Quaternary ammonium compounds, bis(hydrogenated tallow alkyl)dimethyl, acetates

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

6.2 µg/L

Assessment factor:

10

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

0.002 mg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.62 µg/L

Assessment factor:

100

Extrapolation method:

assessment factor

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

0.21 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

55 mg/kg sediment dw

Assessment factor:

10

Extrapolation method:

assessment factor

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

11 mg/kg sediment dw

Assessment factor:

50

Extrapolation method:

assessment factor

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

7.3 mg/kg soil dw

Assessment factor:

50

Extrapolation method:

assessment factor

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Additional information

No aquatic toxicity studies with the test substance are available. Therefore, studies with DHTDMAC (CAS 61789-80-8), DMDTC (CAS 68783-78-8) and DODMAC (CAS 107-64-2) were used as read across to fulfil the data gap for the test substance. The primary component of all substances provide complete coverage of 68334-33-8.  68334-33-8 shares high structural similarity with 61789-80-8, 68783-78-8, 107-64-2, and 112-02-7. As 68334-33-8 is a UVCB its components encapsulate the other substances except for the counter ion (Cl-). In solution, the counter ions will dissociate from the parent structures.  Therefore, we are comparing substances of equivalent nature. CAS 107-64-2 represents the C18 boundary of the 61789-80-8. Ignoring the salt component CAS 61789-80-8 is equivalent to CAS 68334-33-8. 68783-78-8 is a worst case of both 68334-33-8 and 61789-80-8 since it is unsaturated and the SP2 carbon-carbon bonds are of higher reactivity and a more likely site of metabolic activation. The primary component of CAS 112-02-7 is a substructure of all the other substances. Additional documentation, provided within the IUCLID Assessment Reports section, supports the read-across approach.

A European Risk Assessment Report has been issued in 2002 by German Authorities for read-across substances. Some of the previously defined PNECs were revisited according to this core document but all the PNECs remain very similar to those presented in the EU RAR.

Conclusion on classification

Based on read-across to analogous substances, the test substance is considered as very toxic for the aquatic compartment based on the generated aquatic toxicity package with a 48-hour EC50 in daphnia of 0.16 mg/L and a 5-day NOEC in algae of 0.062 mg/L, and the fact that it is not readily biodegradable, the test substance is classified as Cat 1 (H400: Very toxic to aquatic life) for acute aquatic toxicity and as Cat 1 (H410: Very toxic to aquatic life with long lasting effects for chronic aquatic toxicity according to EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.

In accordance with article 10 of the CLP Regulation (EC) No 1272/2008, if an M-factor is not yet given in Part 3 of Annex VI to the CLP Regulation, an M-factor should be determined and a scientific justification provided, when classifying substances for Acute Category 1 or Chronic Category 1. For this substance, adequate acute aquatic data are available in fish, aquatic invertebrates, and algae. An Acute M-Factor is based on the lowest reported effects in the most sensitive species fish, aquatic invertebrate and algae. Therefore, the M factor is 1 based on the 96-hr EC/LC50 of 0.62 mg/L in fish, the 48-hr EC/LC50 of 0.16 mg/L in aquatic invertebrate and the 96 h EC/LC50 of 0.36 mg/L in algae.

 

The current data support an M-factor of 1. However, the substance was tested in river water which contains suspended solids to which very adsorptive substances like cationic amines will bind. Therefore, exposure to nominal concentration of cationic amine is reduced (adsorbed material is not bioavailable). A conservative 90% of the nominal concentration was considered to adsorb on suspended solids. Only exposure to 10% of the nominal concentration was considered and therefore an additional safety factor was applied, resulting in a chronic M-factor of 10.