Registration Dossier

Administrative data

Endpoint:
toxicity to terrestrial plants: long-term
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Results published in a scientific review and peer-reviewed in the European RAR.

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1987

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 208 (Terrestrial Plants Test: Seedling Emergence and Seedling Growth Test)
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
75% active ingredient

Sampling and analysis

Analytical monitoring:
no

Test substrate

Vehicle:
not specified
Details on preparation and application of test substrate:
Potting compost with about 80% sand/gravel and 20% silt/clay including 4% organic matter was used as substrate.

Test organisms

open allclose all
Species:
Phaseolus aureus
Plant group:
Dicotyledonae (dicots)
Species:
Helianthus annuus
Plant group:
Dicotyledonae (dicots)
Species:
Sorghum bicolor
Plant group:
Monocotyledonae (monocots)

Study design

Test type:
seedling emergence toxicity test
Study type:
laboratory study
Substrate type:
artificial soil
Limit test:
no
Total exposure duration:
21 d

Test conditions

Reference substance (positive control):
not specified

Results and discussion

Effect concentrationsopen allclose all
Species:
Sorghum bicolor
Duration:
21 d
Dose descriptor:
EC50
Effect conc.:
2 530 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
other: fresh weight of seedlings
Species:
Helianthus annuus
Duration:
21 d
Dose descriptor:
EC50
Effect conc.:
2 930 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
other: fresh weight of seedlings
Species:
Phaseolus aureus
Duration:
21 d
Dose descriptor:
EC50
Effect conc.:
> 10 000 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
other: fresh weight of seedlings
Species:
Sorghum bicolor
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
> 1 000 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
growth
Species:
Helianthus annuus
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
> 1 000 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
growth
Species:
Phaseolus aureus
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
> 10 000 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
growth
Species:
other: Sorghum bicolor, Helianthus annuus and Phaseolus aureus
Duration:
7 d
Dose descriptor:
NOEC
Effect conc.:
> 10 000 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
seedling emergence
Details on results:
The highest test material concentrations which caused no growth reduction at the 95% significance level were ≥ 1,000 mg/kg for sorghum and sunflower and ≥ 10,000 mg/kg for mung bean.
The 7-day EC50 for seed emergence (the concentration at which seedling emergence was 50% of that recorded in the control by the seventh day after sowing) was greater than the highest concentration tested (10,000 mg/kg) for all tested species.

Applicant's summary and conclusion

Validity criteria fulfilled:
not specified
Executive summary:

The influence of DHTDMAC (76.1% active ingredient = quartenary ammonium) on the emergence of plant seedlings and the early growth stages of Sorghum bicolor, Helianthus annuus and Phaseolus aureus has been invetsigated (Windeatt, 1987).

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. For Phaseolus aureus the 28 d EC50 was > 10 g/kg.