Amines, C36-alkylenedi-

Endpoint summary

Additional information

C36 -alkylenediamines are very poorly soluble in water and also have a strong tendency to adsorb to negatively charged surfaces such as suspended matter and test vessels or organic material (including dissolved organic matter such as humic acids). Many cationic substances in general but long chain amines in particular rank among the most difficult substances to test in environmental toxicology. Standard guideline studies are inappropriate to test substances with such properties and the current REACH Guidance Documents do not provide sufficient guidance concerning bioavailability and exposure assessment for cationic surface-active substances like the C36 -alkylenediamines as these were written with normal hydrophobic chemicals in mind, failing to take into account the lack of bioavailability that occurs in the environment with these substances. C36 -alkylenediamines is considered to be inherently biodegradable and considered to be stable under ecotox testing conditions. The aquatic ecotoxicity tests with C36 -alkylenediamines were, due to the extreme low water solubility, performed using the Water Accommodated Fraction (WAF) approach and effects if observed are presented based on loading and observed dissolved concentration.

 

An overview of the most relevant results is provided in the table.

Method	Results	Results, converted to active ingredient	Remarks	Reference
Acute fish 96h OECD 203	No effects observed LL0 = 100 mg/L LC0 = 275 µg/L	No effects observed   LL0 = 99.9 mg/L LC0 = 275 µg/L	Reliability 1   Loading Geomean measured	Akzonobel, 2012
Acute Daphnia 48h OECD 202			Long term test performed as no effects were anticipated due to the low water solubility
Algae 72h OECD 201	ErC50 = 44.3 µg/L	ErC50 = 44.3 µg/L	Reliability 1 Measured initial	Scheerbaum, D. 2012
Long term toxicity Daphnia 21d OECD 211	No sign. effects observed EL10 = 4.39 mg/L EC10 = ± 12.8 µg/L	No sign. effects observed EL10 = 4.39 mg/L EC10 = ± 12.8 µg/L	All endpoints Reliability 1 Loading Geomean measured	Noack, M. 2012
Algae 72h OECD 201	ErC10 = 11.7 µg/L	ErC10 = 11.7 µg/L	Reliability 1 Measured initial	Scheerbaum, D. 2012

 

Conclusion

Acute toxicity results are available for fish and algae. Long term toxicity results are available for aquatic invertebrates and algae. No significant effects were observed in the acute fish and long term daphnia test during exposure to the water accommodated fraction (WAF) of C36 -alkylenediamines. In the algae test significant effects were observed in the WAF. C36 -alkylenediamines is a strongly sorbing substance which sorbs strongly to algae during the test. According to the OECD guideline 201 (paragraph 40) it is acknowledged that quantification of such substances, particularly when low concentrations are concerned, quantification at the end of the study can be difficult. In such case, if the substance is stable under test conditions, the use of measured initial concentrations is considered acceptable.

For this reason it is considered justified to use the measured initial concentration to base the dose response on and not the mean measured concentration as most of the measured initial test substance concentration is actually either sorbed to algae or in the test solution.