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Ecotoxicological information

Toxicity to terrestrial plants

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Reference
Endpoint:
toxicity to terrestrial plants, other
Remarks:
short term and long term studies
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Justification for type of information:
REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
This read-across is based on the hypothesis that source and target substances have similar toxicological properties because
• they are manufactured from similar or identical precursors under similar conditions
• they share structural similarities with common functional groups: quaternary ammonium and saturated or unsaturated alkyl chains with comparable length (corresponding to scenario 2 of the read-across assessment framework)

The read-across hypothesis is based on structural similarity of target and source substances. Based on available experimental data, including key physicochemical properties and data from acute toxicity, irritation, sensitization (human) and genotoxicity studies, the read-across strategy is supported by a quite similar toxicological profile of all substances.

Therefore, read-across from the existing ecotoxicity, environmental fate and toxicity studies conducted with the source substances is considered as an appropriate adaptation to the standard information requirements of the REACH Regulation for the target substance, in accordance with the provisions of Annex XI, 1.5 of the REACH Regulation.

A justification for read-across is attached to IUCLID section 13.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
See justification for read-across attached to IUCLID section 13.

3. ANALOGUE APPROACH JUSTIFICATION
See justification for read-across attached to IUCLID section 13.

4. DATA MATRIX
See justification for read-across attached to IUCLID section 13.
Reason / purpose:
read-across: supporting information
Reason / purpose:
read-across source
Species:
Sinapis alba
Species:
Triticum aestivum
Species:
other: Linum utisatissimum
Species:
Sorghum bicolor
Species:
Helianthus annuus
Species:
Avena sativa
Species:
Brassica rapa
Species:
Sinapis alba
Duration:
14 d
Dose descriptor:
other: EC5
Effect conc.:
1 400 mg/kg soil dw
Basis for effect:
growth
Species:
Triticum aestivum
Duration:
14 d
Dose descriptor:
other: EC5
Effect conc.:
> 1 000 mg/kg soil dw
Basis for effect:
growth
Species:
other: Linum utisatissimum
Duration:
14 d
Dose descriptor:
other: EC5
Effect conc.:
> 1 000 mg/kg soil dw
Basis for effect:
growth
Species:
Sorghum bicolor
Duration:
28 d
Dose descriptor:
NOEC
Effect conc.:
1 000 mg/kg soil dw
Basis for effect:
growth
Species:
Sorghum bicolor
Duration:
25 d
Dose descriptor:
EC50
Effect conc.:
2 530 mg/kg soil dw
Basis for effect:
growth
Species:
Helianthus annuus
Duration:
25 d
Dose descriptor:
NOEC
Effect conc.:
1 000 mg/kg soil dw
Basis for effect:
growth
Species:
Helianthus annuus
Duration:
28 d
Dose descriptor:
EC50
Effect conc.:
2 930 mg/kg soil dw
Basis for effect:
growth
Species:
Avena sativa
Duration:
14 d
Dose descriptor:
NOEC
Effect conc.:
1 000 mg/kg soil dw
Basis for effect:
germination
Species:
Brassica rapa
Duration:
14 d
Dose descriptor:
NOEC
Effect conc.:
1 000 mg/kg soil dw
Basis for effect:
growth

Description of key information

Key value for chemical safety assessment

Short-term EC50 or LC50 for terrestrial plants:
2 530 mg/kg soil dw
Long-term EC10, LC10 or NOEC for terrestrial plants:
1 000 mg/kg soil dw

Additional information

No experimental data are available for the target substance Di-C12-18 alkyldimethyl ammonium chloride. However, plant toxicity studies are available for the closely related source substance DHTDMAC. A justification for read-across is attached to IUCLID section 13.

 

“The toxicity of DHTDMAC 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 DHTDMAC 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 DHTDMAC (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 DHTDMAC 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. ForPhaseolus aureusthe 28 d EC50 was > 10 g/kg.

Similar results were reported for Avena sativa and Brassica rapa (Stanley & Tapp, 1982, cited in ECETOC, 1993). Plant seedlings exposed after germination for 14 days showed no reduction of growth at 1,000 mg DHTDMAC/kg dry soil (OECD draft guideline, 1981, no further details available).” EU RAR, 2002.