Registration Dossier

Ecotoxicological information

Toxicity to terrestrial plants

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

An OECD 208 GLP study was conducted on 6 plant species from 6 different families, respecting the ratio 4 dicotyledonous for 2 monocotyledonous. No biologically significant effect were seen on emergence, survival or phytotoxicity. However, heptanoic acid reduced the growth of 4 species. Brassica rapa was by far the most sensitive species. The EC10 considered for risk assessment is 1.2 mg/kg soil dry weight.

Key value for chemical safety assessment

Long-term EC10, LC10 or NOEC for terrestrial plants:
1.2 mg/kg soil dw

Additional information

The long-term toxicity of heptanoic acid to plants was investigated through an OECD 208 GLP study and using 6 different plant species (4 dicotyledonous and 2 monocotyledonous) from 6 different plant families representing an area as wide as possible across the phylogenetic distribution of the plant kingdom. The 6 species were Brassica rapa (Brassicaceae), Lactuca sativa (Asteraceae), Beta vulgaris (Amaranthaceae), Glycine max (Fabaceae), Allium cepa (Liliaceae) and Lolium perenne (Poaceae). The nominal tested concentrations tested were 0 ; 0.3 ; 1 ; 3 ; 10 ; 30 ; 100 mg/kg soil (dry weight) for all plant species. Thirty seeds per treatment and per species were used. The experiment for the dicotyledonous species was carried out in decaplicate (10 independent pots per treatment) while it was carried out in hexaplicate for the monocotyledonous plants. During the 21 days incubation, seedling emergence, plant mortality and phytotoxicity were recorded. After 21 days incubation (end of the test), the dry weight of shoot per pot was measured. There were no biologically significant effect of heptanoic acid on emergence, survival and phytotoxicity in any species. There were however an inhibitory effect of heptanoic acid on plant growth (as measured by shoot dry weight) on Beta vulgaris, Brassica rapa, Lactuca sativa and Lolium perenne. The most sensitive species was by far Brassica rapa, with an EC10 of 1.2 mg/kg soil dry weight (based on initially measured concentrations in soil).