2,2'-iminodiethanol

Long-term toxicity to fish

Description of key information

No data available; however, long-term effects on fish are not expected.

Additional information

Long-term toxicity testing on fish (Annex IX, Section 9.1.6.1.)

Description of available data

 

Ecotoxicity

Short-term toxicity data are available for all three trophic levels (fish, aquatic invertebrates and algae).

In case of fish, the key study by the Petroleum Technology Alliance Canada (PTAC), 2006 was performed according to Environment Canada method, Biological Test Method: Acute Lethality Test, EPS 1/RM/9 (EC 1990/1996) using rainbow trout Oncorhynchus mykiss as test species. Exposure conditions were static and test concentrations were analytically verified as stable. The 96-h LC50 was determined to be 460 mg/L (nominal). In a further study with fathead minnow (Pimephales promelas) this result was supported by an even higher 96-h LC50 of 1460 mg/L (Mayes et al., 1983).

Regarding aquatic invertebrates, a static acute immobilization study performed according to ASTM Standard E729-80 with Ceriodaphnia dubia as test organism was selected as key study (Cowgill et al., 1985). The 48-h EC50 was determined to be 30.1 mg/L. The lowest reliable value for acute toxicity to Daphnia magna was reported from a static test according to US EPA Guideline 600/3-75-009 (LeBlanc, 1980). Based on nominal concentrations, the 48-h EC50 was 55 mg/l. However, since measured pH values ranged from 7.4 to 9.4, alkaline pH effects might have contributed to the observed mortality. In addition, the acute toxicity of diethanolamine to D. magna was investigated in a 48-hour static test according to OECD TG 202. Based on nominal concentrations, the 48-h EC50 was 171 mg/l (Zurita et al., 2005). Furthermore, the effect of diethanolamine on Hyalella azteca was studied according to an Environment Canada method (PTAC, 2006). The 96-h LC50 was determined to be 344 mg/L (nominal, analytically verified).

Regarding the acute toxicity of diethanolamine to algae, data of different studies and screening tests are available covering the freshwater species Pseudokirchneriella subcapitata, Desmodesmus subspicatus, Ankistrodesmus bibraianus as well as the marine species Phaeodactylum tricornutum. The most sensitive result was obtained in a GLP study following the US EPA algal assay bottle test 600/9-78-018 (1978) and using the green algae P. subcapitata (formerly Selenastrum capricornutum) (DOW Chemical, 1982). Test 1 and test 2 were re-evaluated by using ToxRat Professional v2.10 (BASF SE, 2015). The 72-h ErC50 was determined to be 9.5 mg/L (test 1) and 19 mg/L (test 2). The effect of pH-adjusted and non-adjusted test solutions with diethanolamine was examined in screening studies with A. bibraianus and D. subspicatus in 72-hour static tests following the German Industrial Standard DIN 38412, part 9 (BASF AG, 1992/1444/60, Rep. no 92/1444/60). These screening tests were selected as supporting studies. The measured data of the screening tests were re-evaluated with ToxRat v2.10 (BASF SE, 2015). For A. bibraianus the 72-h ErC50 under non-adjusted conditions was determined to be 57.5 mg/L. The ErC50 for pH-adjusted test solutions could not be calculated due to the limited number of replicates. However, as the highest concentration tested was 100 mg/L and the chronic value for pH-adjusted test solutions is already calculated to be > 100 mg/L (ErC10, pH-adjusted: 123.9), the ErC50 under pH-adjusted conditions is concluded to be clearly >100 mg/L. The respective 72-h ErC50 values for D. subspicatus were 14.9 mg/l (pH-adjusted) and 107.3 mg/l in non-adjusted test solutions. Finally, in a supporting study by Libralato et al. (2010) marine algae were tested according to ISO 10253. The test species was P. tricornutum. The concentration of the test item was analytically verified in the stock solution. After 72 h of exposure an EC50 of 86.96 mg/L was determined.

Based on the results mentioned above, it is reasonable to conclude that diethanolamine is with high probability acutely not harmful to fish (96-h LC50 > 100 mg/L). However, diethanolamine has to be considered acutely harmful to aquatic invertebrates (lowest 48-h EC50 >10 and ≤ 100 mg/L) and acutely toxic to algae (lowest 72-h EC50 >1 and ≤ 10 mg/L).

 

Long-term toxicity data are available for aquatic invertebrates and algae. With regard to aquatic invertebrates, long-term effects of diethanolamine were investigated in a semi-static reproduction test with Daphnia magna according to the draft EEC guideline XI/681/86 "Prolonged toxicity study with D. magna: Effects on reproduction" (BASF AG, 1992) following GLP and with analytically verified test concentrations. The effect values were recalculated using ToxRat Professional v2.10 (BASF SE, 2016) and the EC10 after 21 days of exposure based on reproduction was determined to be 1.05 mg/L (nominal). The long-term effects of diethanolamine on green algae were examined in studies with P. subcapitata, A. bibraianus and D. subspicatus. In a GLP key study following the US EPA algal assay bottle test 600/9-78-018 (1978) and using the green algae P. subcapitata (formerly S. capricornutum) the 72-h ErC10 was determined to be 1.4 mg/L (test 1) and 1.1 mg/L (test 2) (DOW Chemical, 1982). These results were re-evaluated by using ToxRat Professional v2.10 (BASF SE, 2015). In the screening tests mentioned above (BASF AG, 1992, Rep. no 92/1444/60) the 72-h ErC10 under non-adjusted conditions was determined to be 30.1 mg/L for A. bibraianus. The 72-h ErC10 for pH-adjusted test solutions was calculated to be 123.9. The respective 72-h ErC10 values for D. subspicatus were 2.4 mg/L (pH-adjusted) and 85.7 mg/L in non-adjusted test solutions. All results were re-evaluated with ToxRat v2.10 (BASF SE, 2015).

Based on these results, diethanolamine is not expected to be chronically hazardous to aquatic invertebrates and algae (EC10 > 1 mg/l).

 

 

Classification

With regard to CLP, diethanolamine is not to be classified as acutely or chronically hazardous to the environment based on the available acute and chronic data. In accordance with Regulation (EC) No 1272/2008, Annex VI Table 3.2, the substance is not officially classified with regard to environmental hazards.

The substance is not to be classified as acutely hazardous to the aquatic environment, since the lowest acute effect value is > 1 mg/L (algae: EC50 = 9.5 mg/L).

Chronic toxicity data are available for daphnids (21-d EC10 > 1 mg/L) and algae (72-h EC10 > 1 mg/L). According to the criteria outlined in Table 4.1.0(b)(ii) (Commission Regulation (EU) No 286/2011 amending Regulation (EC) No 1272/2008 for rapidly degradable substances), the substance is not to be classified as chronically hazardous to the aquatic environment.

Fish is the trophic level which is not covered by chronic data. Therefore, classification is based on the respective acute data; for fish, the 96-h LC50 was determined to be 460 mg/L. The substance is readily biodegradable (see IUCLID Ch. 5.2.1); the log Kow is < 4 (log Kow = -2.46; see IUCLID Ch. 4.7). According to the criteria outlined in Table 4.1.0(b) (iii) (Commission Regulation (EU) No 286/2011 amending Regulation (EC) No 1272/2008), the substance is not to be classified as chronically hazardous to the aquatic environment.

 

 

Long-term toxicity to fish

For reasons of animal welfare and in accordance with the REACH Guidance R.7b, R.7.8.5.3, the information requirements for fish of Annex IX can be adapted by omitting the long-term toxicity test with fish according to Annex I and IX of Regulation (EC) No 1907/2006. The applied method is the relative species sensitivity.  

In case of diethanolamine (CAS 111-42-2), long-term toxicity data are available for aquatic invertebrates and algae, but not for fish. Regarding acute toxicity, algae have a higher sensitivity than aquatic invertebrates (C. dubia, 48-h EC50 = 30.1 mg/L) or fish (O. mykiss, 96-h LC50 = 460 mg/L). For algae, the 72-h ErC50 is 9.5 mg/L (P. subcapitata). The resulting factor between algae and fish is greater than 10 (factor = 48.4).

The available long-term toxicity data for aquatic invertebrates and algae show that both trophic levels are similarly sensitive. In addition, the data lead to the conclusion that long-term effects are not to be expected. No effects were observed for aquatic invertebrates and algae up 1 mg/L.

 

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.

 

 

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).
   
   
   
   1. Fish: 96-h LC50 = 460 mg/L (meas., not pH-adjusted)
   
   
   2. inv.: 48-h EC50 = 30.1 mg/L (nom., not pH-adjusted)
   
   
   3. Algae: 72-h ErC50 = 9.5 mg/L (nom., not pH-adjusted)
   
   
   
   

2. Experimental long-term toxicity data are available for aquatic invertebrates and algae:
   
   
   
   1. inv.: 21-d EC10 = 1.05 mg/L (meas., not pH-adjusted)
   
   
   2. Algae: 72-h ErC10 = 1.1 mg/L (nom., not pH-adjusted)
   
   
   
   

3. Relative species sensitivity: Based on the available experimental acute toxicity data, the factor between the most sensitive species (algae, EC50 = 9.5 mg/L) and fish (LC50 = 460 mg/L) is 48.4. This value is > 10 as stated in section R.7.8.5.3 of the REACH Guidance Document R.7b.
   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 diethanolamine and/or its associated risk when released to the aquatic compartment.


4. In addition, diethanolamine is not a PBT nor a vPvB substance.


5. Further, it should be taken into consideration that diethanolamine is not officially classified with regard to environmental hazards and is also not to be classified as acutely or chronically hazardous to the environment according to CLP.


6. Waiver for the endpoint “Long-term toxicity testing on fish” (Annex IX, Section 9.1.6. of the REACH Regulation): In Annex IX, Section 9.1.6, Column 2 of Regulation (EC) No 1907/2006, it is laid down that long-term toxicity testing on fish 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 CLP-Regulation (EC) No 1272/2008 and its second adaptation 286/2011 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 (ECHA, June 2017, v4.0), 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. In Annex XI, Section 3, it is laid down that testing in accordance with Annex IX and Annex X may be omitted, based on the exposure scenario(s) developed in the Chemical Safety Report (“Substance-Tailored Exposure-Driven Testing”). In accordance with Annex XI Section 3, it can be demonstrated in the risk assessment that the manufacture and the use of the substance do not pose an unacceptable risk for all environmental compartments as the risk characterization ratios (RCRs) of the chemical safety assessment are below 1 for all compartments (see Chemical Safety Report Ch. 10). 

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