Registration Dossier

Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
PNEC aqua (freshwater)
PNEC value:
0.116 µg/L
Assessment factor:
1 000
Extrapolation method:
assessment factor
PNEC freshwater (intermittent releases):
1.16 µg/L

Marine water

Hazard assessment conclusion:
PNEC aqua (marine water)
PNEC value:
0.012 µg/L
Assessment factor:
10 000
Extrapolation method:
assessment factor

STP

Hazard assessment conclusion:
PNEC STP
PNEC value:
1 mg/L
Assessment factor:
10

Sediment (freshwater)

Hazard assessment conclusion:
PNEC sediment (freshwater)
PNEC value:
0.51 mg/kg sediment dw
Extrapolation method:
equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:
PNEC sediment (marine water)
PNEC value:
0.051 mg/kg sediment dw
Extrapolation method:
equilibrium partitioning method

Hazard for air

Air

Hazard assessment conclusion:
no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:
PNEC soil
PNEC value:
0.118 mg/kg soil dw
Extrapolation method:
equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential to cause toxic effects if accumulated (in higher organisms) via the food chain

Additional information

For this substance, only acute toxicity test results are available. In none of these tests, toxic effects were seen up to the highest tested dose which was equal to the water solubility of the substance. Therefore, all PNECs derived based on the currently available information will be unrealistically low. This is substantiated by the information from the ECHA Guidance on Risk Characterisation (Part E) which states that one of the situations in which it is not possible to derive a PNEC is the case in which no effects are observed in short term tests.

Conclusion on classification

Acute aquatic toxicity tests on Daphnia magna, fish and algae evaluating the toxicity towards the reaction mass of t-butylphenyldiphenyl phosphate and bis-t-butylphenylphenyl phosphateare available. In these tests, no toxic effects are seen up to water solubility limits (0.116 mg/L) of the substance. Therefore, no classification for acute aquatic toxicity is deemed necessary.

 

With regard to the chronic aquatic toxicity, no long-term toxicity tests on the reaction mass oft-butylphenyldiphenyl phosphate and bis-t-butylphenylphenyl phosphateare available. Therefore, the classification of the substance was determined based on the criteria listed in Table 4.1.0 (b)(iii) Substances for which adequate chronic toxicity data are not available. Based on the fact that there is no toxicity up to water solubility limits (0.116 mg/L) and the substance is readily biodegradable, no chronic classification is warranted either.

 

Nevertheless, relevant available information on similar substances/multi-constituents and information on individual constituents has to be considered for the determination of the classification as well.

 

Use of information on similar substances/multi-constituents:

Information on a read-across substance (Reaction mass of t-butylphenyldiphenyl phosphate and

bis-t-butylphenylphenyl phosphate and triphenyl phosphate)is available. However as this read-across substance contains significantly more TPP (typically 43% instead of < 10%) and TPP is the only constituent identified as hazardous for the aquatic environment, this information is not considered suitable for read-across purposes in this case.

 

Use of information on individual constituents present in the multi-constituent:

The only constituentrelevant for the determination of the classification is triphenyl phosphate. According to the dissiminated REACH Registration dossier of triphenyl phosphate, TPP is classified as Acute Aquatic Cat. 1 / Chronic Aquatic Cat. 2. Based on this information, the reaction mass oft-butylphenyldiphenyl phosphate and bis-t-butylphenylphenyl phosphate would not require classification when the TPP concentration in the multi-constituent is less than 2.5%. When the TPP concentration is>2.5% but < 10% the substance would be classified as Chronic Aquatic Cat. 3 based on this information.

However, when the long-term toxicity information on TPP is evaluated more in depth, it appears that the TPP tests were performed using solvents as vehicle to administer the test substance to the test matrix. It is recognized by several instances (e.g. OECD Guidance document on difficult to test substances (ENV/JM/MONO(2000)6)) that the use of solvents for the determination of the aquatic toxicity is not preferred as solvents might significantly influence the behavior or the test substance in the medium and consequently not represent the actual toxicity of the substance of concern. Solvents can lead, for example, to emulsion formation which could cause physical effects. Water Accommodated Fraction for example are preferred test designs for the evaluation of poorly water soluble substances. 

Environmental classification in function of the DSD criteria:

 

Based on the acute aquatic toxicity information available (no aquatic toxicity up to water solubility limits) and the fact that the substance is readily biodegradable, the substance is not to be classified for environmental effects.