1-(C12-C18 even numbered, C18 unsaturated)alkyl-1,4,5,6-tetrahydropyrimidin-2-aminium acetate and{[3-((C12-C18 even numbered, C18 unsaturated)alkylamino)propyl]amino}(imino)methanaminium acetate and[(3-{[ammonio(imino)methyl]amino}propyl)(C12-C18 even numbered, C18 unsaturated)alkylamino](imino)methanaminium diacetate

Endpoint summary

Additional information

GENERAL REMARKS

Issues in Biodegradation testing of the registration substance

1. Following the ECHA decision in 2017 two new biodegradation tests (OECD 301D) with cold material of Lonzabac GA, the registered substance, have been initiated. These tests showed toxicity against microorganisms even at the lowest tested concentrations (2 and 1.6 mg/L). This toxicity masks any metabolization of the substance in the tests. Also the extension of the testing period up to 42 d did not brought gave accpetable results.
2. This means that 14C test item would be the test material of choice. In its decision letter dated 2017 -12 - 08 also ECHA proposed testing with radio labelled material and further, to label the Guanidine site. However, several laboratories specialized in radio labelling synthesis provided proposals for the C1 position of the alkyl chain(s), but no proposal was received for the Guianidine site. Other laboratiries rejected the requests for labelling the substance at all.
3. Since radio labelling and subsequent testing with alkyl-*14C at position 1 material would only show cleavage of the alkyl chain from the rest of the molecules, this approach would not let to conclude on the biodegradation of the guanidium part.
4. In conclusion, the preparation of a representative 14*C material is not feasible, and cold material had to be used for the simulation tests. This poses again a considerable analytical challenge at very low concentration. The two newly generated guideline conform tests for ready biodegradation proved this. On the other hand, results from similar mono-constituent 14C substances and QSAR predictions can be reasonably used for read-across.

 

Read across substances

The registration substance has structural elements like long-chain ammonium and alkyl guanidinium salts. Such structural elements are present in long-chain primary alkyl amines and in guanidinium salts. In the following read-across substances are listed which are all REACH registered and where the substance data can be found on the Dissemination site of ECHA ( http://echa.europa.eu/information-on-chemicals) or at the EU ESIS site ( http://esis.jrc.ec.europa.eu):

·        Gudanidinium nitrate, CAS No, 506 -93 -4

·        Hexadecanamine, CAS No. 143 -27 -1

·        Cocoylamines (C12 -14 Primary alkyl amines), CAS No. 61788 -46 -3

·        C20 -22 alkyl trimethyl ammonium chloride, CAS No. 68607-24-9

 

BIODEGRADATION IN WATER: SCREENING TESTS

The registration substance is toxic to microorganisms and the required minimum test concentration of 1.6 mg/L in a test on ready biodegradation is still too high to allow conditions which are not influencing the viability of the inoculum. As it is not feasible to prepare 14C material of the registration substance (see above) a test at lower concentration could not be performed. Instead read-across is used to justify the conclusion that the registration substance is readily biodegradable:

·        14C-C22 alkyl trimethyl ammonium chloride (see IUCLID Chapter 5.2.1):

OECD 301 B CO2 Evolution test, 0.2 mg/L test conc.: 80% 14CO2 formation after 28d

·        C12 -14 alkyl amines (see IUCLID Chapter 5.2.1):

OECD 301B CO2 Evolution test, 13 mg/L test conc. : >60% CO2 formation after 29d, readily biodegradable

·        Guanidinium nitrate (see ESIS web, CAS 506 -93 -4)

14C Guanidinium nitrate (no concentration given) was incubated with industrial sewage as inoculum and showed 68% 14CO2 formation after 1.3 days.

CONCLUSION

Based on the available facts (see above), it can be concluded that the registration substance is likely to be readily biodegrable if the concentration of the registration substance is low enough to ensure the viability of the inoculum.

 

BIODEGRADATION IN WATER & SEDIMENT

SEWAGE TREATMENT PLANT SIMULATION TEST

An OECD 303A STP Simulation test is carried out with cold registration substance. This is a considerable analytical challenge as low test concentration is warranted due to the high toxicity for microoganisms. For the time being read-across is used (see IUCLID Chapter 5.2.2):

·        C20 -22 alkyl trimethyl ammonium chloride (see IUCLID Chapter 5.2.2)

OECD 303 A: Mean elimination: 99%, mean biodegradation: 92.2% (6.9% sorbed to sludge, 1% to effluent)

 

·        Cocoylamines (C12 -14 Primary alkyl amines, see IUCLID Chapter 5.2.2)

OECD 303A: Mean elimination: 99.8%, mean biodegradation: not measured

 

SIMULATION TEST ON BIODEGRADATION IN SEDIMENT

It is reasonable to use the DT50 of the soil biodegradation simulation test for sediment as well (see REACH Guidance) and therefore no OECD 308 Sediment simulation test is warranted.

OECD 307: highest DT50 soil is 45.5 d at 12 deg C

 

CONCLUSION FOR THE BIODEGRADATION IN WATER & SEDIMENT

STP

The results from the OECD303A with C20 -22 ATQ is used as worst case for the registration substance resulting in 92.% biodegradation, 6.9% sorption to sewage sludge and 1% discharge in effluent.

SEDIMENT

The DT50 of 45.5 d from an OECD 307 soil study with C20 -22 alkyl trimethyl ammonium chloride is used a worst case for the registration substance.

 

BIODEGRADATION IN SOIL

For a Soil biodegradation simulation test according OECD 307 14C material is mandatory to achieve reliable results. As mentioned before the registration substance is a multi-constituent and the synthesis of a representative 14C material not feasible. Therefore read-across is the only way to conclude on soil biodegradation:

·        14C-C22 alkyl trimethyl ammonium chloride (see IUCLID Chapter 5.2.3)

OECD 307: highest DT50 is 45.5 d at env. temperature 12 deg C is used in exposure assessment of the registration substance

 

·        14C-1 -Hexadecanamine (see IUCLDI Chapter 5.2.3)

OECD 307: highest DT50 is 17 d at env. temperature 12 deg C

 

CONCLUSION FOR THE BIODEGRADATION IN SOIL

Both read-across substances show rapid degradation in soil. The worst case result from the OECD 307 carried out with 14C-C22 alkyl trimethylammonium chloride which is DT50 45.4 d at 12 deg C is used in exposure assessment of the registration substance.