCC in the Final Screening Assessment; and,
• The Final Screening Assessment does not include evidence to substantiate that lower-form DBDPE products enter the environment in a quantity or concentration that have or may have an immediate or long-term harmful effect.

Second, the National Academy of Sciences, Engineering, and Medicine (“NAS”) published a study report^{Footnote 2}  in May 2019 to determine if organohalogen flame retardants (“OFRs”) – which includes DBDPE – could be divided into subgroups based on similar chemical structures or physicochemical properties for the purposes of further assessment. NAS recommended dividing 161 OFRs into 14 subclasses. It is noteworthy that in the study, NAS grouped DBDPE and decaBDE into separate subclasses. This finding further supports the position that it is not appropriate to use decaBDE as a surrogate for DBDPE to draw any conclusion regarding potential breakdown products in the absence of supporting studies.

Third, the results of a 2,000-hour study modelling the photodegradation of DBDPE within high impact polystyrene (HIPS) and polypropylene (PP) in the Canadian environment has been shared with ECCC. Conclusions from that study are that DBDPE has a long half-life under realistic photodegradation conditions, any formation of lower brominated products from DBDPE is negligible and are not the species of concern expressed by ECCC, and lower form brominated products can be prevented with the help of ultraviolet absorption and light stabilizers.

The 50 studies previously shared with ECCC, along with new information that has been shared with ECCC since publication of the Final Screening Assessment, does not support either the finding that DBDPE is “toxic” under CEPA or the proposed risk management measures.

Based upon the facts and arguments set out above we ask the Minister to appoint a Board of Review to “inquire into the nature and extent of danger” posed by DBDPE.

Sincerely,

Koichi Inoue
Responsible Care Dept General Manager
RIKEN TECHNOS CORP.

Minister's response

Mr. Koichi Inoue
General Manager, Responsible Care Department
Riken Technos Corp.
kinoue@rikentechnos.co.jp

Dear Mr. Inoue:

This letter is in response to your Notice of Objection and request to establish a board of review to the publication of the proposed Prohibition of Certain Toxic Substances Regulations, 2022 (proposed Regulations), which was received by Environment and Climate Change Canada on July 11, 2022. The proposed Regulations were published in the Canada Gazette, Part I, on May 14, 2022.

I have carefully considered all the issues in your Notice of Objection, including those dealing with the nature and extent of the danger posed by decabromodiphenyl ethane (DBDPE) and the other questions and considerations that you brought to my attention. In my opinion, your Notice of Objection does not raise sufficient uncertainty or doubt in the science underlying the proposed Regulations that would warrant the establishment of a board of review under subsection 333(1) of the Canadian Environmental Protection Act, 1999 (CEPA). Therefore, I am denying your request, and I will not establish a board of review. The reasons for my decision are explained below and in the Annex to this letter.

Responses to comments in your Notice of Objection related to the outcomes of the screening assessment for DBDPE, which concluded that there is a risk of harm to the environment due to the persistence and widespread occurrence of DBDPE in the environment along with the potential for bioaccumulation and toxicity of its transformation products, are provided in the Annex.

The comments in your Notice of Objection regarding the development of the proposed Regulations have been considered alongside other comments received on these regulations. The specific points you have raised on the proposed Regulations and how they will be addressed are also summarized in the Annex to this letter. Your Notice of Objection raised specific concerns on the proposed exemptions for DBDPE, and to address these concerns, the proposed timeline of the DBDPE exemptions will be extended by an additional 10 years (i.e. extended from 5 years to 15 years for new products and from 20 years to 30 years for replacement parts) and the scope of these exemptions will be broadened to include all manufactured items and additional intermediate materials. This extended timeline will allow all stakeholders additional time for the research and development of alternatives, testing and certification, and transitioning their manufacturing and supply chains. Broadening the scope of the DBDPE exemptions will help to reduce the risk of prohibiting critical components, reduce the need to apply for permits under the proposed Regulations for non-exempted parts, and reduce compliance burden of stakeholders throughout the supply chain.

Please note that the comments on the proposed Regulations will be summarized in the Regulatory Impact Analysis Statement that will be published with the final Prohibition of Certain Toxic Substances Regulations, 2025 (2025 Regulations) in the Canada Gazette, Part II, which describe how these matters have been addressed.

I appreciate your bringing your concerns to my attention. Please accept my best regards.

Sincerely,

The Honourable Julie Dabrusin, P.C., M.P. (elle/she/her)

Annex

1) The following provides a summary of comments related to "Proposed Risk Management Measures May Lead to Severe Risk to Public Health and Safety" as set out in your Notice of Objection and the analysis of the information you have provided:

1A) In your Notice of Objection, you commented that DBDPE is used as a flame retardant to meet critical flammability standards and safety requirements in products such as consumer devices, appliances, electrical equipment, building materials, living materials, medical devices, airplanes and motor vehicles, including products that use flexible flat cables for in-vehicle wiring, wire harness wires for in-vehicle wiring, corrugated tubes for in-vehicle wiring, non-combustible certified design films for various home appliances, and non-combustible certified design films for building materials.

Flame retardant substances are generally used to meet performance-based flammability requirements. These requirements do not specify what chemical flame retardants need to be used; rather they may require a product or component to pass a laboratory test such as a cigarette smolder or open flame ignition test (ASTM 2014). Using chemical flame retardants such as DBDPE in products is one of the ways by which companies can meet flammability requirements for their products. Alternate substances as well as non-chemical-based alternatives may also be used to replace the use of DBDPE as a flame retardant in various applications.

In addition to the concerns you have raised in your Notice of Objection, a number of similar comments were received during the public comment period for the proposed Regulations. To address these concerns, the proposed timeline of the DBDPE exemptions will be extended by an additional 10 years (i.e. extended from 5 years to 15 years for new products and from 20 years to 30 years for replacement parts) and the scope of the DBDPE exemptions will be broadened to include all manufactured items and additional intermediate materials. This extended timeline will allow all stakeholders additional time for the research and development of alternatives, testing and certification, and transitioning their manufacturing and supply chains. Broadening the scope of the DBDPE exemptions will help to reduce the risk of prohibiting critical components, reduce the need to apply for permits under the Regulations for non-exempted parts, and reduce compliance burden of stakeholders throughout the supply chain.

1B) In your Notice of Objection, you provided comments that due to the lack of available alternatives for DBDPE in some products and that without suitable alternatives, increased flammability of products will create health and safety risks. In addition, you commented that existing alternatives are not suitable due to required higher loading rates and low availability from flame retardant manufacturers.

Please refer to the response to point 1A (above) respecting the extended timeline for, and broadened scope of the DBDPE exemptions.

2) The following provides a summary of comments related to “Proposed Risk Management Measures for DBDPE are Not Aligned with Other Regulatory Agencies or Agreements” as provided in your Notice of Objection and the analysis of the information you have provided:

2A) In your Notice of Objection, you noted that the proposed risk management measures as set out in the proposed Prohibition of Certain Toxic Substances Regulations, 2022 (the “draft Regulation”) for DBDPE are an outlier globally.

Canada has been one of the first countries to lead action on flame retardants and was the first country to complete a risk assessment and propose risk management of DBDPE; however, Canada is not alone and since then international action for DBDPE has been underway or has been finalized.

In March 2023, the European Union (EU), under the European Chemicals Agency (ECHA) published their Regulatory strategy for flame retardants, which has a focus on brominated flame retardants and their prioritization for restriction, including DBDPE. This document noted that:

For decabromodiphenyl ethane (EC 284-366-9, DBDPE) data was requested regarding potential bioaccumulation under substance evaluation and has been assessed by the PBT expert group. The available data, including field studies, appear to confirm the Persistent, bioaccumulative and toxic (PBT) properties of the substance.

Furthermore, on October 31, 2024, ECHA updated the substance evaluation status for DBDPE as “Concluded” and published a Substance Evaluation Conclusion and Evaluation Report that considers DBDPE to meet the Regulation on the registration, evaluation, authorisation and restriction of chemicals (REACH), Annex XIII very persistent and very bioaccumulative criteria, wide dispersive use and high aggregated tonnage concerns and the need for follow-up regulatory action at the EU level. The report notes the restriction of aromatic brominated flame retardants as proposed in ECHA’s Regulatory strategy for flame retardants appears as a logical continuation following a formal hazard identification as very persistent and very bioaccumulative for DBDPE.

On June 27, 2025, ECHA published a proposal for identification of DBDPE as a substance of very high concern (SVHC) on the basis of the criteria set out in REACH Article 57. A REACH Annex XV report was prepared by Sweden to support the proposal for identification of DBDPE as a SVHC.

In the United States (US), DBDPE is listed as a new chemical and is subject to a Significant New Use Rule, which requires manufacturers and processors to notify the US Environmental Protection Agency (EPA) before a new use for the manufacture, import or processing of DBDPE begins. In June 2021, the EPA made DBDPE subject to a Final Health and Safety Data Reporting rule pursuant to the Toxic Substances Control Act (TSCA) as part of a grouping of 30 organohalogen flame retardants being evaluated for risks by the Consumer Product Safety Commission (CPSC). In January 2024, the CPSC published Organohalogen Flame Retardant Scope Document: Polyhalogenated Benzene Aliphatic and Functionalized Subclass report (the PHBzAF subclass, which includes DBDPE) which concludes that “the PHBzAF subclass has sufficient data to proceed with risk assessment”. Furthermore, DBDPE is restricted in some consumer products under general flame retardant restrictions in some states, such as California, Maine, and New Hampshire.

In August of 2021, Australia published their assessment of DBDPE and found that DBDPE:

meets the persistence, bioaccumulation, adverse effects in aquatic and terrestrial organisms and long-range transport criteria of Annex D of the Stockholm Convention on Persistent Organic Pollutants. Therefore, on the basis of the current hazard information available, the assessed chemical could pose an unreasonable risk to the environment. 

The Australian report also recommended control measures be developed under the Industrial Chemicals Environmental Management (Register) Act 2021.

On June 26, 2025, the Australian government finalized its risk management for DBDPE after publishing a statutory public consultation on the proposed risk management for DBDPE in April 2025. The Industrial Chemicals Environmental Management Standard for decabromodiphenyl ethane (DBDPE) is a final scheduling decision to list DBDPE to Schedule 6 of the Industrial Chemicals Environmental Management (Register) Instrument 2022. Schedule 6 of this instrument lists “Relevant industrial chemicals that are likely to cause serious or irreversible harm with essential uses” and specifies the risk management measures, including prohibitions and restrictions, that apply to the relevant industrial chemical or a mixture or article containing such a chemical (Australia, 2025).

Canadian risk management for DBDPE takes into consideration actions taken in jurisdictions, including the EU and the US, with the possibility of aligning where appropriate.

2B) In your Notice of Objection, you noted that DBDPE is listed as neither a Persistent Organic Pollutant under the Stockholm Convention, or a Chemical of Mutual Concern (CMC) under the Canada- U.S. Great Lakes Water Quality Agreement (GLWQA) and therefore these drivers should not be used as rationale for the proposed prohibition.

The Regulatory Impact Analysis Statement (RIAS) published with the proposed Regulations did not indicate that DBDPE was listed to the Stockholm Convention. The RIAS also noted that not all substances that are prohibited under the current Regulations are listed to the Stockholm Convention. With respect to the GLWQA, the RIAS stated that “the parties have currently designated PFOS, PFOA, LC-PFCAs, HBCD and PBDEs, among other substances, as CMCs”. It was not stated in the RIAS that DBDPE is listed as a CMC under the GLWQA. 

Instead, the drivers to regulate DBDPE are the conclusion of the DBDPE screening assessment, and the related risk management objective outlined in the risk management approach for DBDPE: to achieve the lowest level of release of the substance into the Canadian environment, taking into account social, economic and technical matters.

2C) In your Notice of Objection, you commented that the U.S.-Mexico-Canada Agreement (USMCA) requires a risk-based approach to chemical regulations.

The DBDPE screening assessment concludes that DBDPE is toxic, persistent and results predominantly from human activities and that DBDPE is expected to contribute to the formation of persistent, bioaccumulative and inherently toxic transformation products, such as lower brominated diphenyl ethanes, in the environment. As such, at the time the risk management approach for DBDPE was published, DBDPE met the criteria outlined in the Government of Canada’s Toxic Substances Management Policy for virtual elimination from the environment (Canada, 1995).

Upon the coming into force of the Strengthening Environmental Protection for a Healthier Canada Act (S.C. 2023, c. 12) in June 2023, the virtual elimination provisions of CEPA were replaced with a new regime that remains risk based. In developing a proposed regulation or instrument respecting preventive or control actions in relation to substances added to Part 1 of Schedule 1 of the Act, priority will be given to the total, partial or conditional prohibition of activities in relation to the substance or of releases of the substance into the environment. For substances added to Part 2 of Schedule 1, priority will be given to pollution prevention actions, which may include prohibition, when managing risks posed by those substances. 

An Order adding DBDPE to Part 2 of Schedule 1 to the Canadian Environmental Protection Act, 1999 was published in the Canada Gazette, Part II, on February 26, 2025.

As indicated in the risk management approach for DBDPE, the environmental objective for DBDPE is to reduce its concentrations in the Canadian environment to the greatest extent practicable, and the risk management objective for DBDPE is to achieve the lowest level of release of the substance into the Canadian environment, taking into account social, economic and technical matters.

The high importation volumes of DBDPE into Canada, along with information on its uses, indicate potential for widespread release into the Canadian environment. Aquatic exposure to DBDPE is expected through activities such as formulation, either directly to receiving surface water or to a wastewater treatment system that discharges its effluent to a receiving surface water body. In addition, products containing DBDPE have the potential to release DBDPE at various stages of their lifecycle, including use (see house dust studies referred to in Section 10.1.1.2 and Appendix D of the DBDPE screening assessment) and disposal. Once released into the environment, DBDPE will be found mainly in sediment and soil, where it may persist for long periods of time, resulting in DBDPE build-up, as seen by rapid doubling times in sediment in the Great Lakes. 

Given the above, a regulatory prohibition is the best approach to meet the risk management objective for DBDPE, which is to achieve the lowest level of release of the substance into the Canadian environment, taking into account social, economic and technical matters.

Furthermore, there is nothing in the 2025 Regulations that contravenes the USMCA Agreement given that the addition of DBDPE to the Regulations reflects a risk-based approach based on the conclusion of the screening assessment of DBDPE.

3) The following provides a summary of comments related to “Proposed Risk Management Measures May Lead to Supply Chain Disruptions” as provided in your Notice of Objection and the analysis of the information you have provided:

In your Notice of Objection, you provided comments that global product manufacturers take into consideration regulatory, design, and performance requirements which are addressed through a complex global supply chain for components and subcomponents and significant time and costs are associated with switching to alternatives which require research and development, prototyping, performance testing, manufacturing retooling, and regulatory compliance certification. Furthermore, you commented that the prohibition of DBDPE proposed in Canada poses a challenge to global supply chains and exemptions are sufficient for stakeholders due to the lack of available alternatives for DBDPE in some products and unknown costs throughout the global supply chain.

Please refer to the response to point 1A (above) respecting the extended timeline for, and broadened scope of the DBDPE exemptions.

With respect to the estimated cost for transitioning to alternatives, it is acknowledged that the analysis does not monetize the full impact of the 2025 Regulations due to the limited information available on these substances and their possible alternatives. In response to these comments, a sensitivity analysis was done in the RIAS accompanying the 2025 Regulations to consider higher costs based on available information.

4) The following provides a summary of comments related to “Final Screening Assessment for DBDPE Ignores the Weight of the Evidence” as provided in your Notice of Objection and the analysis of the information you have provided:

4A) In your Notice of Objection, you comment that the conclusion reached in the Final Screening Assessment that DBDPE has the potential to transform into lower brominated products that could pose a risk to aquatic organisms conflicts with the proper application of the weight of evidence approach and has not been substantiated. 

The assessment of DBDPE draws on the available empirical, modelling, and scientific information for DBDPE. In the absence of certain data on DBDPE, information on its close analogue, decaBDE was used to evaluate certain properties of DBDPE and its potential to cause adverse effects in the environment including breaking down to lower brominated products. A weight of evidence approach is applied with consideration of multiple lines of evidence, and some uncertainty associated with data gaps in the assessment warranted application of precaution. Thus, weight of evidence, precaution and impact of uncertainty have all been considered in decision-making.

4B) In your Notice of Objection, you commented that it is incorrect in the assessment that decabromodiphenyl ether (decaBDE) is identified as an analogue for decabromodiphenyl ethane (DBDPE).

The use of analogues and read-across in risk assessment, much like decaBDE is used in the DBDPE screening assessment, is well established and internationally recognized. Canada’s approach to the use of analogues and read-across in risk assessment ^{Footnote 1.0}  is consistent with OECD Guidance^{Footnote 2.0}  and the approaches used in other jurisdictions, including by the European Chemicals Agency (ECHA)^{Footnote 3.0} . 

DecaBDE is considered to be a suitably close analogue for DBDPE given the high degree of structural and functional similarities between the two substances, and the availability of relevant empirical information. In addition to Canada, the United Kingdom (UK) in 2007 and Sweden in 2024 utilized decaBDE as an analogue substance in their respective assessments of the target substance DBDPE^{Footnote 4.0} . 

Structural and functional similarities between substances have typically translated to similarities in environmental fate, behaviour, and other properties. It is noted that some differences in molecular makeup, dimensions, and configurations exist between DBDPE and decaBDE that may affect the manner in which these molecules interact with their environment; however, these differences are well within what is typical for analogue - target differences found in regulatory risk assessments.

The abundance of empirical data on decaBDE also factored into its selection as the most appropriate analogue for DBDPE. Expert judgement is applied in this process, where chemical properties, fate, or behaviour of decaBDE is read-across to DBDPE on a case-by-case (e.g., per endpoint or property) basis rather than in an absolute manner, and by taking into consideration the suitability and comparability of these attributes.

5) The following provides a summary of comments related to “The Conclusions of the Final Screening Assessment upon which the Proposed Risk Management Measures for DBDPE rely is not Supported by the State of the Science” as provided in your Notice of Objection and the analysis of the information you have provided:

5A) In your Notice of Objection, you referenced 50 studies provided during the assessment process for DBDPE screening assessment for which you stated the state of the science as demonstrated by these studies does not support a conclusion that would justify the proposed risk management measures. 

All additional experimental studies submitted (including the 50 studies provided during the assessment process), were considered in development of the DBDPE screening assessment by weighing their reliability and relevance. Those studies that were reliable and relevant to evaluating the risks posed by DBDPE to the environment were included as outlined in the final screening assessment. Thus, the information presented in these 50 studies was either considered in the final screening assessment or has no impact on the regulatory conclusion reached in the final screening assessment for DBDPE.

5B) In your Notice of Objection, you referenced a third-party review in 2020 by Dr. Gobas (the “2020 Gobas Review”), updated in 2022 (the “2022 Updated Gobas Review”), on the available scientific reports relating to DBDPE, as well as the draft and final screening assessments for DBDPE. 

You stated that the 2020 Gobas Review concluded that: 

(i) decaBDE is not a good read-across substance for the purpose of estimating the rate of potential debromination of DBDPE; 

(ii) guidelines and recommendations for applying a read-across approach exist but were not adequately followed by ECCC in the screening assessment; and, 

(iii) the screening assessment does not include evidence to substantiate that lower-form DBDPE products enter the environment in a quantity or concentration that have or may have an immediate or long-term harmful effect. 

Regarding conclusions i) and ii), please refer to the responses to points 4A and 4B (above). 

In response to conclusion iii), ECCC acknowledges that the parent structure DBDPE is highly persistent, highly insoluble in water, and highly sorptive to particulate matter while also having the potential to cause reproductive effects at high concentrations to earthworms as well as effects on plant survival and growth. As a result of these properties, DBDPE will accumulate in the environment and become a significant source of lower brominated transformation products, which have properties that suggest they are more bioaccumulative and hazardous than the parent structure DBDPE itself. Robust modelled aquatic toxicity data for potential DBDPE debrominated transformation products suggest effects at low concentrations in the range of water solubility of these transformation products. In addition, the presence of DBDPE debromination products in wastewater treatment system pond sediments near a DBDPE manufacturing plant in the U.S have been confirmed. Considering DBDPE is a high-volume substance in Canada and that its levels are known to be increasing in the environment (as seen in Great Lakes sediment), and that DBDPE in aqueous solutions or adsorbed to solid surfaces such as sand, sediment, or dust is susceptible to various naturally occurring debromination processes, the pool of potential lower brominated transformation products are environmentally significant. Therefore, it is concluded that DBDPE meets the criteria set out under paragraph 64(a) of CEPA as it is entering or may enter the environment in a quantity or concentration or under conditions that have or may have an immediate or long-term harmful effect on the environment or its biological diversity.

5C) In your Notice of Objection, you referenced new information generated since the publication of the screening assessment, a National Academy of Sciences, Engineering, and Medicine report (the "NAS" Report), that suggests that decabromodiphenyl ether (decaBDE) is not an appropriate analogue for decabromodiphenyl ethane (DBDPE).  

With regards to comments pertaining to the "NAS" Report, please refer to the responses to Key point #4B stated previously on the suitability of decaBDE as an analogue for DBDPE.  

In addition, the physical-chemical and toxicological information presented in the "NAS" Report suggests that there are substances, other than DBDPE (e.g., pentaBDE and octaBDE), that are more comparable to decaBDE with respect to a particular set of properties considered by NAS, but it does not suggest that DBDPE is incomparable to decaBDE, nor does it suggest that some metabolites formation processes between these two substances are significantly different. It is also worth noting that these subclasses of organic flame retardant substances were developed by NAS for the purposes of assessing risk to human health, and therefore, may not have considered the behaviour of these substances in the environment when forming the subclasses. Thus, the "NAS" Report finding does not directly apply to the use of decaBDE for read-across to DBDPE in the screening assessment.

As mentioned in the response to point 4B (above), it is noted that some differences in molecular makeup, dimensions, and configurations exist between DBDPE and decaBDE that may affect the manner in which these molecules interact with their environment, however, these differences are well within what is typical for analogue – target differences found in regulatory risk assessments as evidenced by three different jurisdictions making this choice (i.e., selecting decaBDE as a suitable analogue for DBDPE) in their 2007 (UK), 2019 (Canada) and 2024 (Sweden) evaluation reports on DBDPE.

5D) In your Notice of Objection, you referenced a new experimental study, 2,000-hour study modelling the photodegradation of DBDPE within high impact polystyrene (HIPS) and polypropylene (PP) in the Canadian environment, not available during the assessment process since the publication of the screening assessment which you stated that either does not support the conclusion of the assessment or provides sufficient justification to reconsider its conclusion. 

While the applied weathering conditions appear reasonable for simulation of environmental conditions and the quality of the 2,000-hour study was deemed sufficient by a submitted data quality evaluation report, this study represents only one specific type of release scenario with limited relevance to overall DBDPE environmental release and fate. DBDPE has been found in the Canadian environment and around the world. Evidence from studies with DBDPE adsorbed to solid matrices such as soil or sediment are most relevant to the fate of the substance in the natural environment. As an additive brominated flame retardant that is blended with the polymer product (rather than a reactive flame retardant chemical bonded to the polymer product), there is the possibility of release of DBDPE from these products to the environment. In addition, DBDPE may be released to air or dust by volatilization or abrasion of product containing the substance and then deposited to soil or water. Thus, the information presented in this photodegradation study with DBDPE present within a polymer matrix has no impact on the regulatory conclusion reached in the DBDPE screening assessment.