Quaternary ammonium compounds, bis(C16-18 and C18-unsatd. alkyl)dimethyl, chlorides

Short-term toxicity to aquatic invertebrates

Description of key information

Toxicity figure based on river water testing.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

3.1 mg/L

Additional information

Read across for DTDMAC from structurally similar Quats DHTDMAC/DODMAC can be applied and the corresponding effect data form DHTDMAC/DODMAC used for DTDMAC as well.

In the Endpoint Summary Aquatic toxicity (IUCLID Chapter 6.1) an Overview table with the available acute invertebrate tests is given. From the EU Risk Assessment DODMAC (EU, 2002) the following discussion on acute invertebrate toxicity is available:

Acute toxicity to Invertebrates

The influence of the test medium on the acute toxicity of DODMAC toDaphnia magnawas investigated by Lewis & Wee, 1983. Surface water was collected from a North American river which received municipal wastewater effluent (White River,Indiana). The quality of the river water was: pH = 8.4 - 8.6, total hardness = 345 - 363 mg/l CaCO3, 3-5 mg/l suspended solids, < 25 µg/l MBAS, 2 µg/l DBAS. As reference laboratory reconstituted water was used: pH = 6.6 - 7.9, total hardness = 131 -163 mg/l CaCO3, no suspended solids, < 25 µg/l MBAS, < 1 µg/l DBAS. In semistatic tests the LC50-values were 3.1 mg/l in river water and 0.16 mg/l in laboratory water after 48 hours (measured conc.).

Daphnia magnawas also tested in a 21d-static renewal test with the same river water as quali­fied above (Lewis & Wee, 1983). Referring to the reproduction rate and mean length of the daphnids a NOEC of 0.38 mg/l DODMAC was derived (measured conc.). Parent mortality was not significantly affected up to 0.76 mg/l.

The acute toxicity of DHTDMAC (no information on purity) toDaphnia magnawas assessed for different reconstituted waters and well water with the same US EPA test method as above (Lewis & Wee, 1983). After 48 hours LC50-values of 0.19 and 0.48 mg/l were derived for the reconstituted waters and the LC50 for well water was 1.06 mg/l (nominal levels of the active ingredient). From the available reference it is not possible to relate the LC50-values to the different qualities of the reconstituted waters, which were given as follows. One water had a pH of 6.5 to 7.3 and a total hardness of 131 - 163 mg/l CaCO3. The other water had a pH of 7.0 to 7.6 and a total hardness of 34 - 40 mg/l CaCO3. (Well water: pH = 7.1 - 7.9, total hard­ness = 315 - 348 mg/l CaCO3.) All waters contained no solids and the surfactants concen­trations were below the detection limit.

The acute data forDaphnia magnashow that the toxicity of DODMAC is very similar to that of DHTDMAC. This conclusion can be supported by the long-term data forCeriodaphnia dubia.