Propyltriacetoxysilane

Short-term toxicity to fish

Description of key information

Weight of evidence: Based on experimental results obtained in short-term toxicity to fish studies (reliability 2) with supporting substance acetic acid, read-across approach was applied and LC50 (96h) for propyltriacetoxysilane was calculated to be 108.89 mg/L (based on mortality). 

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

108.89 mg/L

Additional information

Weight of evidence:

Read-across from experimental results with acetic acid:

In the first study, Wallen et. al., 1957 (reliability 2), an acute toxicity testwas performed according to OECD Guideline 302. The LC50 (based on mortality) of test material, acetic acid, in Gambusia affinis for 96h exposure period was 251 mg/L. Based on this experimental result, read-across approach was applied and LC50 (96h, based on mortality) for propyltriacetoxysilane was calculated to be 345.97 mg/L.

In the study of Juhnke et. al, 1978 (reliability 2), an acute toxicity test was performed according to German Standard Method for Waste Water and Sludge of 1976 with test material acetic acid. The LC50 for 48h toxicity on the golden orfe (Leuscicus idul melanotus) was 410 mg/L (basis for effect: mortality). Based on this result, read-across approach was applied and LC50 (48h, based on mortality) for propyltriacetoxysilane was calculated to be 565.12 mg/L.

In the study of Mattson et. al., 1976 (reliability 2), Fathead minnow (Pimephales promelas) were exposed under static conditions to a series of concentrations of acetic acid. The 96 h LC50 was 79-88 mg/L (basis for effect: mortality). Based on this experimental result obtained with the supporting substance acetic acid, read-across approach was applied and the LC50 (96h) for propyltriacetoxysilane was calculated to be 108.89-121.29 mg/L (basis for effect: mortality).

Supporting studies:

Read-across from experimental results with sodium acetate:

There are two supporting studies from DeYoung et. al., 1996 and Terhaar et. al., 1972, both with reliability 2 performed for the supporting substance sodium acetate. In the first one and based on the experimental results (120h LC50 = 13330 mg/L for Pimephales promelas), read-across approach was applied and the 120h LC50 for propyltriacetoxysilane was calculated to be 13450 mg/L. In the second study and based on the experimental results (96h LC50 = 10000 mg/L for Pimephales promelas), the read-across approach was applied and the 96h LC50 for propyltriacetoxysilane was calculated to be 10090 mg/L.

According to the available information on short-term toxicity to fish, could be pointed out that the toxicity of propyltriacetoxysilane is caused by the pH effect of acetic acid since the read-across approach applied from experimental data with acetic acid (LC50 (96): 345.97 mg/L; LC50 (48h): 565.12; LC (96h): 108.89 -121.29 mg/L) is much more restrictive than the values obtained with the read-across approach from experimental data with sodium acetate, the neutralised form of the acid (LC50 (120h): 13450 mg/L); LC50 (96h): 10090 mg/L).

Key value for chemical safety assessment:

According to the read-across approaches from experimental results with supporting substance acetic acid, the propyltriacetoxysilane key value for chemical safety assessment is calculated to be LC50 = 108.89 mg/L (based on mortality). This value is the most restrictive and it was obtain by the reach-across approach from the reliable study by Mattson et.al., 1976.