(1S,5S)-2,6,6-trimethylbicyclo[3.1.1]hept-2-ene

Endpoint summary

Description of key information

Short-term fish toxicity:

One reliable study is available for the substance itself. Fish (Danio rerio) were exposed to (-)-alpha-pinene at nominal test concentrations of 0.10, 0.20, 0.30, 0.60 and 1.00 mg/L over a test period of 96 hours (semi-static test, daily renewal, closed conditions). Concentrations were analytically verified at the start and daily until the end of the test. The concentration of the test item was not satisfactorily maintained within ± 20% of the initial concentration throughout the test. Thus, the endpoint were based on the geometric means of the measured concentrations. The 96h-LC50 was determined to be 0.303 mg/L, the LC0 and LC100 were 0.187 mg/L and 0.578 mg/L, respectively.

 

Short-term toxicity to aquatic invertebrates:

One reliable study is available for the substance itself. The toxicity of (-)-alpha pinene to freshwater Daphnia magna was studied according to OECD 202 and GLP. Daphnids were exposed to the substance at nominal test concentrations of 0.2, 0.3, 0.4, 0.7, 1.0 and 1.5 mg/L over a test period of 48 hours (semi-static test, daily renewal, closed conditions). Concentrations were analytically verified at the start and daily until the end of the test (old and new test media). The concentration of the test item was not satisfactorily maintained within ± 20% of the initial concentration throughout the test. Thus, the endpoint was based on the geometric means of the measured concentrations. The 48h-EC50 was determined to be 0.475 mg/L, the EC0 and EC100 were 0.156 mg/L and 1.190 mg/L, respectively.

Toxicity to algae and cyanobacteria:

One reliable study is available for the substance itself. The toxicity of (-)-alpha-pinene on Pseudokirchneriella subcapitata was studied in accordance with GLP and OECD guideline 201.

A slight inhibition (38.5 %) was recorded at 24 h at the limit test concentration in comparison to control cultures, but no significant inhibition of the growth rate was recorded during the remainder of the test (8% at t = 48 h and 0% at t = 72 h).

Chemical analyses revealed severe test item losses in the presence and absence of algae from the first day. These test item losses were more likely due to a photodegradation phenomenon or another abiotic degradation characteristic of the test item.

The 48-h LOEC and NOEC values of (-)-alpha pinene on Pseudokirchneriella subcapitata were estimated to be 0.494 and 0.247 mg/L, respectively. After 72 h, no effect of the test item on Pseudokirchneriella subcapitata was observed at the solubility/saturation limit of the test item in the test water.

Additional information

Solubility of (-)-alpha-pinene in water

The water solubility of the test item was determined using the slow-stirring method and the column elution method according to OECD guideline 105 and 123.

The water solubility of the test substance at 20 °C was 2.75 mg/L.

 

Poorly water-soluble substances are substances with a limit of water solubility below 100 mg/L according to OECD guideline n° 23 (2000) on aquatic toxicity testing of difficult substances and mixtures. Therefore, (-)-alpha-pinene meets the definition of poorly water soluble substances and has to be considered as a "difficult substance to test".

Available ecotoxicological information

Short-term fish toxicity:

One reliable study is available for the substance itself. Fish (Danio rerio) were exposed to (-)-alpha-pinene at nominal test concentrations of 0.10, 0.20, 0.30, 0.60 and 1.00 mg/L over a test period of 96 hours (semi-static test, daily renewal, closed conditions). Concentrations were analytically verified at the start and daily until the end of the test. The concentration of the test item was not satisfactorily maintained within ± 20% of the initial concentration throughout the test. Thus, the endpoint were based on the geometric means of the measured concentrations. The 96h-LC50 was determined to be 0.303 mg/L, the LC0 and LC100 were 0.187 mg/L and 0.578 mg/L, respectively.

 

Short-term toxicity to aquatic invertebrates:

One reliable study is available for the substance itself. The toxicity of (-)-alpha pinene to freshwater Daphnia magna was studied according to OECD 202 and GLP. Daphnids were exposed to substance at nominal test concentrations of 0.2, 0.3, 0.4, 0.7, 1.0 and 1.5 mg/L over a test period of 48 hours (semi-static test, daily renewal, closed conditions). Concentrations were analytically verified at the start and daily until the end of the test (old and new test media). The concentration of the test item was not satisfactorily maintained within ± 20% of the initial concentration throughout the test. Thus, the endpoint was based on the geometric means of the measured concentrations. The 48h-EC50 was determined to be 0.475 mg/L, the EC0 and EC100 were 0.156 mg/L and 1.190 mg/L, respectively.

Toxicity to algae and cyanobacteria:

One reliable study is available for the substance itself. The toxicity of (-)-alpha-pinene on Pseudokirchneriella subcapitata was studied in accordance with GLP and OECD guideline 201.

A slight inhibition (38.5 %) was recorded at 24 h at the limit test concentration in comparison to control cultures, but no significant inhibition of the growth rate was recorded during the remainder of the test (8 % at t = 48 h and 0 % at t = 72 h).

Chemical analyses revealed severe test item losses in the presence and absence of algae from the first day. These test item losses were more likely due to a photodegradation phenomenon or another abiotic degradation characteristic of the test item.

The 48-h LOEC and NOEC values of (-)-alpha pinene on Pseudokirchneriella subcapitata were estimated to be 0.494 and 0.247 mg/L, respectively. After 72 h, no effect of the test item on Pseudokirchneriella subcapitata was observed at the solubility/saturation limit of the test item in the test water.

Toxicity to microorganisms:

The concentration tested in the ready biodegradbility study (2 mg/L) conducted on alpha-pinene multiconstituent is taken as conservative NOECmicrorganism.