isopropanol;isopropyl alcohol;propan-2-ol

Toxicity to terrestrial plants

Description of key information

IC50 (germination) = 2104 mg/kg, 3 day, Lactuca sativa (Reynolds, 1977)

Key value for chemical safety assessment

Short-term EC50 or LC50 for terrestrial plants:

2 104 mg/kg soil dw

Additional information

The toxicity of 2-propanol to the seed germination of the dicotyledon Lactuca sativa (garden lettuce) was assessed in a published non-guideline study that predates GLP requirements for ecotoxicity studies (Reynolds, 1977). This laboratory study used Great Lakes garden lettuce seeds sown in aluminium boxes (4.2 x 2.1 x 1.6 cm) with glass windows in the lids, containing 0.5% agar (8 mL) in which appropriate weights of 2-propanol were dissolved. Germination at 30ºC was recorded after 3 days. The results indicate that 35 mM of 2-propanol caused 50% inhibition of the germination of lettuce seeds. The molecular weight of 2-propanol is 60.1 g/mol and thus, the 50% inhibition value can be calculated to be 2104 mg/kg in the agar.

 

This study did not investigate any monocotyledon species and with only one dicotyledon species reported, it is difficult to establish an effect level that will be representative of the effects of 2-propanol on seedling emergence of higher plants.

Although the reliability of this study could not be sufficiently assessed, the result based on a 96 hours test supports that IPA also beyond 24h exposure does not pose significant hazard to invertebrates. Also, these results are consistent with observations on acute fish studies performed over 48 hours in a static test as well as in a flow through test, proving that the substance does not volatilize from test water within 48 hours.