Pentane-2,4-dione

Toxicity to aquatic algae and cyanobacteria

Description of key information

Acetyl acetone is harmful to algae under the conditions of this test. 

Key value for chemical safety assessment

EC50 for freshwater algae:

83.22 mg/L

Additional information

The influence of Acetyl acetone (99.8% pure) on the growth of the freshwater green algae Pseudokirchneriella subcapitata was assessed in a static dose-response test. The study encompassed 6 treatment groups (5 dose rates of the test item of 0.32, 1.0, 3.2, 10, 32 mg test item/L and a control) with three replicates per test concentration and six replicates for the control. The concentration of acetyl acetone was determined by measurement of TOC (= Total Organic Carbon). For the aged test media the stability of the test item could not be confirmed, since identification of the test item (e.g. by retention time or mass transition) is not possible by using TOC-method. Therefore, different analytical methods were tried to be established for selective measurement of the test item in aqueous test media in the required concentration range (including gas chromatography and HPLC). Thus, the identity of acetylacetone in the aged test media could not be demonstrated by a selective analytical method. However, the statement that the test item is not expected to evaporate or react is confirmed by the measurement of TOC, since the carbon content is still close to 100 % in the aged test media. The 72-hour EC50 value was calculated to be 83.22 mg test item/L for the parameter growth rate, 8.36 mg test item/L for the parameter yield. The 72-hour NOEC was determined to be 3.2 mg test item/L, for the parameters growth rate and yield, respectively. The associated 72-hour LOEC was determined to be 10 mg test item/L for the parameter growth rate and yield (Böttcher, IBACON 2010).

 

The acute aquatic toxicity of the substance was investigated in the algal species Scenedesmus sp . After an exposure time of 24 hours the EC10- and EC50-values were determined to be 100 mg/l and > 300 mg/l, respectively (Krebs 1985). The EC10-value from this test can be regarded as long-term effect value for algae.

Data on the toxicity of 2,4-pentanedione on the algae species Scenedesmus quadricauda are also available. The toxicity threshold (TT = EC3) after a 8 d exposure period has been determined to be 2.7 mg/l (Bringmann and Kuehn 1980). As there is no information whether the algae were in the exponential growth phase during the whole test, these data cannot be used for the effects assessment. [modified from OECD SIDS Dossier]