Summary of public comments received on the first draft screening assessment and risk management scope for boric acid, its salts and its precursors

Comments on the 2016 first draft screening assessment and first risk management scope for boric acid, its salts and its precursors, assessed under the Chemicals Management Plan (CMP), were submitted by the Canadian Consumer Specialty Products Association (CCSPA); the Canadian Cosmetic, Toiletry and Fragrance Association (CCTFA) (now Cosmetics Alliance); Ecolab; Etimine USA; the Industry Coordinating Group for CEPA; the Mining Association of Canada (MAC); Nalco Canada; Procter & Gamble Inc.; Quadra Chemicals Ltd.; Rio Tinto (Rio Tinto Minerals / US Borax); S.C. Johnson and Son Ltd.; and SMC (Canada) Ltd.

Summarized public comments and responses are provided below, organized by topic.

Scope and information gathering

Comment Summary 1: Several stakeholders were concerned that there was no advanced notice or consultation regarding the expansion in screening assessment scope from 14 substances to over 100 substances. Advanced notice on the expansion in scope would have allowed stakeholders to submit input for these substances prior to publication of the first draft screening assessment. Stakeholders requested the opportunity to submit information on these additional substances.

Response 1: A moiety-based approach for the first draft screening assessment was communicated publicly and to stakeholders. As both the first draft screening assessment and updated draft assessment focus on substances with a common moiety of concern (boric acid), they include more than just the initial 14 substances that met categorization criteria. A moiety approach was taken in order to assess the potential for cumulative effects from the boric acid moiety. The updated draft assessment was developed to provide an additional opportunity for stakeholders to provide comments on the assessment. All information identified and submitted by stakeholders during the public comment period for the first draft screening assessment, including any information related to these additional substances, was considered when updating the draft assessment. 

Both the first draft screening assessment and updated draft assessment identify substances on the Domestic Substances List (DSL) and any associated hydrated forms that are salts or precursors of boric acid but do not appear on the DSL, the Revised In-commerce List, and commercially important minerals. Over 100 CAS RNs were identified as salts or precursors of boric acid, however; the scope of the assessment is not limited to the non-exhaustive list of these substances in Appendix A-1 of the updated draft assessment.

Comment Summary 2: Due to the significant expansion of scope, a survey issued pursuant to Section 71 of the Canadian Environmental Protection Act, 1999 (CEPA) should have been conducted to gather information on these substances to support the assessment.

Response 2: Thirteen substances in this assessment were included in a survey issued pursuant to Section 71 of CEPA. While these surveys are useful for gathering information, they are not the only information sources used by the program. Information from the Canada Border Services Agency (CBSA), the Canadian International Merchandise Trade Database, material safety datasheets, scientific journal publications, public websites and databases, internal Health Canada databases, Environmental Effects Monitoring (EEM) data, data from monitoring programs (including air, food, water, and human biomonitoring), and voluntary information submitted by stakeholders were used to gather information on the substances in this updated draft assessment. 

Comment Summary 3: Government officials should have early engagement with affected industries. This would increase awareness within companies and their supply chains. This would allow for more effective information-gathering activities, assessments and potential management actions.

Response 3: Noted. The substance grouping initiative was launched via a webinar followed by regular discussions with interested stakeholders leading up to and following the publication of the first draft screening assessment. Information submitted by stakeholders was considered when updating this draft assessment.

Comment Summary 4: Additional information, including a new risk assessment on boron-containing substances in cleaning products as well as an industry survey, was submitted for consideration.

Response 4: All information identified and submitted by stakeholders was considered when updating the draft assessment including the new assessment and survey on cleaning products.

Ecological assessment

Comment summary 5: A stakeholder agrees with the proposed actions to address ecological risks through communication with the provincial authority to stay updated on the latest developments with respect to the facility of concern described in Section 3.2.1 of the first risk management scope.

The stakeholder is not aware of any other facilities similar to the facility of concern and notes that action on any such facility would not be warranted as requirements for effluent toxicity testing under the Metals and Diamond Mining Effluent Regulations is an adequate safeguard against unexpected effects.

Response 5: Noted.

Comment summary 6: The summary sections of the risk assessment and risk management documents refer to the industrial classification codes for “metal mining”, which may be misleading for readers. Revisions to these sections are needed to clarify that metal mining in Canada does not lead to excessive levels of boron in effluent. The one facility identified as a concern is a custom milling facility.

Response 6: Clarification has been added to the updated draft assessment and the revised risk management scope that the mill of concern is not a conventional mine but a facility processing recovered slags for precious and base metals. A paragraph describing the NAICS definition of “mining” has been added in the metal mining exposure section in the updated draft assessment.

Comment summary 7: The final assessment and risk management document should provide updated exposure information for the milling facility of concern.

Response 7: Where available, exposure information was updated on the metal mining sector and other sectors, including the milling facility of concern.

Comment summary 8: Updated information for the facility of concern was provided on water quality and biological monitoring programs, as well as additional studies being considered to further reduce the release of boron from a tailings area.

Response 8: Data submitted by the stakeholder has been included in the exposure section of the updated draft assessment.

Comment summary 9: The ecological risk characterization is inappropriate as ecological risk from boron exposure was identified for only one facility. This site also has a Boron Reduction Strategy in place so broad regulation of boron compounds is not warranted.

Response 9: The number of facilities or sectors associated with potential ecological risk is not a consideration for concluding in assessments under CEPA.

Updated exposure information demonstrated decreased boron discharge from the mill facility of concern after adopting the Boron Reduction Strategy under provincial certificates of approval. However, measured boron concentrations in the receiving water courses and risk quotients (RQs) remained relatively high. Moderate to high concentrations of boron at 3 other facilities (corresponding to RQs of 0.78-0.95) were also considered as lines of evidence in determining the assessment conclusion. The updated draft assessment indicates that a small number of facilities may release boron to an extent that has potential to cause ecological concern.

The revised risk management scope identifies options under consideration for risk management at the mill site of concern. Further actions for other facilities in the metal mining sector are not currently under consideration.

Comment summary 10: The mill site mentioned in the first draft screening assessment is likely an outlier and does not adequately represent other operations or users of boron. It is recommended to initiate a mandatory CEPA Section 71 survey for mill sites in order to reduce any uncertainties.

Response 10: Text indicating there may be other facilities with similar operations as the mill site of concern has been removed from the updated draft assessment. A statement was added indicating that a small number of facilities within the metal mining sector may release boron to an extent that is of ecological concern.

The revised risk management scope focuses on risk management for the mill site of concern only; no risk management is proposed at this time for the mining sector as a whole.

A Section 71 survey is not necessary at this time to inform risk management options under consideration for the mill site of concern. However, this does not preclude the Government of Canada from gathering additional information on boric acid, its salts, and its precursors via a mandatory survey in the future.

Human health assessment: health effects

Comment Summary 11: The benchmark dose level (BMDL) calculated by the Pest Management Regulatory Agency (PMRA) and adopted in the first draft screening assessment using data from two 90-day dog studies represents a low incidence critical effect and thus in general is a conservative point of departure (POD).

Response 11: The dog studies are considered to be the most biologically relevant for establishing points of departure for use in the human health risk assessment. The calculated BMDL by the PMRA remains the most appropriate for use in the human health risk assessment for frequent or daily exposure, taking into account low dose testicular effects and dataset uncertainty, and being protective of effects in sensitive subpopulations.

Comment Summary 12: Health Canada should align with other regulatory agencies and use the developmental toxicity study in rats (Price et al. 1996) for their POD. The dog studies (Weir and Fisher 1972) are of inadequate quality to derive a POD for risk assessment. An alternative method to assess risk to boric acid would be to compare blood biomonitoring data in pregnant people to blood boron concentrations in pregnant rats from the developmental toxicity study (Price et al. 1996).

Response 12: While consideration is given to evaluations conducted by other regulatory authorities, differences in science policy and interpretation may result in differing outcomes with respect to individual studies, endpoint selection for risk assessment, and application of uncertainty factors. Although the dog toxicity studies have limitations, they remain the best and most relevant available data for chronic effects of boron. These studies were used in international assessments by Health Canada’s PMRA and the United States Environmental Protection Agency’s (US EPA’s) Office of Pesticide Programs. The original studies for both borax and boric acid showed consistent results with respect to testicular effects in dogs, and that these effects occurred at doses that were lower than what was reported by Weir and Fisher in their 1972 paper.

With respect to chronic, systemic effects of boron exposure, testicular effects are considered the most sensitive endpoint. Therefore, a BMDL of 2.9 mg B/kg bw/day was selected as a POD for risk characterization of frequent or daily exposure scenarios based on decreases in testicular weight in dogs. The selection of a conservative POD, together with a 3-fold database uncertainty factor, is considered protective of sensitive subpopulations, providing a margin of 1000 to the NOAEL of 9.6 mg/kg bw/day for decreased fetal bodyweight observed in the rat developmental toxicity studies. 

The no-observed-adverse-effect level (NOAEL) identified in the developmental toxicity study in rats (9.6 mg/kg bw/day) was used as a POD for exposure scenarios where exposure was intermittent and/or infrequent in the updated draft assessment based upon the sensitivity of the fetus to skeletal abnormalities following boron exposure.

Comment Summary 13: The Margin of Exposures (MOE) used by other regulatory agencies and scientific organizations is substantially lower than the target MOE of 300 for the testicular effects used in the first draft screening assessment. Based on standard risk assessment practices, MOEs greater than 100 compared to the male reproductive POD would be expected to be protective for human exposure to boron.

Response 13: While consideration is given to evaluations conducted by other regulatory authorities, differences in science policy and data interpretation may result in differing outcomes with respect to individual studies, endpoint selection for risk assessment, and application of uncertainty factors. MOEs must be adequate to address uncertainties in the health effects and exposure data used to characterize risk. Considerations may include uncertainties associated with extrapolating a POD for long-term exposure from a study of shorter duration, extrapolating from a lowest-observed-adverse-effect level (LOAEL) to a NOAEL when there is lack of a clear POD due to adverse effects observed at all doses, taking into account the steepness of the dose response, and limitations in the critical study and/or supporting data set.

For the testicular effects, the standard 10 by 10 uncertainty factors were applied to take into account the inter- and intra-species variation. An additional 3-fold uncertainty factor was applied to protect against testicular histological effects predicted to occur at doses below those doses causing decreases in testicular weight. For developmental effects, the standard 10 by 10 uncertainty factors were applied to take into account the inter- and intra-species variation. An additional 3-fold uncertainty factor was applied for increased sensitivity of the young and fetal effect severity. The NOAEL identified in the developmental toxicity study in rats (9.6 mg/kg bw/day) was used as a POD for intermittent and/or infrequent exposure to boron in the updated draft assessment due to the sensitivity of the fetus to skeletal abnormalities following boron exposure.

Comment Summary 14: The BMDL, MOEs and assumptions made in the Health Canada’s PMRA assessment should not be used in the CMP draft assessment since the exposure scenarios and profiles described in the first draft screening assessment are very different from pesticide use.

Response 14: The best and most relevant available data on the potential human health effects of boric acid and exposure of the general population were considered. This includes assessments conducted by other regulatory bodies, including the Health Canada’s PMRA, the US EPA, European Food Safety Authority, and Health Canada’s Water and Air Quality Bureau. However, only exposure scenarios that are relevant to CMP were considered in this assessment.

Comment Summary 15: The target MOE for male reproductive effects is overly conservative. Dietary intake alone would exceed the target MOE established in the first draft screening assessment.

Response 15: The acceptability of a MOE is determined by considering many factors, such as the inherent hazard of the substance and severity of health effects, the route, frequency and duration of exposure in a critical animal study, and human exposure relative to the POD selected.

Comment Summary 16: All available data on the critical effect of male reproductive toxicity should be considered when establishing the MOE. 

Response 16: The updated draft assessment does not list or describe all available data, but rather presents only the relevant information key to the risk characterization. The best and most relevant available data on the potential human health effects of boric acid, including reproductive and developmental toxicity, and exposure of the general population were considered when establishing the POD and the acceptability of the MOE.

Comment Summary 17: Health Canada should not disregard occupational studies based on the absence of data on testes histopathology in these studies. Recommendation to use available occupational studies to further refine the MOE.

Response 17: The results of occupational studies were considered in the updated draft assessment. It was determined that the results of these studies do not discount the adverse health effects observed in animal studies. Overall, study limitations preclude the use of this data in deriving a POD for risk assessment or refining the MOE. The evaluation of epidemiological studies in the updated draft assessment is consistent with other published international assessments on boron.

Comment Summary 18: Several stakeholders noted inadequate reporting or errors in the description of occupational studies.

Response 18: Additional information on occupational studies was added to the updated draft assessment to take into account comments from stakeholders and new information to enhance transparency with respect to the data, approach and assumptions used in the assessment.

Comment Summary 19: There is no scientific evidence that boric acid has a hormonal mechanism of action or the ability to cause toxicity through endocrine disruption.

Response 19: Evidence from controlled human and animal studies demonstrate changes in hormone levels following exposure to boron. These studies have been documented in the updated draft assessment.

Comment Summary 20: Additional information regarding the nutritional role of boron in humans is requested in the assessment.

Response 20: Additional information on the essentiality of boron was added to the updated draft assessment to take into account comments from stakeholders and new information to enhance transparency with respect to the data, approach and assumptions used in the assessment.

Comment Summary 21: The average dermal absorption rate for boric acid should be 0.5%, as derived by the European Union (EU) Scientific Committee for Consumer Safety (SCCS) in 2010, and not a range from 0.5% to 10%. There is no scientific rationale for the high end of dermal absorption (10%) used in the assessment. The assumption of 10% absorption rate is overly conservative and unsubstantiated.

Response 21: Based on a weight of evidence approach, a dermal absorption value of 10% was deemed appropriate for the use in the risk assessment. The dermal absorption value for boric acid of 0.5% reported by the SCCS is not corrected for low recovery in the study. The dermal absorption value of 10% selected for this assessment was based on the same in vivo human studies that were used by the SCCS as well as a 2014 in vitro study that suggests dermal absorption up to 41% for dimethylamine borane, a boric acid precursor. This value accounts for study limitations, different product formulations, and for the use of a single dermal absorption value for all forms of boron.

Comment Summary 22: Studies do not support that boric acid is 100% absorbed through broken or abraded skin.

Response 22: The available dermal absorption studies demonstrate that dermal absorption of boric acid across broken or abraded skin is less than 100% but were not of adequate quality to determine a quantitative value. The updated draft assessment has refined the dermal absorption across broken or abraded skin to 50%. This value was used for estimating exposure to products where broken or abrased skin was reasonably anticipated.

Comment Summary 23: A good laboratory practice (GLP) guideline study of dermal absorption of boron should be conducted to reduce uncertainty in the exposure assessment.

Response 23: No GLP dermal absorption guideline studies of boric acid are available in the published literature or have been submitted to Health Canada for consideration.

Human health assessment: exposure

Comment Summary 24: Boron is an essential mineral for plants, and as such is a normal dietary constituent for humans. It occurs naturally in both food and drinking water as borate or boric acid. Boron is also a common ingredient in industrial and consumer cleaning products.

Response 24: This information is presented in the updated draft assessment.

Comment Summary 25: Several stakeholders commented that the most common source of daily exposure to boron is from food or from food and drinking water.

Response 25: As boron is considered an essential micronutrient for plant growth, the exposure estimates indicate that naturally occurring boron in fruits and vegetables, and to a lesser extent drinking water, represent primary sources of background exposure. Considering that the consumption of fruits and vegetables are the primary contributors to background dietary intake of boron and the universally recognized health benefits of diets rich in fruits and vegetables, background dietary exposure from natural sources is not considered to be a concern for people in Canada.

In order to help identify potential sources of boric acid exposure for people in Canada above background levels (for example, from environmental media, food and drinking water), exposure estimates were derived for some products available to consumers in the following categories: arts and crafts materials and toys; cleaning products; do-it-yourself products; flame retardant uses; self-care products that is, cosmetics, natural health products, and non-prescription drugs); and swimming pool and spa maintenance products. Exposure estimates from products were highly variable. Some products and uses had relatively low exposure compared with background exposure, while other products and uses resulted in exposures several orders of magnitude higher than background exposure.

Comment Summary 26: Exposure from sources other than the diet, such as cleaning products used by consumers, is insignificant. Data from the Alberta biomonitoring program show that people in Canada are not exposed to boron above expected dietary background levels.

Response 26: Biomonitoring data can provide a measure of integrated exposure of the population from all routes (for example, oral, dermal, and inhalation) and sources (for example, environmental media, diet, and frequent or daily use products). Canadian biomonitoring data for boron was available from the biomonitoring programs in Alberta and Northern Saskatchewan, the Canadian Health Measures Survey (CHMS) and from a targeted study on First Nation youth in Quebec. Although biomonitoring data provides an integrated measure of exposure, it does not identify sources of exposure.

In the updated draft assessment, exposure estimates were derived from biomonitoring data as well as environmental media, food and drinking water, and from products available to consumers. This was done to identify sources of exposure and to inform risk management options, if required. Exposure from cleaning products is variable depending on the type of product (for example, general purpose cleaner, toilet bowl cleaner), formulation (for example, powder, liquid), the area of use (for example, floors, kitchen counter) and the concentration of boric acid in the product. Some cleaning products will result in minimal exposure including the use of cleaning tablets used in automated dishwashers, laundry washing machines, and toilet bowls. While other cleaning products may result in exposure much higher than background levels including powder borax formulations used as abrasives or general purpose cleaners.

Comment Summary 27: Several stakeholders were not supportive of using biomonitoring data from Europe to estimate a 95th percentile blood boron concentration as it was not representative of people in Canada, there were better available data or that it overestimated upper percentile exposure. Alternative data and approaches were recommended, including use of data from existing studies conducted in Canada, using statistical methods to better estimate a 95th percentile from multiple studies, and waiting for boron biomonitoring data from the CHMS. Many stakeholders raised concern that a sound rationale for the use of European data to estimate upper percentile exposure in people in Canada was not presented. 

Response 27: The best and most relevant human biomonitoring data were considered in the updated draft assessment. The assessment includes biomonitoring data from studies conducted in Canada and Europe. Biomonitoring data from CHMS and other Canadian data were added to the updated draft assessment which were not available at the time of the first draft screening assessment. Urine biomonitoring data from the CHMS was used to characterize risk to people in Canada. 

Comment Summary 28: The household cleaning product scenarios used to model exposure in the first draft screening assessment do not accurately represent the use rate, frequency, exposure, or risk of boron ingredients in cleaning products. Significant refinement of exposure to boron attributed to cleaning products is needed, incorporating detailed product use and exposure parameters. New exposure and risk estimates to boron from cleaning products were submitted during the public comment period on the first draft screening assessment. These incorporated accurate use information on boron in cleaning products collected from an industry survey. Exposure estimates were derived using standardized exposure models and a 0.5% dermal absorption value. The submitted exposure estimates and MOEs for cleaning products demonstrate that these products are not of concern for human health.

Response 28: Estimates of exposure to boric acid from the use of cleaning products were revised in the updated draft assessment, based upon information submitted by stakeholders, a search of publicly available information, updates to the exposure models employed and updates to the dermal absorption value. In addition to the ConsExpo Web model, algorithms from the US EPA Residential Standard Operating Procedures and the Pesticides Handlers Exposure Database (PHED) were used to estimate exposure. Product formulation type, application method and dilution rates were quantitatively incorporated into the exposure estimates. Dermal exposure estimates incorporated a 10% dermal absorption value. Estimates were refined to the best extent possible based upon available data. Exposure estimates were not amortized for frequency of use. Rather, products with infrequent or intermittent exposures were compared to the critical effect level based on developmental effects, and products with frequent or daily use were compared to the critical effect level for testicular effects.

Comment Summary 29: There is no indication that particle size was taken into account for the inhalation exposure estimate.

Response 29: Updated inhalation exposure estimates were derived using 2 models: ConsExpo Web and the PHED. In the ConsExpo Web model, exposure estimates were derived for inhalable particles up to 10 µm in size. There is no information available on the particle size from the PHED wettable powder data. This data was used as it is considered to be the best available data for estimating inhalation exposure from pouring powders. PHED data was used by the PMRA and the US EPA in their evaluations of the pesticide uses of boric acid.

Comment Summary 30: Boron use in building materials, cellulose and fiberglass insulation, engineered wood and gypsum board are either sealed, encapsulated, or isolated from consumers eliminating any exposure to borates from these materials. As a result, exposure to the consumer or general public from building materials is unlikely.

Response 30: There is potential for exposure to boric acid from the use in building materials. During DIY construction and as building materials age, these building materials can break down and contribute to the presence of boron in indoor air and dust. Exposure through this source would be captured in the biomonitoring data. In addition, boron concentration measured in house dust was incorporated into the background exposure estimates from food, drinking water and environmental media. 

Comment Summary 31: It should be clarified that the studies cited to demonstrate an increase in blood boron concentrations following the use of products containing boric acid or precursors of boric acid refer to intentional ingestion of boron supplements and are not the result of exposure to non-supplement products.

Response 31: Additional information on the biomonitoring exposure studies conducted with supplements and mouthwash was added to the updated draft assessment to address comments from stakeholders. This new information enhances transparency with respect to the data, approach and assumptions used in the assessment.

Human health assessment: risk characterization and conclusions

Comment Summary 32: Several industry stakeholders disagree with the conclusion that boric acid, its salts and its precursors meet the criteria of section 64(c) of CEPA.

Response 32: As a result of the human health risk assessment, it was determined that exposure to boric acid represents a potential concern for human health. The MOEs between the exposure estimates and the critical effect level based on reproductive and developmental effects were potentially inadequate to address uncertainties in the health effects and exposure data sets. In consideration of this information, it is proposed to conclude that boric acid, its salts and its precursors meet the criteria set out in section 64(c) of CEPA.

Comment Summary 33: The risks of exposure to boric acid should not include all sources of exposure. Rather, risk estimates should look at incremental risk above dietary exposure.

Response 33: Potential risk to people in Canada was characterized using exposure estimates derived from biomonitoring data. Biomonitoring data represents a biologically relevant measure of integrated exposure from all routes and sources. Based on this integrated exposure estimate, there is potential for harm to human health from exposure to boric acid. In addition, the updated draft assessment presents exposure estimates and MOEs from products available to consumers to better attribute sources of exposure above background and to inform risk management options, if required.

Comment Summary 34: The MOEs for exposure to boron from use of cleaning products in the new assessment submitted by stakeholders demonstrate that consumer and industrial use of cleaning products containing boron do not pose a human health concern.

Response 34: As a result of the human health risk assessment, it was determined that exposure to boric acid represents a potential concern for human health. Exposure from cleaning products is variable. Some cleaning products will result in minimal exposure while others may result in exposure much higher than background levels. The MOEs for cleaning products presented in the updated draft assessment range from 4 to greater than 300 000. MOE less than 300 are considered potentially inadequate to address uncertainties in the health effects and exposure data used to characterize risk.

Risk management

Comment Summary 35: A stakeholder requests that their opinion be considered in the determination of management actions for boric acid, its salts and its precursors.

Response 35: Risk management determinations under CEPA do include consideration of other impacts identified, in addition to identified risks. All stakeholders are provided the opportunity to comment on risk management actions. All comments are considered when selecting, developing and implementing risk management actions.

Comment Summary 36: Other international jurisdictions currently have less severe restrictions than those proposed by Canada in the risk management scope document published in 2016, regarding the use of boron in products.

Response 36: When selecting risk management options for proposed toxic substances, the Government of Canada considers international alignment. Note that the EU is considering further restrictions and has restricted the use of borax as a general-purpose household cleaner.

Comment Summary 37: Risk management should be targeted at uses that are demonstrated to pose a risk.

Response 37: The updated draft assessment presents exposure estimates and MOEs from products available to consumers to better attribute sources of exposure above background levels. Risk management options for products with exposure estimates indicating human health risk are under consideration.

Comment Summary 38: The assessment does not support that removal of the low levels of boron in laundry products will result in a meaningful reduction of risk.

Response 38: The updated draft assessment identifies risk specifically associated with certain cleaning products.

Comment Summary 39: The presence of borates in laundry products is necessary for both functionality and stability of the product.

Response 39: The claim of the necessity of borates in laundry products is noted. Nonetheless, it should be noted that some companies in the cleaning sector are considering substitutes, which implies it may not be necessary.

Comment Summary 40: Boron is already suitably managed under existing regulations in Canada.

Response 40: In view of the findings of the updated draft assessment, further risk management is required. The Government of Canada will continue to consider current federal and provincial risk management actions applicable to boric acid/boron when selecting and designing risk management measures, as appropriate.

Comment Summary 41: Note a correction is needed in the Risk Management Scope regarding the World Health Organization (WHO) guidelines for boron.

Response 41: The revised risk management scope has been adjusted to reflect this.

Comment Summary 42: A stakeholder asserts that the assessment does not establish a risk to health, or the environment associated with boron and that no mitigation is required. Adding a biologically important and essential micronutrient to Schedule 1 of CEPA is unprecedented.

Response 42: The updated draft assessment has identified a risk to the environment and human health from exposures to boron-containing substances using a weight of evidence approach. Given these identified risks, actions under federal and/or provincial jurisdictions are under consideration, as per the revised risk management scope. As such, it is proposed to recommend the addition of Boric acid, its salts and its precursors to Part 2 of Schedule 1 of CEPA, as this enables the Government to take risk management actions under the Act.

Comment Summary 43: Targeted and focused risk management commensurate with the actual risks should be undertaken, especially in view of the fact that most exposure is associated with food and water intake. As is, further clarity is required in order to show how the proposed control measures were identified.

Response 43: Specific exposures have been identified which indicate additional management measures to those already in place are needed. Exposure to boron through food and water are unavoidable, but measures are under consideration to address specific additional exposures.

Comment Summary 44: In the determination of appropriate risk management measures, other factors such as economic impacts and product utility need to be considered.

Response 44: Risk management determinations under CEPA include consideration of potential social and economic impacts, in addition to identified risks.

Comment Summary 45: In addition to including boron in the biomonitoring program, stored bio-specimens from previous biomonitoring cycles 1 to 4 since 2007 should be analyzed for boron. It is important to determine by biomonitoring if actual exposures are elevated before banning uses of important products.

Response 45: The best and most relevant human biomonitoring data were considered in the updated draft assessment. The assessment includes biomonitoring data from studies conducted in Canada and Europe. Biomonitoring data from CHMS cycles 5 and 6 were added, which were not available at the time of the first draft screening assessment. Urine biomonitoring data from the CHMS were used to characterize risk to people in Canada. 

In addition, quantification of exposures during use of certain products containing boron does show that these levels are of concern with respect to specific health effects.

Comment Summary 46: As fruit and vegetable intake comprises the largest exposure, reducing exposure from products would not meaningfully reduce risk.

Response 46: The updated draft assessment demonstrates a clear need to find measures to reduce additive exposures, such as those from use of certain consumer products highlighted in the updated draft assessment.

Stakeholder consultation and engagement

Comment Summary 47: Posting of public communications on substances at the first draft publication stage of the assessment and management documents, is premature. At this stage findings are preliminary and subject to change.

Response 47: Health Canada tries to be proactive in public communications, in particular when there appears to be a disproportionately impacted subset of the population such as children, as is the case with certain products containing boron.