6-methylhept-5-en-2-one

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

No GLP, test design issues, hence recalculation of LCx values.

Qualifier:

according to guideline

Guideline:

other: German standard DIN 38 412, Part 15

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

Leuciscus idus

Details on test organisms:

TEST ORGANISM- Common name: Golden Orfe- Length at study initiation (length definition, mean, range and SD): 6.0 cm (range: 5.5-7.1)- Weight at study initiation (mean and range, SD): 1.8 g (range: 1.2-2.8)- Feeding during test: 1 day before and during exposure ACCLIMATION- Acclimation period: 3 days

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

2.5 mmol/l

Test temperature:

21+/-1°C

pH:

7.5 - 7.9

Dissolved oxygen:

7.5 - 8.7 mg/l

Nominal and measured concentrations:

Nominal test concentrations (mg/l):46.6,100,215,464,1000,control

Details on test conditions:

TEST SYSTEM- Test vessel: All-glass aquarium non-sealed (30 x 22 x 24 cm) - Fill volume: 10 l - Aeration: slight- No. of organisms per vessel: 10- No. of vessels per concentration (replicates): 1- No. of vessels per control (replicates): 1- Biomass loading rate: 1.8 g fish/l test waterTEST MEDIUM / WATER PARAMETERS- Source/preparation of dilution water: Dilution water chemistry: reconstituted freshwater was prepared from demineralized tap water that was resalted by the addition of 294.0 mg/l CaCl2*2H2O, 123.3 mg/l MgSO4*7H2O, 63.0 mg/l NaHCO3 and 5.5 mg/l KCl.OTHER TEST CONDITIONS- Photoperiod: 16:8 h day-night regimeEFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality and symptoms of intoxication

Reference substance (positive control):

yes

Remarks:

chloroacetamide

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

50 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: effective concentration due to volatility

Details on results:

96 h NOEC 46.4 mg/L (nominal) based on test material96 h LC0 46.4 mg/L (nominal) based on test material96 h LC100 100 mg/L (nominal) based on test materialIn the control and up to nominal 46.4 mg test item/L, no fish died within 96 h of exposure and displayed no symptoms of intoxication. After 4 h, all fish died at nominal 100, 215, 464 and 1000 mg/l 6-methylhept-5-en-2-one. Thus, using the geometric mean of the LC0 of 46 mg/l and the LC100 of 100 mg/l a LC50 of 68.1 mg/l (geometric mean) could be calculated. Due to a moderate volatility in an experiment using 100 mg and 200 mg of 6-methylhept-5-en-2-one, but without test organisms, the evaporation over 96 hours was observed. After 96 h approximately 23 % and 26 % of the test substance were evaporated (geometric mean of all measured TOC values between 0 h and 96 h), respectively. Therefore, the LC50(96h) can be corrected to be 50 mg/l based on 26% evaporation.

Results with reference substance (positive control):

The 48 h EC50 of the positive control (chloroacetamide) was 32 mg/l.

Validity criteria fulfilled:

not specified

Remarks:

The derivation of the LC50 from the LC0 and LC100 average value can be considered as conservative. The correction for volatility loss instead of using measured data can also be considered as an acceptable approach.

Conclusions:

Acute toxicity 96h-LC50 of Methylheptenone on the fish golden ide (Leuciscus idus L., golden variety) is 50.0 mg/L.

Executive summary:

Following guideline DIN 38 412 (1982), which is very similar to the OECD-303 guideline, the methylheptenone concentrations 46.4, 100, 215, 464 and 1000 mg/L were tested on the Golden Orfe Leuciscus idus in freshwater static conditions. Substance was well dissolved but partially volatilise during the test. In the lower concentration 46.4 mg/L nor symptoms and nor dead were observed, whereas in the next concentration 100 mg/L without observed symptoms all animals were dead as soon as 4 hours after the begining of the test. The pH, oxygen content and other parameters were stable and in the expected levels needed for Fish. The derivation of the LC50 from the LC0 and LC100 average value can be considered as conservative. The correction for volatility loss instead of using measured data can also be considered as an acceptable approach. The comparison with ECOSAR prediction also indicates that the proposed value are coherent. It can therefore be concluded that the Fish 96h-LC50 is 50.0 mg/L.

Description of key information

Acute toxicity to fish was investigated in the golden orfe, Leuciscus idus, in accordance with DIN 38 412 in a static test, not under GLP. Using the geometric mean of the LC0 of 46 mg/l and the LC100 of 100  mg/l a 96h LC50 of 68.1 mg/l could be calculated. Due to a moderate volatility in an experiment using 100 mg and 200 mg of 6-methylhept-5-en-2-one, but without test organisms, the evaporation over 96 hours was observed. After 96 h approximately 23 % and 26 % of the test substance were evaporated  (geometric mean of all measured TOC values between 0 h and 96 h),  respectively. Therefore, the LC50 (96h) can be corrected to be  50 mg/l based on 26% evaporation.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

50 mg/L