Nitrobenzene

Toxicity to terrestrial plants

Administrative data

Endpoint:

toxicity to terrestrial plants

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: According to EU RAR 2005 no EC50 or NOEC can be derived from this study.

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Effect, uptake and disposition of nitrobenzene in several terrestrial plants

Author:

McFarlane C, Pfleeger T

Year:

1990

Bibliographic source:

Environ Tox Chem 9: 513 - 520

Reference 2

Reference Type:

secondary source

Title:

European Union Risk Assessment Report, Nitrobenzene, CAS No: 98-95-3

Author:

European Chemicals Bureau

Year:

2007

Bibliographic source:

3rd Priority List, Volume: 77

Report date:

2007

Materials and methods

Test material

Test material information

Constituent 1

Reference substance name:

Nitrobenzene

EC Number:

202-716-0

EC Name:

Nitrobenzene

Cas Number:

98-95-3

Molecular formula:

C6H5NO2

IUPAC Name:

nitrobenzene

Sampling and analysis

Analytical monitoring:

not specified

Results and discussion

Any other information on results incl. tables

In a 72 hours phytotoxicity test eight species of plants were exposed to nitrobenzene in exposure chambers (McFarlane et al., 1990). All plant species examined in this study were provided with nutrient medium containing nitrobenzene. Phytotoxicity to nitrobenzene varies considerably between species. When roots were dosed at 8 mg/l the photosynthesis and transpiration responses vary from no effect to complete suppression. No visible symptoms or changes in the transpiration or photosynthetic rates occurred with soybeans (glycine maximus), barley (hordeum vulgare), honeysuckle (lonicera tatarica) and poplar (populus robusta). For these species the 72 h NOEC ≥ 8 mg/l. Green ash (fraxinus pennsylvanica) and lettuce (lactuca sativa) showed no visible symptoms but suffered an initial decrease in both transpiration and photosynthesis rate. The ash plants started recovery after about 10 hours. Lettuce plants recovered much more slowly, the photosynthetic rate started to increase after about 60 hours. Two Elaeagnus species seem to be the most sensitive to nitrobenzene. Autumn olive (Elaeagnus umbellata) did not survive the dosing of 8 mg/l (LC100 = 8 mg/l). Shortly after dosing the transpiration and photosynthetic rate decreased rapidly and did not recover, leaves dropped spontaneously and by the end of the study all remaining leaves dropped when the plants were touched. Russian olive plants (Elaeagnus angustifolia) were similar to the autumn olive in that some of the leaves on some of the plants dropped. However, the newest leaves and all leaves on one plant remained intact and continued to function (photosynthesis and transpiration), although at reduced rates. Recovery started after about 10 hours and was complete at the end of the experiment. Inhibition of root growth of soybean plants (glycine maximus) without an accompanied impairment of transpiration and photosynthesis rate was also observed (Fletcher J et al., 1990). The plants were exposed to nitrobenzene concentrations of 0.02 to 100 mg/l via roots and harvested after 72 hours. The lower concentration of nitrobenzene did not appear to cause plant damage or alter shoot growth. But a visual examination of roots before and after nitrobenzene exposure indicated that the highest concentration inhibited root growth.