1,3,5-tris(2,3-dibromopropyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione

Long-term toxicity to fish

Administrative data

Endpoint:

fish early-life stage toxicity

Type of information:

experimental study planned

Justification for type of information:

TESTING PROPOSAL ON VERTEBRATE ANIMALS

NON-CONFIDENTIAL NAME OF SUBSTANCE:
- Name of the substance on which testing is proposed to be carried out: AP 729; 1,3,5-tris(2,3-dibromopropyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione.

CONSIDERATIONS THAT THE GENERAL ADAPTATION POSSIBILITIES OF ANNEX XI OF THE REACH REGULATION ARE NOT ADEQUATE TO GENERATE THE NECESSARY INFORMATION:
- Available GLP studies: No studies conducted according to OECD Guidelines on fish are available for the considered substance.
- Available non-GLP studies: There are no non-GLP aquatic toxicity studies available for the considered substance.
- Historical human/control data: No human data exist on AP 729.
- (Q)SAR: At our current knowledge, we are not aware of recognised validated (Q)SAR methods adequately covering all the key aspects of this endpoint and resulting in a reliable prediction of aquatic chronic toxicity.
- In vitro methods: At present, there are no EU/OECD guidelines for in vitro tests of relevance to aquatic toxicity or validated fish cell systems available. [Ref: “Chapter R.7b: Endpoint specific guidance” Version 4.0. June 2017. ECHA]
- Weight of evidence: There would be sufficient data available to develop an aquatic toxicity weight of evidence approach.
Environmental distribution of AP 729 has been evaluated by means of Level III Fugacity Model (EPIWEB 4.1) and the calculated mass amounts are:
• Air = 0.524%
• Water = 1.63%
• Soil = 12.8%
• Sediment = 85%
According to the distribution modelling estimation, the aquatic compartment exposure to AP 729 is expected to be negligible. Moreover, direct environmental exposure to AP 729 is unlikely: after the application phase, the substance is incorporated into the product matrix and unavailable for exposure (see also the paragraph “Substance-tailored exposure driven testing” of the testing proposal). Furthermore, even if on a worst-case AP 729 was indirectly released in the environment, low concentrations are expected as the additive load in final products is low and only a small fraction would be actually bioavailable due to the physicochemical properties of the substance (especially molecular size/weight > 700 g/mol) which lead to unlikely uptake. Moreover, AP 729 cannot be considered to be persistent in the aquatic environment: a hydrolysis test performed according to OECD Guideline 111 (Hydrolysis as a function of pH, Adopted: 13 April 2004) demonstrated that the substance is hydrolytically unstable due to 93.47% degradation in pH 4 buffer, 91.95% degradation in pH 7 buffer and 93.50% degradation in pH 9 buffer test solutions respectively and no formation of breakdown products was observed (preliminary test conducted at 50°C for 5 days). In a Tier 2 test, the hydrolysis of the test item was investigated as a function of pH (4, 7 and 9) at three temperatures: 20 ± 0.5°C, 35 ± 0.5°C and 50 ± 0.5°C. At pH 4, 7 and 9, the total rate constant and half-life of the reactions at 25°C were calculated and found to be 0.2409 hour-1 and 2.88 hours, respectively.
- Grouping and read-across: At our current knowledge, we are not aware of possible grouping or read-across evidences.
- Substance-tailored exposure driven testing [if applicable]: The percentage of substance AP 729 within the polymers is typically low and once it is incorporated within the matrix in the form of an article it is unavailable for exposure.
- Approaches in addition to above [if applicable]: Not applicable.
- Other reasons [if applicable]: None identified.

CONSIDERATIONS THAT THE SPECIFIC ADAPTATION POSSIBILITIES OF ANNEXES VI TO X (AND COLUMN 2 THEREOF) OF THE REACH REGULATION ARE NOT ADEQUATE TO GENERATE THE NECESSARY INFORMATION:
- According to Reach Regulation Annex IX, section 9.1., column 2, a long-term toxicity testing shall be proposed by the registrant if the chemical safety assessment according to Annex I indicates the need to investigate further the effects on aquatic organisms. In the present case, a long-term aquatic toxicity study on fish is considered since the substance AP 729 is poorly water soluble. However, it is unlikely that aquatic toxicity will occur since AP 729 is unavailable for environmental exposure (see paragraphs: “Substance-tailored exposure driven testing” and “Weight of evidence”).

FURTHER INFORMATION ON TESTING PROPOSAL IN ADDITION TO INFORMATION PROVIDED IN THE MATERIALS AND METHODS SECTION:
- Details on study design/methodology proposed: Fish Early Life Stage (FELS) toxicity test (OECD TG 210) should be regarded as the most suitable test guideline for addressing the information requirements related to fish long-term testing under REACH. Therefore, a test according to OECD Test Guideline 210 is proposed to cover the present endpoint.

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 210 (Fish, Early-Life Stage Toxicity Test)

Test material

Test material information

Constituent 1

Reference substance name:

1,3,5-tris(2,3-dibromopropyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione

EC Number:

257-913-4

EC Name:

1,3,5-tris(2,3-dibromopropyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione

Cas Number:

52434-90-9

Molecular formula:

C12H15Br6N3O3

IUPAC Name:

tris(2,3-dibromopropyl)-1,3,5-triazinane-2,4,6-trione

impurity 1

Reference substance name:

unknown impurities

IUPAC Name:

unknown impurities

Test material form:

solid: particulate/powder