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Long-term toxicity to fish

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Description of key information

No experimental data available.

Fish is not the most sensitive trophic level.

The NOEC is expected to be > 1 mg/L. No chronic effects are expected.

Key value for chemical safety assessment

Additional information

In Annex IX of Regulation (EC) No 1907/2006, it is laid down that chronic tests shall be proposed by the registrant if the chemical safety assessment indicates the need to investigate further the effects on fish. According to Annex I of this regulation, the chemical safety assessment triggers further action when the substance or the preparation meets the criteria for classification as dangerous according to Directive 67/548/EEC or Directive 1999/45/EC or CLP Regulation (EC) No 1272/2008 or is assessed to be a PBT or vPvB. The hazard assessment of the substance reveals neither a need to classify the substance as dangerous to the environment, nor is it a PBT or vPvB substance, nor are there any further indications that the substance may be hazardous to the environment.

Considering the possibility for the prediction of relative species sensitivities according to the REACH Guidance Document R.7b, chapter R.7.8.5.3, further testing on fish would not contribute to improve the current knowledge of the substance and/or its associated risk when released to the aquatic compartment. This conclusion is based on a factor of greater than 10 for fish to aquatic invertebrates.

Long-term toxicity testing is not triggered by the results of the exposure assessment and the risk characterization. The risk-characterisation ratios (RCR) do not indicate a risk for the environment (RCR < 1).

Therefore, and for reasons of animal welfare, a chronic test in fish is not provided.

Long-term toxicity to fish

Long-term toxicity data on fish are not available and are waived following a weight-of-evidence approach to justify the adaptation of the information requirements for fish of Annex IX without conducting a long-term toxicity test with fish according to Annex I and IX of Regulation (EC) No 1907/2006 and for reasons of animal welfare.

This weight-of-evidence approach includes the following information sources:

·       Acute-to-chronic ratio by ECETOC (2003)

·       Relative species sensitivity (REACH Guidance R.7b,R.7.8.5.3)

·       Data from QSAR models

 

Acute-to-chronic approach:

Acute-to-chronic ratios (ACR) have been developed by ECETOC as an alternative approach in the risk assessment to the empirically chosen assessment factors for deriving PNECs (ECETOC, 2003). Data for the calculation of ACR have been taken from the ECETOC Aquatic Toxicity database (EAT).

The expected NOECs for long-term effects on fish have been estimated by dividing the available experimental 72-h LC50 of >500 mg/Lwith the ACRs 90%-ile for the different databases (Table 40, 41, 42 of ECETOC, 2003). Five relevant ACRs have been considered for the estimation of the NOEC for fish long-term toxicity. Table 40 and 41 of the ECETOC (2003) document contain one ACR for all freshwater species and one ACR for all freshwater fish, either derived based on the geometric mean of all data or based on the individual species. The last ACR which was considered distinguishes the mode of action (Table 42 of ECETOC, 2003). DPTA has been identified as a narcotic amine (acute aquatic toxicity classification of OASIS). The ACR (90%-ile) for narcotic substances is 11.5, which is similar to the factor of 10 for the relative species sensitivity of the REACH Guidance Document R.7b chapter R.7.8.5.3 (see following section). All five derived NOECs of this ACR approach by ECETOC are expected to be greater than 1 mg/L.

 

Relative species sensitivity:

According to the REACH guidance document R.7b chapter R.7.8.5.3, there are no further requirements for fish testing, if there is compelling evidence (e.g. using data generated with QSAR models) to suggest that the resulting fish value is likely to be at least a factor of about 10 less sensitive than invertebrates.

In case of DPTA, long-term data are available for aquatic invertebrates and algae(invertebrates:D. magna, 21-d NOEC = 5.6 mg/L, nominal, unbuffered, read-across data from DETA (CAS 111-40-0); algae: D. subspicatus, 72-h ErC10 = 294.3 mg/L, nominal, buffered), but not for fish.

Regarding acute toxicity, invertebrates turned out to be the most sensitive aquatic organism with a 48-h EC50 of 37.4 mg/L (D. magna, nominal, unbuffered). Algae have a lower sensitivity towards DPTA (72-h ErC50 = 1494.5 mg/L, nominal unbuffered). The 72-h LC50 for fish is >500 mg/L under neutralized test conditions. The resulting factor between invertebrates and fish is greater than 13 (factor = 13.4).

Considering the possibility for the prediction of relative species sensitivities according to the REACH Guidance Document R.7b, chapter R.7.8.5.3, further testing on fish would not contribute to improve the current knowledge of the substance and/or its associated risk when released to the aquatic compartment.

 

QSAR data:

To support the approach of relative species sensitivity, acute and chronic toxicity effect values were calculated using the ECOSAR v1.11 model implemented in EPISuite v4.11. The substance is within the applicability domain of the estimation model, applying to all calculations performed for DPTA with ECOSAR. The model categorizes DPTA as an aliphatic amine within its aquatic toxicity scheme.

Considering acute toxicity, the predicted value for fish is a 96-h LC50 of 2959 mg/L. The model calculated a 48-h LC50 of 245 mg/L for daphnids. The 96‑h EC50 for algae was calculated to be 416.5 mg/L. The effect value for fish is in accordance with the available experimental results with pH-adjustment.Considering the effect values for daphnids the toxicity of DPTA is underestimated by the model; in case of algae the model overestimates the toxicity of DPTA.However, the resulting relative species sensitivity factor between the acute toxicity of fish and aquatic invertebrates is about 10 (factor = 12.1) for DPTA with fish being less sensitive than the other two trophic levels.

Furthermore, chronic values (ChV) were estimated using ECOSAR v1.11. The calculated value indicates no concern for long-term toxicity to fish (ChV = 526 mg/L). Due to the limited number of chemicals in the training set (n ≤ 5), the uncertainty of the estimate has to be regarded as high, although the substance is within the model’s applicability domain. However, the ChV is higher than the ChV for aquatic invertebrates by a factor of 38 for Daphnids (ChV = 14 mg/L) and for Green Algae by a factor of 5 (ChV = 106 mg/L).

 

Environmental risk

The Registrant has performed the exposure assessment and the risk characterisation for DPTA. The exposure assessment covers exposure scenarios for the environment from manufacturing of the substance to the use by professionals. Based on the calculated PECs and the derived PNECs, no risk was identified for the environment as all highest risk-characterisation ratios (RCR) were identified to be <1. Therefore, it can be concluded that the chemical safety assessment of DPTA does not trigger the need to investigate further the effects on fish according to Annex I of Regulation (EC) No 1907/2006.

 

In Annex IX of Regulation (EC) No 1907/2006, it is laid down that chronic tests shall be proposed by the registrant if the chemical safety assessment indicates the need to investigate further the effects on fish. According to Annex I of this regulation, the chemical safety assessment triggers further action when the substance or the preparation meets the criteria for classification as dangerous according to Directive 67/548/EEC or Directive 1999/45/EC or CLP-Regulation (EC) No 1272/2008 or is assessed to be a PBT or vPvB. The hazard assessment of the substance reveals neither a need to classify the substance as hazardous to the environment, nor is it a PBT or vPvB substance, nor are there any further indications that the substance may be hazardous to the environment. Therefore, and for reasons of animal welfare, a chronic test in fish is not provided.

 

Overall conclusion on long-term toxicity testing on fish

1.       Experimental acute toxicity data are available for all three trophic levels (fish, aquatic invertebrates and algae).

o  Fish:              72-h LC50 > 500 mg/L (nom., pH-adjusted; BASF AG, 1979)

o  Aq. inv.:       48-h EC50 = 37.4 mg/L (nom., not pH-adjusted; BASF AG, 1989)

o  Algae:           72-h ErC50 = 1494.5 mg/L (nom., pH-adjusted; BASF AG, 1989)

2.       Experimental long-term toxicity data are available for aquatic invertebrates and algae:

o  Aq. inv.:      21-d NOEC = 5.6 mg/L (nom., not pH-adjusted; Akzo, 1992)

o  Algae:          72-h ErC10 = 294.3 mg/L (nom., pH-adjusted; BASF AG, 1989)

3.       In addition to the experimental data, ECOSAR v1.11 was used to estimate acute and chronic effect values for all three trophic levels. The relations between the three trophic levels are in accordance with the experimental

data.

o  Fish:             96-h LC50 = 2959.3 mg/L;ChV = 526.2 mg/L

o  Daphnids:   48-h LC50 = 244.6 mg/L;   ChV = 14.1 mg/L

o  Algae:          96-h EC50 = 416.5 mg/L ; ChV = 106.2 mg/L

4.       According to a weight-of-evidence approach, it can be concluded that fish is not the most sensitive trophic level. This approach is based mainly on the following information sources:

o  Acute-to-chronic ratio by ECETOC (2003)

o  QSAR data (ECOSAR v1.11)

o  Relative species sensitivity (REACH Guidance R.7b, R.7.8.5.3)

5.       Acute-to-chronic ratio (ACR; ECETOC, 2003):
The NOEC is expected to be > 1 mg/L based on five different databases (all freshwater species, all freshwater fish, all freshwater species with individual species, narcotic mode of action).

6.       QSAR data on acute and chronic toxicity for all three trophic levels shows that

o  Fish is the least sensitive trophic level (acute and chronic).

o  The NOEC is estimated to be greater than 1 mg/L. This value is in accordance with the ACR method.

7.       Relative species sensitivity:

o  Based on the available experimental acute toxicity data, the factor between the most sensitive species (aq. inv., EC50 = 22 mg/L) and fish (LC50 > 500 mg/L) is 13.4. This value is > 10 as stated in section R.7.8.5.3 of the REACH Guidance Document R.7b.

o  The relative species sensitivity method was also applied to the QSAR data. The factor based on acute toxicity data for fish to daphnids is 12.1 and to algae 7.1. With respect to algae, the factor is close to but not greater than 10. However, it should be noted that there is a deviation between the experimental and estimated effect values.
Chronic data were not considered further as the database for the chronic models is small inducing a lower soundness of the data.

8.       Long-term toxicity testing is not triggered by the results of the EA/RC. The risk-characterisation ratios (RCR) do not indicate a risk for the environment as all considered exposure scenarios resulted in RCR’s of < 1.

9.       Based on the weight-of-evidence approach, it can be concluded that fish is the least sensitive trophic level. Reliable and valid long-term toxicity data are available for the more sensitive trophic levels aquatic invertebrates

and algae. Therefore, further long-term toxicity testing on fish would not improve the current knowledge of DPTA and/or its associated risk when released to the aquatic compartment.

10.       In addition, DPTA is not a PBT nor a vPvB substance.

11.       Further, it should be taken into consideration that DPTA is not officially classified and is also not to be classified as acutely or chronically hazardous to the environment according to CLP.