Batch 8 Substances Review
Chemicals Management Plan
August 30, 2010
Prepared by Environmental Defence
Introduction
The Canadian Government began the long-awaited process to improve the protection of Canadians against toxic chemicals. Under the Chemicals Management Plan, the government has proposed to create a science-based regulatory regime, improved screening, labeling, monitoring and enforcement of chemicals.
In May 2007, a “Challenge” to industry on high priority substances was established to examine 200 chemical substances identified as potentially harmful to human health or the environment. The Challenge is organized through Environment Canada and Health Canada, which publish information on 15 to 30 substances every three months along with a challenge to industry and stakeholders to comment on the technical profiles of each. Industry is required to provide requested information within four to six months of the Batch publication. After information is submitted to the departments, the government has six months to draft an assessment for each batch.
For Batch 8 chemicals, substance profiles were published on January 31, 2009 and industry responded to the notice by June 2, 2009. The draft risk assessments were published on January 30, 2010. At this time, 4 substances were proposed to be “toxic” and a Notice of Intent for the application of SNAc provisions to apply to another 4 substances (CAS No. 626-39-1, 944-61-6, 65140-91-2 and 68551-44-0) was also made. Final screening assessments for all 14 substances and risk management approach documents for 4 of the 14 substances were published by the federal government on July 31, 2010. Now the Government is only proposing to apply the SNAc provisions to 3 Batch 8 substances, since the analysis for CAS No. 65140-91-2 is ongoing and expected to be published on October 2, 2010. Environmental Defence has prepared this report on Batch 8 chemicals using, unless otherwise indicated, these documents. The public has until September 29, 2010 to submit comments on the proposed risk management approach documents.
Prioritization
Environmental Defence used information pertaining to the Challenge substances in Batch 8 to create a list of priorities from among the Batch 8 chemicals. All data, unless otherwise indicated, comes from the assessment and risk management documents. These priorities are as follows:
· u DTBSBP CAS No. 17540-75-9
· MAPBAP acetate CAS No. 72102-55-77
· 2-Nitropropane CAS No. 79-46-9
· u 2-Nitrotoluene CAS No. 88-72-2
· u NTA CAS 139-13-9
· Butylated hydroxyanisole CAS No. 25013-16-5
· w zinc BDBP CAS No. 2215-35-2
· Phosphonic acid, [[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]-, monoethyl ester, calcium salt (2:1) CAS No. 65140-91-2
It is important to acknowledge that the prioritization lines are not always clear and that because different organizations have different interests, it remains at the discretion of the reader to identify individual/organizational priorities. Criteria used to sort priorities by Environmental Defence are as follows:
· Changes in decision between draft and final assessments;
· Designation as persistent, bioaccumulative, and/or inherently toxic;
· Volume of use and estimated level of exposure;
· Types of exposure (pathways);
· Quantity & quality of evidence for toxicity;
· Essentiality of the uses; and
· Availability of alternatives
Potential Chemicals of Interest to Northern Communities
Note that in the assessment, the following symbols are used to identify chemicals that may be of possible concern to northern communities. As a result of these concerns are not often explicitly cited within the government assessments, the following symbols are being used by Environmental Defence to flag chemicals of potential interest on the basis of the information contained within the assessments:
May have long range transport ability in air on the basis of its persistence in this media
u May be used in oil, mining, or forestry operations on the basis of information presented
The flagged chemicals within this document are:
· uDTBSBP (CAS 17540-75-9) – used in the petrochemical sector
· 2-Nitropropane (CAS 79-46-9) – LRTP of 12 969 km based on the TaPL3 model and as presented in the original substance profile on the Challenge website
· u2-Nitrotoluene (CAS 88-72-2) – used in the petrochemical industry in other jurisdictions, LRTP of 3198 km based on the TaPL3 model and as presented in the original substance profile on the Challenge website
· uNTA (CAS 139-13-9) – used in pulp and paper processing and oil extraction
· uZinc BDBP (CAS 2215-35-2) – used in the petroleum sector
Glossary
Given the use of numerous abbreviations within the assessment documents, a glossary has been prepared and can be found in Appendix A of this document. A glossary of international classifications follows in Appendix B.
uPhenol, 2,6-bis(1,1-dimethylethyl)-4-(1-methylpropyl)- (DTBSBP) CAS No. 17540-75-9
Categorization / Draft / FinalPBiT and believed to be in commerce in Canada.
. / Proposed that “DTBSBP meets one or more of the criteria set out in section 64 of the Canadian Environmental Protection Act, 1999””. / Concluded that “DTBSBP meets one or more of the criteria set out in section 64 of the Canadian Environmental Protection Act, 1999” because of P, B, and presence due to human activities.
Manufacture & Use
DTBSBP is not naturally produced in the environment. Consistent with the draft, there was no manufacture was reported for 2006, but 16 686 kg was imported into Canada by five companies. The amount imported within consumer products was not reported. It is a US and OECD HPV chemical and an EU LPV chemical. It is also on the Oslo-Paris (OSPAR) Commission’s list of substances of possible concern. In Canada, it is used in plastics product manufacturing and brake fluid, with other uses being considered confidential. It may be used in the ink resin and petrochemical industries, and in PVC films used for wrapping meat and produce. It is replacing the antioxidant butylated hydroxytoluene (BHT) in several non-food applications (e.g., foam industry).
Releases
As stated within the draft, no company reported air, water, or soil release, but some reported transfers (less than 100 kg in total) in non-hazardous waste to an off-site waste management facility. Data presented for percentage losses differed slightly, often just by 0.1% for those types of losses affected (e.g., wastewater, incineration, and air). Estimating releases from the waste management sites was stated as not being possible with the model.
Environmental Concerns
Partitioning data differs, as modelling in the final suggesting that on 36.4% will remain in air if released there; the draft suggested that 74% of would remain. Its affinity for soils and sediments, as well as the expectation that it be undissociated in water bodies at environmentally relevant pH (6–9) remained. In accordance with the draft, it was not expected to be persistent in air, but in water, soil, and sediment. LRTP data was different despite using the same TaPL3 model and the same input values; the draft suggested a maximum air travel distance by 63% of the substance of 131 km while the final suggested that value to be 259 km. Both values are considered low, although the latter is closer to that calculated by the OECD (280 km). Analogue (CAS 732-26-3, CAS 4130-42-1) empirical and modelled bioaccumulation data is consistent with the draft. While modelled data for DTBSBP showed different draft-final values (e.g., draft vs. final median BCF = 22 387 vs. 15 135 L/kg, draft vs. final media BAF = 870 963 vs. 407 380 L/kg). The conclusion that DTBSBP is bioaccumulative according to the criteria is consistent between the draft and final assessments. Like the draft, all but one modelled result suggested the potential for aquatic organism harm following short-term (acute) and longer-term (chronic) exposure at relatively low concentration. As per responses to public comments, model predictions for the four most likely metabolites suggest they are less toxic than DTBSBP and not bioaccumulative. One model prediction for earthworm suggested no effects at DTBSBP saturation.
Like the draft, no RQs were calculated although it was stated that given DTBSBP’s importation volumes, persistence, bioaccumulation, and toxicity, it is a substance that “has the potential to cause ecological harm in Canada”.
Health Concerns
A health assessment was also conducted. Human exposure is predicted to mostly occur via inhalation from consumer products. Consistent with the draft, MOEs were calculated using the analogue CAS 732-26-3’s NOEL for non-neoplastic effects. The MOEs were 1720 (oral exposure, upper-bounding estimate of daily intake - toddlers, foam-filled furniture) and 25 800 (oral exposure, probable daily intake – meat and produce packaged in plastic).
Existing Controls
In Canada, there are “no known risk management measures related specifically to DTBSBP”. However, there are general ones (e.g., the safety food packaging is controlled under the Food and Drugs Regulations). Internationally, it is included in the US EPAs Toxic Substances Control Act inventory, but it is listed as an effective food contact substance at a maximum concentration in the US. It is on the European Inventory of Existing Commercial Chemical Substances and considered hazardous for the environment as per the Safety Data Sheets Directive (91/155/EC). It is listed as a substance of possible concern by the Oslo-Paris (OSPAR) Commission.
Alternatives
The category of substance of which it is a part (alkylphenols) may contain some potential substitutes, but likely have similar environmental characteristics of DTBSBP. Note that DTBSBP is used as an alternative to BHT in several applications. According to a response to public comments, potential alternatives will be considered in the risk management process.
Risk Management
It is proposed for addition to the Toxic Substances List (TSL). The risk management objective is to “minimize releases of the substance to water and soil to the greatest extent practicable”. To do so, it is considering:
- Virtually eliminating releases to the environment via regulatory controls.
- Prohibiting and/or limiting “the conditions under which the substance may be imported, manufactured or used” via regulation.
- Assessing the “potential for DTBSBP to meet the criteria set out in section 200 of CEPA1999 in the event that it was to enter the environment as a result of an environmental emergency.”
As per responses to public comments, the Prohibition of Certain Toxic Substances Regulation was identified as one potential risk management instrument and removal from commerce would be considered if measurable releases cannot be prevented. Thus it seems option 2 is dependent on the success of option 1.
Methylium, [4-(dimethylamino)phenyl]bis[4-(ethylamino)-3-methylphenyl]-, acetate (MAPBAP acetate) CAS No. 72102-55-77
Categorization / Draft / FinalPBiT and believed to be in commerce in Canada. / Proposed that “MAPBAP acetate meets one or more of the criteria set out in section 64 of the Canadian Environmental Protection Act, 1999”. / Proposed that “MAPBAP acetate meets one or more of the criteria set out in section 64 of CEPA 1999”.
Manufacture & Use
As with the draft, MAPBAP acetate is neither naturally produced in the environment nor manufactured in Canada in 2006; however, 10 001 - 100 000 kg was imported and used. Quantifying the amount that may also be imported in manufactured items or in quantities below the 100 kg reporting threshold was determined not possible due to insufficient information. It is reportedly used as a paper dye, with another use being considered confidential.
Releases
Consistent with the draft, no company reported releases to the environment. Estimates of loss differed between draft and final. To expand, draft-final differences are as follows: loss to recycling (41%vs. 47.10%), landfills (39.5%vs. 43.82%), wastewater (18.3% vs. 7.72%), and incineration (1.2% vs. 1.36%). What accounts for the difference is not clear.
Environmental Concerns
As per the draft, MAPBAP acetate is anticipated to mostly partition into water. While it appears one less biodegradation model was considered the final, 5 of 6 (as opposed to 6 of 7) models, suggest persistence in water, soil, and sediment. In the final, it was stated that MAPBAP acetate carbocation persistence would be similar and that “chemical speciation (ionic vs. neutral form) is less relevant for biodegradation predictions than for bioaccumulation and toxicity predictions”. Slow biodegradation is supported by findings that dyes are essentially non-biodegradable under aerobic conditions. LRTP, as per the original profile on the Challenge website, is expected to be moderate (444 km) based on the TaPL3 model. The bioaccumulation data and conclusion of MAPBAP not meeting the regulations was consistent between draft and final assessments. The toxicity data for 2 of its analogues and conclusion that “MAPBAP acetate is expected to cause harm to aquatic organisms at relatively low concentrations” is also consistent between the draft and final. Only ecological effects in water were investigated as there was no data for elsewhere.
The ecological risk assessment differed. Instead of 11 industrial sites, 10 pulp mill sites were considered and industrial loss to water went from 23.3% to 8.3%. According to a response to a public comment, this revised release is based on an OECD and Development Emission Scenario Document that takes water recycling within the pulp mill into account. The final PECs were higher, ranging from 0.00575 mg/L to 0.0543 mg/L in water. The final PNEC was also higher. The final was 0.003 mg/L (experimental LC50 of 0.332 mg/L for the rainbow trout) while the draft was 0.001 mg/L (experimental LC50 of 0.1 mg/L for medaka fish). A new LC50 was used because the assessors determined that the most reliable study for acute toxicity was for Malachite Green for Rainbow Trout. Final assessment worst-case RQs ranged from 1.5 to 18.1 and 8 of 10 best-case RQs ranged from 1.2 to 3.6. The conclusion that “MAPBAP acetate could be causing ecological harm in Canada” remains.
Health Concerns
Population exposure was still anticipated to be negligible-low. The estimated total daily intake from environmental media (mainly soil ingestion) was slightly greater in the final (0.039 vs. 0.01 μg/kg-bw per day) although estimated oral acute intake from paper ingestion remained 0.067 mg/kg-bw per event. The other health assessment data was consistent, including modelled predications for carcinogenicity, genotoxicity, developmental toxicity, and reproductive toxicity, as well as information about similar triarylamine substances.
Existing Controls
There are no known, MAPBAP acetate-specific risk management measures in Canada. However, the prohibition of acutely lethal effluent, and release limits for biochemical oxygen demand (BOD) and total suspended solids (TSS) from pulp and paper mills effluents are regulated by the Pulp and Paper Effluent Regulations (PPER) of the Fisheries Act. It is allowed in non-food use pesticide products by the US EPA. It is also on the US EPA’s Toxic Substances Control Act (TSCA) and the New Zealand’s chemical inventory.