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Ecotoxicological information

Endpoint summary

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Additional information

The information summarized hereafter comes from the european risk assessment report.

The effect values are all nominal values and are not converted to a standard soil of a defined organic carbon content, because this does not seem to be adequate as the bioavailability of Quaternary ammonium compounds, di-C16 -18 (even numbered) - alkyldimethyl, chlorides is not determined by the organic matter content alone but also by other soil parameters e.g. ionic binding. The different test concentrations were prepared at maximum one day before the start of the test and adsorption was rapid.

Toxicity of Quaternary ammonium compounds, di-C16 -18 (even numbered) - alkyldimethyl, chlorides to terrestrial organisms

Species

Endpoint

Effect Conc.

Substance

Reference

Sinapis alba

Triticum aestivum

Linum utisatissimum

14d EC5

14d EC50

14d EC5

14d EC5

1,400 mg/kg

3,540 mg/kg

> 1,000 mg/kg

> 1000 mg/kg

DHTDMAC

Pestemer et al., 1991

Sorghum bicolor

Helianthus annuus

28d EC50

NOEC

28d EC50

NOEC

2,530 mg/kg

1,000 mg/kg

2,930 mg/kg

1,000 mg/kg

DHTDMAC

Windeatt, 1987

Avena sativa

Brassica rapa

14d NOEC

14d NOEC

> 1,000 mg/kg

> 1,000 mg/kg

DHTDMAC

Stanley & Tapp, 1982

Eisenia fetida

14d NOEC

> 1,000 mg/kg

DHTDMAC

Coulson et al., 1989

Lycopersicum escul.

Lactuca sativa

Hordeum vulgare

NOEC

(growth)

> 40 g/kg (dw)

DHTDMAC

Topping & Waters, cited in ECETOC 1993

soil microorganisms

14w NOEC

28d NOEC

> 400 mg/kg

> 365 mg/kg

DHTDMAC

DHTDMAC

Procter & Gamble, 1992

Täuber et al., 1986

The toxicity of Quaternary ammonium compounds, di-C16 -18 (even numbered) - alkyldimethyl, chlorides (75% purity; named DSDMAC in the reference) to plant seedlings was tested by Pestemer et al. (1991) in a loamy sandy soil (1.3% organic carbon, 9.9% clay, 54.3 sand, 35.7 silt). Seedlings with developed cotyledons were exposed for 14 days. Related to fresh weight reduction the most sensitive species was Sinapis alba with an EC5 of 1,400 mg/kg dry weight and an EC50 of 3,540 mg/kg dry weight. For Triticum aestivum and Linum utisatissimum the EC5-values were above 1,000 mg/kg dw. In a germination test Quaternary ammonium compounds, di-C16 -18 (even numbered) - alkyldimethyl, chlorides concentrations up to 3.2 g/L had no inhibiting effect on Lepidium sativum (Pestemer et al. 1991).

In another study (Windeatt, 1987), the influence of Quaternary ammonium compounds, di-C16 -18 (even numbered) - alkyldimethyl, chlorides (76.1% active ingredient = quartenary ammonium) on the emergence of plant seedlings and the early growth stages of Sorghum bicolor and Helianthus annuus were investigated. Potting compost with about 80% sand/gravel and 20% silt/clay including 4% organic matter was used as substrate. The highest test concentration of 10 g active ingredient of Quaternary ammonium compounds, di-C16 -18 (even numbered) - alkyldimethyl, chlorides per kg dry soil had no significant effect on the emergence of seeds after 7 days. After further 21 days the EC50 for fresh weight reduction of the seedlings was 2530 mg/kg for Sorghum bicolor and 2,930 mg/kg for Helianthus annuus (active ingredient in dry soil). 1,000 mg/kg was the highest test concentration with no growth effect. For Phaseolus aureus the 28 d EC50 was > 10 g/kg.

Similar results were reported for Avena sativa and Brassica rapa (Stanley, Tapp (1982). Plant seedlings exposed after germination for 14 days showed no reduction of growth at 1,000 mg/kg dry soil (OECD draft guideline, 1981, no further details available).

Eisenia fetida was exposed to Quaternary ammonium compounds, di-C16 -18 (even numbered) - alkyldimethyl, chlorides (solved in methanol, 76.1% active ingredient) incorporated into artificial soil consisting of 9.4% organic matter, 70% fine sand and 20% kaolinite clay (Coulson et al. (1989). At the only concentration of the definitive test with 1,000 mg active ingredient/kg dry soil no mortality, no significant reduction in body weight nor any behavioral effects were observed after 14 days.

Concerning the toxicity of Quaternary ammonium compounds, di-C16 -18 (even numbered) - alkyldimethyl, chlorides to soil microorganisms two studies are cited in the ECETOC report (1993) for which no test protocols are available. However, they can give a rough indication on possible effects. Soil respiration was measured with soil samples amended with 12.3 g activated sludge and 365 mg / per kg standard soil (Täuber et al. (1986). After 28 days no depression of oxygen uptake could be measured. In a study of Procter & Gamble (Procter & Gamble (1992). unpublished study, cited in ECETOC 1993) two different soils containing 400mg/kg produced 96 and 119% carbon dioxide compared to the controls over 14 weeks.

Assuming that two trophic levels are covered with long-term data for plants (Windeatt, 1987) and micro-organisms, an assessment factor of 50 could be applied and the following PNEC is calculated: PNECsoil ≥ (1,000 mg/kg / 50)

20 mg/kg.