Acrylaldehyde

Toxicity to terrestrial plants

Description of key information

exposure via irrigation
bean, clover, corn and millet: NOEC=50 mg/l
cucumber and tomatoes: LOEC=40 mg/l
vegetable seedlings: NOEC<25 mg/l
exposure via air
lily pollen: 1 h EC10 (assumed to be equal to a NOEC)=0.9 mg/m³
alfalfa: 9 h LOEC=0.2 mg/m³
seeds of wheat: 24 h LOEC=50 mg/l in 1.1-L vessel)

Additional information

1. European Union Risk Assessment Report of Acrolein (EU, 2001)

Effects of acrolein treated water on terrestrial plants

The effects of acrolein on various crops grown on soil irrigated by acrolein treated water were investigated. The concentrations varied between 15 and 50 mg/l of supply water. The effect levels differed among the crops tested. No effects were observed in bean, clover, corn and millet at 50 mg/l. Slight damage to foliage was observed in cucumbers and tomatoes at 40 mg/l, whereas cotton foliage was damaged significantly at 25 mg/l. Vegetable seedlings in contact with treated water were damaged even at the lowest concentrations used.

Effects of airborne acrolein on terrestrial plants

There are a limited number of studies in which the phytotoxicity of airborne acrolein [on lily pollen ] is investigated. The implication is that the inhibition of pollen germination will be reflected as an adverse effect on reproductive capacity of a plant species. Acrolein proved to be more toxic to pollen than any of the other compounds tested. At a 2 hour exposure of 0.9 mg/m³, acrolein caused a 60% decrease in pollen tube elongation; at 3 mg/m³ it completely prevented extension of the pollen tube. The 1 hour EC₁₀ (assumed to be equal to a NOEC) was found to be 0.9 mg/m³. Having previously observed that exposure to acrolein at 1.1 mg/m³ for 6 hours caused acute foliar injury to lily, the authors concluded that lily pollen was as sensitive as foliage to acrolein treatment.

In an effort to simulate the plant injury observed in California as a result of so-called smog in the mid-1940s, exposed five plant species that appeared to be the most sensitive in the field (spinach, endive, alfalfa, oats and beets), to a variety of organic and inorganic compounds. The experiments were carried out in a fumigation chamber at concentrations generally less than 2 mg/m³. Several aldehydes, including acrolein, were among the compounds tested. Exposure of acrolein at 0.2 mg/m³for 9 hours caused symptoms on alfalfa resembling natural smog damage, but there was no suggestion of damage to the other species. Higher doses of acrolein (1.3 mg/m³ for 3 hours or 2.6 mg/m³ for 4.5 hours) produced numerous sunken pits on both surfaces of spinach, endives and beets, but the injury was unlike that observed in the field.”

2. Agreement with further international Reports and Studies published after finalisation of the EU Risk Assessment Report 2001  

WHO (2002): The data on toxicity of acrolein in air to terrestrial plants are limited to three acute studies on crop plants. Smog-like leaf damage was observed for seven species exposed to concentrations of acrolein ranging from 233 to 4700 μg/m³. The most sensitive plant tested was alfalfa (Medicago sativa), which developed speckled surface necrosis (percentage effect not given) after a 9-h exposure to 233 μg acrolein/m³, the lowest concentration tested. This concentration corresponded to a NOEC for the four other species of crop plants tested in that study (sugar beet, Beta sp.; endive, Cichorium endivia; spinach, Spinacia oleracea; oats, Avena sp.). The method of exposure involved the vaporization of liquid acrolein continuously injected into a fumigation chamber. In a study of the Easter lily (Lilium longiflorum) seed, there was a complete inhibition of pollen tube elongation following a 5-h exposure to 910 μg acrolein/m³. Pinto beans (Phaseolus sp.) exposed to 4700 μg acrolein/ m³ in air for 1.2 h exhibited 10% surface damage.”

3. Substantial disagreements in comparison to further international Reports to European Union Risk Assessment Report 2001

None

4. Additional aspects in further international Reports

None

5. Additional information in newer Studies, not included in the European Union Risk Assessment Report 2001 or further cited international reports

Fumigation of seeds of wheat with acrolein with 50 mg/L for 24 h in closed glass jar resulted in significantly decreased the germination potential and reduced plumule length in comparison with unfumigated seed. Results from vigour test after 4 days were unchanged after 8 days (total germination test).

6. Conclusions

The effects of acrolein on various crops grown on soil irrigated by acrolein treated water were investigated. NOEC for bean, clover, corn and millet was 50 mg/l.  The LOEC for cucumbers and tomatoes was 40 mg/l, slight damage to foliage was observed. The NOEC for vegetable seedlings in contact was 25 mg/l, the lowest concentration used.

The effect of acrolein in air to the inhibition of pollen germination as a reflector of reproductive capacity of a plant species was assessed with lily pollen. The 1 hour EC₁₀ (assumed to be equal to a NOEC) was found to be 0.9 mg/m³. Having previously observed that exposure to acrolein at 1.1 mg/m³ for 6 hours caused acute foliar injury to lily, the authors concluded that lily pollen was as sensitive as foliage to acrolein treatment.

Exposure of acrolein in a fumigation chamber at 0.2 mg/m³ for 9 hours caused symptoms on alfalfa (the most sensitive species in the test) resembling natural smog damage.

Fumigation of seeds of wheat with acrolein with 50 mg/L for 24 h in closed glass jar resulted in significantly decreased the germination potential and reduced plumule length in comparison with unfumigated seed. Results from vigour test after 4 days were unchanged after 8 days (total germination test). As no information is available about the concentration of fumigated acrolein in the air (effect values are expressed as test concentrations dropped on the blotting paper strips inserted in the test containers) these results are used for supportive information.