2-dibutylaminoethanol

Long-term toxicity to fish

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.

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 algae.

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

The adaptation of the information requirements is justified following a weight-of-evidence approach including the following methods:

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

·        Information on general trends of the toxicity of aliphatic amines

 

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 2-dibutylaminoethanol, long-term data are available for aquatic invertebrates and algae(D. magna, 21-d NOEC = 4.4 mg/L;Rh. subcapitata, 72-h NOEC = 3.2 mg/L, 72-h ErC10 = 6.9 mg/L), but not for fish.

Regarding acute toxicity, algae turned out to be the most sensitive aquatic organism with a 72-h EC50 of 22 mg/L (not pH-adjusted). Aquatic invertebrates have a lower sensitivity towards DBEA (pH-adjusted: 48-h EC50 = 74 mg/L, Danish EPA, 2000; not pH-adjusted: 48-h EC50 > 108 mg/L, NITE, 2004b). The LC50 for fish is 224 mg/Lafor the test with pH-adjustment (96-h LC50 > 100 mg/L to < 500 mg/L). The resulting factor between algae and fish is greater than 10 (factor = 10.2).

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.

 

General trends on toxicity of aliphatic amines

Descriptions of the toxicity of aliphatic amines can be found in the environmental toxicity profile of the aliphatic amines category described in the definition of the chemical categories of the Toxic Substances Control Act (TSCA) New Chemical Program (August, 2010; https://www.epa.gov/sites/production/files/2014-10/documents/ncp_chemical_categories_august_2010_version_0.pdf) and the description contained in the OECD QSAR Toolbox.

According to the descriptions it can be said that small aliphatic amines like 2-dibutylaminoethanol are more toxic to algae than fish and invertebrates. This is accordance with the experimental (and estimated) toxicity data for DBEA.

Another trend described by TSCA and the OECD QSAR Toolbox is that small aliphatic amines are more toxic to fish and invertebrates when they are unionized than when ionized. In contrast, toxicity to algae seems to be unaffected by ionization. Based on an experimentally determined pKa of 10.3 for DBEA (BASF SE, 2013; report no. 11L00536), DBEA is predominately ionized under environmentally relevant conditions.

It can be concluded that the trends for aliphatic amines are in accordance with the analysis of the relative species sensitivity with regard to the relations between fish and invertebrates to algae.

 

Environmental risk

The Registrant has performed the exposure assessment and the risk characterisation for DBEA, which will be included together with the next update of the dossier. The exposure assessment covers 21 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. The highest risk-characterisation ratios (RCR) were identified to be <0.2 for the exposure scenario “Use in industrial chemical processes” and the compartments freshwater, freshwater sediment, marine water and marine sediment.

Therefore, it can be concluded that the chemical safety assessment of DBEA 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).

-      Fish:         96-h LC50 = 224 mg/L (nom., pH-adjusted; BASF AG, 1987, report no. 10F0432/865014)

-      Aq. inv.:    48-h EC50 = 74 mg/L (meas., pH-adjusted; Danish EPA, 2003)

-      Algae:       72-h ErC50 = 22 mg/L (meas., not pH-adjusted; NITE, 2004d)

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

-      Aq. inv.:    21-d NOE = 4.4 mg/L (meas., pH-adjusted; NITE, 2004c)

-      Algae:       72-h NOEC = 3.2 mg/L,
                  72-h ErC10 = 6.9 mg/L (meas., not pH-adjusted; NITE, 2004d)

3.    Relative species sensitivity:

-      Based on the available experimental acute toxicity data, the factor between the least sensitive species (algae, ErC50 = 22 mg/L) and fish (LC50 = 224 mg/L) is 10.2. This value is > 10 as stated in section R.7.8.5.3 of the REACH Guidance Document R.7b.

-      The relative species sensitivity method was also applied to the QSAR data. The factor based on acute toxicity data for fish to daphnids is 8.5 and to algae 10. With respect to daphnids, 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.

4.    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 (RCR < 1).

5.    Based on the available ecotox data, 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 DBEA and/or its associated risk when released to the aquatic compartment.

6.  In addition, 2-dibutylaminoethanol is not a PBT nor a vPvB substance.

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

 

References

-      BASF AG (1987). Report on the study of the acute toxicity of dibutylethanolamin to golden orfe (Leuciscus idusL., golden variety). Unpublished. Testing laboratory: BASF AG, Department of Toxicology, Ludwigshafen, Germany.Report no.: 10F0432/865014. Report date: 1987-09-11.

-      BASF AG (1993). Bestimmung des Verteilungskoeffizienten log Pow der Prüfsubstanz in 1-Octanol/Wasser bei 25 °C. Unpublished.Testing laboratory: BASF AG, ZSZ/PA - M 325 . Report no. 93P00886.07. Report date: 1993-02-18.

-      BASF SE (2011). LC50 recalculation in the fish test. Unpublished. Testing laboratory: BASF SE, Department for Product Safety, Ludwigshafen, Germany. Report date: 2011-02-15.

-      BASF SE (2013). Determination of pKa for CAS 102-81-8. Testing laboratory: BASF SE, Competence Center Analytics, Germany. Report no. 11L00536. Report date: 2013-08-21.

-      BASF SE (2014). Alga, Growth Inhibition Test (OECD 201, EEC, ISO): NITE (2004): 2-(Dibutylamino)ethanol, OECD 201. Unpublished. Testing laboratory: ECT Oekotoxikologie GmbH, Flörsheim, Germany. Report date: 2014-02-25.

-      Danish Environmental Protection Agency (2000). Immobilization test of selected organic amines with the crustacean Daphnia magna. Danish EPA, Copenhagen, Denmark, 52 pp. Testing laboratory: Institute for the Water Environment (VKI), Horsholm, Denmark. Report no. VKI Study report 11531; lab no. 81119/247. Report date: 2000-03-27.

-      ECHA (2017). Guidance on Information Requirements and Chemical Safety Assessment: Chapter R.7b: Endpoint specific guidance. Version 4.0, June 2017.

-      Ingerslev et al. (2001). Cited in ECHA (2017).

-      NITE (2001). 2-(dibutylamino)ethanol: Bioaccumulation in common carp, OECD 305C. Unpublished. Testing laboratory: NITE Japan. Report no. A010219. Report date: 2001-12-07.

-      NITE (2004a). 2-(dibutylamino)ethanol:Oryzias latipes, OECD 203. Unpublished. Testing laboratory: NITE Japan. Report date: 2004-04-21.

-      NITE (2004b). 2-(dibutylamino)ethanol:Daphnia magna, OECD 202. Unpublished. Testing laboratory: NITE Japan. Report date: 2004-04-21.

-      NITE (2004c). 2-(dibutylamino)ethanol:Daphnia magna, OECD 211. Unpublished. Testing laboratory: NITE Japan. Report date: 2004-04-21.

-      NITE (2004d). 2-(dibutylamino)ethanol:Pseudokirchneriella subcapitata, OECD 201. Unpublished. Testing laboratory: NITE Japan. Report date: 2004-04-21.

-      NITE (2011). Information on Environmental Toxicity. Bibliographic source: National Institute of Technology and Evaluation (NITE), Japan. Fiscal year of report: 2003; available at:http://www.safe.nite.go.jp/english/db.html. Testing laboratory: MOE, Japan. Report date: 2011-08-24