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PBT assessment

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PBT assessment: overall result

PBT status:
the substance is not PBT / vPvB
Justification:

Dimethyl alkyl amine Category

Based on evaluation of the data described, it is concluded here that the members of the DMA (dimethylalkylamine) category

·   are readily biodegradable and therefore clearly do not fulfil the P criterion,

·   are not fulfilling the B (or vB) criterion,

·   are fulfilling the T criterion based on chronic toxicity towards freshwater algae

and therefore are evaluated to be neither PBT nor vPvB substances.

Overall conclusion:

Based on the assessment described in the subsections below, the submission substances of the category of dimethylalkylamines (DMA) are evaluated to be neither PBT nor vPvB.

Evaluation of the Persistence of Impurities of Dimantine (CAS No. 124 -28 -7)

1.      Octadecan-1-ol, CAS No. 112-92-5, EC No. 204-017-6
REACH Registration No.01-2119485907-20-0000
ECHA Information on Chemicals
http://apps.echa.europa.eu/registered/data/dossiers/DISS-9c7e368e-0303-556e-e044-00144f67d249/DISS-9c7e368e-0303-556e-e044-00144f67d249_DISS-9c7e368e-0303-556e-e044-00144f67d249.html

According the above mentioned REACH Information, Octadecan-1-ol is readily biodegradable and has a half-life in rivers of 2d (see PBT Assessment of the substance). Therefore the substance is not P/vP according the Criteria based on Annex XIII of REACH.

2.      Alkyldimethylamines

2.1  Dodecyldimethylamine (C12 DMA), CAS No. 112-18-5, EC No. 203-943-8
REACH Registration No. 01-2119486658-18-0000
ECHA Information on Chemicals

http://apps.echa.europa.eu/registered/data/dossiers/DISS-9d9c85d9-3eb9-4bbe-e044-00144f67d249/DISS-9d9c85d9-3eb9-4bbe-e044-00144f67d249_DISS-9d9c85d9-3eb9-4bbe-e044-00144f67d249.html
According the above mentioned REACH Information, Dodecyldimethylamine is readily biodegradable (see Chapter Biodegradation in water: screening tests). Therefore the substance is not P/vP according the Criteria based on Annex XIII of REACH.

2.2  Dimethyl(tetradecyl)amine (C14 DMA), CAS No. 112-75-4, EC No. 204-002-4

REACH Registration No.01-2119486674-24-0000
ECHA Information on Chemicals

http://apps.echa.europa.eu/registered/data/dossiers/DISS-9d931935-8e1e-4a30-e044-00144f67d249/DISS-9d931935-8e1e-4a30-e044-00144f67d249_DISS-9d931935-8e1e-4a30-e044-00144f67d249.html

According the above mentioned REACH Information, Dimethyl(tetradecyl)amine is readily biodegradable (see Chapter Biodegradation in water: screening tests). Therefore the substance is not P/vP according the Criteria based on Annex XIII of REACH.

2.3  Hexadecyldimethylamine (C16 DMA), CAS No. 112-69-6, EC No. 203-997-2
REACH Registration No.01-2119485394-29-0000
ECHA Information on Chemicals

http://apps.echa.europa.eu/registered/data/dossiers/DISS-9d9b6d14-22cd-4123-e044-00144f67d249/DISS-9d9b6d14-22cd-4123-e044-00144f67d249_DISS-9d9b6d14-22cd-4123-e044-00144f67d249.html

According the above mentioned REACH Information, Hexadecyldimethylamine is readily biodegradable (see Chapter Biodegradation in water: screening tests). Therefore the substance is not P/vP according the Criteria based on Annex XIII of REACH.

2.4  N,N-Dimethylicosylamine (C20 DMA), CAS No. 45275-74-9, EC No. 256-216-2

N,N-Dimethylicosylamine is the C20 homologue of the Alkyldimethylamines but is not part of the C12 to C18 alkyldimethylamine Category registered under REACH. For C20 DMA no information exists at the ECHA Information of Chemicals website. All members of the C12 to C18 DMA category are readily biodegradable. In addition detailed data exist on the metabolism of Diamantine (C18 DMA), CAS No. 124-28-7, EC No. 2014-694-8, REACH Registration No.01-2119486676-20-0000 (http://apps.echa.europa.eu/registered/data/dossiers/DISS-9d88e94d-b51a-0bf6-e044-00144f67d249/DISS-9d88e94d-b51a-0bf6-e044-00144f67d249_DISS-9d88e94d-b51a-0bf6-e044-00144f67d249.html)demonstrating oxidative cleavage of the long-chain C-N bond and subsequent beta oxidation and mineralization of the fatty acid formed. The dimethylammonium compound formed from the C-N cleavage is mineralized as well (see Chapter Mode of degradation in actual use). This metabolic pathway is not limited to tertiary amines but is observed for primary, secondary and quaternary long-chain alkylamines as well (van Ginkel, 1995). Based on this data it can be assumed that C20 DMA is also degraded along this metabolic pattern. But it cannot be simply extrapolated from the C12 to C18 DMA that C20 DMA is readily biodegradable.For C20-22 DMA, CAS No. 93164-85-3, EC No. 296-866-4, REACH Registration No.01-2119486797-14-0000http://apps.echa.europa.eu/registered/data/dossiers/DISS-9fdca675-751d-4afd-e044-00144f67d031/DISS-9fdca675-751d-4afd-e044-00144f67d031_DISS-9fdca675-751d-4afd-e044-00144f67d031.htmlan OECD 301B ready test exists where under the test conditions with 16 mg/L test item ready biodegradability could not be achieved. For primary alkyl amines it is observed that with higher carbon chain length e.g. >= C18 ready biodegradability cannot always be achieved as the biodegradation rate is limited by the dissolution rate of the substance (flattening of the biodegradation curve). On the other hand it is well known that the biodegradability can be enhanced when the test item concentration is lowered. But for analytical reasons this may not always help. Using a 14C labelled test item in an OECD 301B test at a low concentration of e.g. 0.2 mg/L allows measuring reliably the formation of 14CO2. At such low concentration is very reasonable that C20-22 DMA is readily biodegradable as are the lower carbon chain homologues. But unfortunately a test at such low concentration is neither available for C20 DMA nor for C20-22 DMA.

However [14C]-C22 trimethylammonium chloride ([14C]-C22 ATQ) is readily biodegradable at 0.2 mg/L and C22 DMA is its synthetic precursor (see Chapter Biodegradation in water: screening tests of Quaternary ammonium compounds, C20-22-alkyltrimethyl chlorides CAS No. 68607-24-9, EC No. 271-756-9, REACH Registration No.01-2119484817-22-0000,http://apps.echa.europa.eu/registered/data/dossiers/DISS-9fdca675-751d-4afd-e044-00144f67d031/AGGR-16821ee7-6530-49be-be32-cfc14531bf8a_DISS-9fdca675-751d-4afd-e044-00144f67d031.html#section_1.1)

It is important to note that for C20-22 ATQ in OECD 301B tests at 10 mg/L and 5 mg/L 21% respectively 40% biodegradation could be achieved after 28d clearly demonstrating higher biodegradation at the lower concentration of 5 mg/l. But only with [14C]-C22 ATQ at 0.2 mg/L ready biodegradability could be demonstrated (80% biodegradation after 28d).

As mentioned before the quaternary compound is metabolized according the same metabolic pathway as the tertiary C22 DMA which is its precursor. Based on this information it can be concluded that C22 DMA as [14C]-C22 ATQ is readily biodegradable and the shorter chain C20 DMA as well. This means that C12 to C22 DMAs are all readily biodegradable. Therefore the substance C20 DMA is not P/vP according the Criteria based on Annex XIII of REACH.

 

CONCLUSION on vPvB / PBT Properties of Impurities of Dimantine (C18 DMA)
All impurities in C18 DMA (Dimantine) are readily biodegradable and are therefore not P/vP (ECHA. 2014). This means they are also not vPvB and not PBT.
C18 DMA (Dimantine) as already stated in the PBT Assessment of the substance and the impurities included (see before) are not PBT and not vPvB.

  

References

ECHA 2014, Guidance on Information Requirements and Chemical Safety Assessment, Chapter R.11: PBT/vPvB Assessement, Version 2.0, November 2014, ISBN 978-92-9244-760-1, specific reference to pages 34-35

Van Ginkel 1995, Biodegradability of cationic surfactants: Chapter 6 in ‘Biodegradability of Surfactants’, Ed. Karsa, D and Porter, M, Springer, 1995, ISBN 978-94-011-1348-9,http://www.springer.com/us/book/9780751402063

Likely routes of exposure:

An emission characterisation need not be carried out as the submission substance is neither a vPvB nor a PBT substance.