Butyl (S)-2-hydroxypropionate

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1991-08-08 to 1992-04-10

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations:18, 32, 56, 100 and 180 mg/L
- At t = 24 h samples were taken from the control medium and from the freshly prepared test solutions of 18, 32 and 56 mg/L. At t = 48 h samples of the "spent" control medium and the same "spent" test solutions were taken.
- Sampling method: Samples of 50 mL were taken in glass bottles and immediately transported under cooled conditions to the analytical department of TNO
- Sample storage conditions before analysis: Refrigerated

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Five concentrations of butyl-(S)-lactate were tested. DSWL was used as a control medium. A quantity of 1 gram was accurately weighed out and dissolved in 1 litre DSWL. Portions of 27, 48, 84, 150 and 270 mL were each diluted to 1.5 litre, resulting in test solutions of 18, 32, 56, 100 and 180 mg/L. New concentrated solutions were prepared daily throughout the test period.
- Controls: DSWL
- Evidence of undissolved material (e.g. precipitate, surface film, etc): no, freshly prepared solutions of the test substance appeared to be completely dissolved (visually assessed) at all concentrations tested throughout the test

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebra fish
- Strain: No data
- Source: M.B. Ruysbroek B.V. (Noordvliet 159, Maassluis)
- Length at study initiation: 2.1 ± 0.17 cm
- Weight at study initiation: 0.07 ± 0.018 g
- Method of breeding: No data
- Feeding during test: No

ACCLIMATION
No information provided.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

No

Hardness:

220 mg/L.

Test temperature:

24.2–24.7 °C

pH:

7.8–8.2; at the beginning and at the end of the test and at each replacement time (in the spent solutions just after replacement and in the newly prepared solutions just after dosing) the pH and the oxygen concentration of the test solutions and control medium were measured. They were also measured after 2 h in the test solutions of 180 mg/L because all animals had died.

Dissolved oxygen:

5.8-8.6 mg/L; At the beginning and at the end of the test and at each replacement time (in the spent solutions just after replacement and in the newly prepared solutions just after dosing) the pH and the oxygen concentration of the test solutions and control medium were measured. They were also measured after 2 h in the test solutions of 180 mg/L because all animals had died.

Nominal and measured concentrations:

See table 1.

Details on test conditions:

TEST SYSTEM
- Test vessel: 2000 mL glass beakers, each containing 1500 mL of test solution or control medium
- Type (delete if not applicable): open
- Aeration: The test solutions and control medium were slightly aerated and replaced daily.
- Renewal rate of test solution (frequency/flow rate): once a day
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1; one beaker containing 10 fishes was used for each test solution and the control medium.
- No. of vessels per control (replicates): 1; one beaker containing 10 fishes was used for each test solution and the control medium.

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Dilution water used was DSWL, prepared from ground water. This DSWL has proven to be suitable for the culture of Brachydanio rerio.
- Total organic carbon: 2 mg/L
- Metals: Na 1.26 mmol/L, K 0.23 mmol/L, Ca 1.41 mmol/L , Mg 0.78 mmol/L
- Chlorine: 2.81 mmol/L

OTHER TEST CONDITIONS
- Adjustment of pH: NA
- Photoperiod: The test was carried out under a 16 h light-8 h dark regime with transition periods of 30 minutes in a temperature controlled room of 25 ± 1°C.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Mortality (LC50 and NOEC)

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8
- Range finding study: yes, appropriate concentrations were determined in a preliminary range finding test
- Test concentrations: Five concentrations of butyl-(S)-lactate were tested. DSWL was used as a control medium. A quantity of 1 gram was accurately weighed out and dissolved in 1 litre DSWL. Portions of 27, 48, 84, 150 and 270 mL were each diluted to 1.5 litre, resulting in test solutions of 18, 32, 56, 100 and 180 mg/L. New concentrated solutions were prepared daily throughout the test period.
- Results used to determine the conditions for the definitive study: yes

Dead animals were counted and removed after 24 h, 48 h, 72 h and 96 h. At the same times the condition (swimming behaviour, colour, respiratory function or any other observable morphological or visual behavioural criterion) of the survivors was visually compared with that of the control animals. At t = 2 h all test vessels were also checked for mortality and the dead animals counted and removed.

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

75 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95 % CL: 56–100 mg/L

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

56 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: condition

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

56 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

2 h

Dose descriptor:

LC50

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95 % CL: 72–100 mg/L

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

75 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95 % CL: 56–100 mg/L

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

75 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95 % CL: 56–100 mg/L

Duration:

72 h

Dose descriptor:

LC50

Effect conc.:

75 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95 % CL: 56–100 mg/L

Key result

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

42.8 mg/L

Nominal / measured:

nominal

Conc. based on:

other: actual concentration

Basis for effect:

mortality (fish)

Remarks on result:

other: The average actual concentration was 57 % of the nominal concentration during the test.

Details on results:

- Mortality of control: no
- Other adverse effects control: none
- Abnormal responses: records of number of fish and their condition are recorded in table 2
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: substance completely dissolved in all concentrations
- Effect concentrations exceeding solubility of substance in test medium: n/a

Results with reference substance (positive control):

-

Reported statistics and error estimates:

The maximum likelihood estimates of the LC50 values were calculated assuming a log-logistic dose-effect relation. Likelihood-ratio confidence intervals were derived from the confidence intervals.

Sublethal observations / clinical signs:

Table 1: Measured concentrations of butyl (S)-lactate

Nominal concentration of test substance [mg/L]	Measured concentrations
	t = 0 h		t = 48 h
	mg/L	% of nominal	mg/L	% of nominal
0	> 1		< 1
18	14	78	5	28
32	26	81	11	34
56	46	82	23	41
Average % of nominal concentration at t = 0 h and t = 48 h	80		34
Average % of nominal during the test	57

 

Table 2 –Number of surviving fishes at several concentrations of butyl-(S)-lactate and after several exposure times

Time (h)	Nominal concentration of the test substance (mg/L)
	0	18	32	56	100	180
0 2 24 48 72 96	10 10 10 10 10 10	10 10 10 10 10 10	10 10 10 10 10 10	10 10 10 10 10 10	10 2 0 0 0 0	10 0 0 0 0 0

 

Table 3 –Number of fishes and their condition at several concentrations of butyl-(S)-lactate and after several exposure times

Time (h)	Nominal concentration of the test substance (mg/L)
	0	18	32	56	100	180
0 2       24   48 72 96	10^(a) 10       10^(a)   10^(a) 10^(a) 10^(a)	10^(a) 10       10^(b)   10^(b) 10^(b) 10^(b)	10^(a) 10       10^(b)   10^(b) 10^(b) 10^(b)	10^(a) 10       10^(b)   10^(b) 10^(b) 10^(b)	10^(a) 2 2^(c) 8^(d)   0 2^(d) 0 0 0	10^(a) 0 10^(d)     0   0 0 0

The following codes are used to denote condition:

^(a)Condition of all fishes, visually assessed, normal (=good);

^(b)Condition of all fishes, visually assessed, equal to that of the control fishes;

^(c)Number of slow swimming fishes.

^(d)Number of dead fishes

Validity criteria fulfilled:

yes

Conclusions:

The 96-h LC50 of butyl-(S)-lactate to Brachydanio rerio was determined to be 42.8 mg/L (measured concentration). The NOEC was 32 mg/L.

Executive summary:

The 96 h acute toxicity of butyl-(S)-lactate to the fresh-water fish species Brachydanio rerio was determined as described in the OECD Guideline no. 203 and according to the OECD principles of Good Laboratory Practice.

The test was carried out as a semi-static test with daily replacement of the test solutions and with 10 fishes for each concentration. The exposure duration was 96 hours. The nominal concentrations tested were 18, 32, 56,100 and 180 mg/L. The test substance appeared to be completely dissolved at all concentrations tested (visually assessed). The actual concentrations of butyl-(S)-lactate were determined with gas chromatography (direct injection, FID detection). They were between 78 % and 82 % of the nominal concentrations just after dosing (average 80 %). To test the stability of the test substance the concentrations of butyl-(S)-lactate were also analysed after 24 h and appeared to be between 28 % and 41 % of the nominal concentrations (average 34 %). The average actual concentration was 57 % of the nominal concentration during the test.

 

Results synopsis

Test organism size/age (mean wet weight or length): The average total length and weight (± standard deviation) were 2.1 ± 0.17 cm and 0.07 ± 0.018 g respectively.

Test type: Semi-static

The results of the test were (as nominal concentrations):

48h LC50 (mortality): 75 mg/L

96h LC50 (mortality): 75 mg/L

96h LC100 (mortality): 100 mg/L

96h NOEC (mortality = 96h-LC0): 56 mg/L

96h NOEC (condition): 56 mg/L

The average actual concentration was 57 % of the nominal concentration during the test. Adjusted ECx values are the following:

48h LC50 (mortality): 42.8 mg/L

96h LC50 (mortality): 42.8 mg/L

96h LC100 (mortality): 57 mg/L

96h NOEC (mortality = 96h-LC0): 32 mg/L

96h NOEC (condition): 32 mg/L

Endpoints affected: Mortality, other effects (i.e. swimming behaviour, colour, respiratory function or any other observable morphological or visual behavioural criterion)

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Justification for type of information:

For details and justification of read-across please refer to the attached report in section 13 of IUCLID.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

75 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95 % CL = 56–100 mg/L

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

56 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: No data
- Observations on body length and weight: No data
- Other biological observations: No data
- Mortality of control: No data
- Other adverse effects control: No data
- Abnormal responses: No data
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: No data
- Effect concentrations exceeding solubility of substance in test medium: No

Reported statistics and error estimates:

LC50 values and their 95 % confidence interval for survival in the fish test were calculated by means of a parametric model developed by Kooijman (1981) or, if too few concentrations showed partial mortality, by assuming a log-logistic dose-effect relation (van der Hoeven, 1991).

Validity criteria fulfilled:

not specified

Remarks:

Poor documentation, validity cannot be assessed

Conclusions:

The short-term toxicity testing of butyl lactate on freshwater fish (Danio rerio) resulted in an LC50 (96 h) of 75 mg/L (nominal).

Executive summary:

In a 96-h acute toxicity study, zebra fish (Danio reriosyn.Brachydanio rerio) were exposed to butyl lactate at nominal concentrations of 0 (control), 320 and 560 mg/L (further information on the number of concentration levels not available) under semi-static conditions. The 96-h LC50 was 75 mg/L. The NOEC value, based on mortality, was 56 mg/L. Sublethal effects were not reported. Based on the results of this study, butyl lactate would not be classified as hazardous to the aquatic environment according to the CLP Regulation (EC) No 1272/2008.

This toxicity study is classified as supplementary information and does not satisfy the guideline requirement for a fish short-term toxicity study but can nevertheless be used as supportive data.

Results synopsis

Test organism: Zebra fish (Danio rerio, Brachydanio rerio)

Test type: Semi-static

LC50: 75 mg/L (95 % CL = 56–100 mg/L)

NOEC: 56 mg/L

Endpoint(s) effected: Survival/mortality

This information is used in a read-across approach in the assessment of the target substance. For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Description of key information

In a guideline compliant study according to GLP, the LC50 of butyl-S-lactate for mortality of Brachydanio rerio was determined to be 75 mg/L (nominal). The test substance concentrations were analytically monitored and found to be maintained at 57 % of nominal during the test. Therefore, the LC50 value was adjusted to 42.8 mg/L.

This result is confirmed by published results.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

42.8 mg/L

Additional information

The following LC50 values were determined for fish:

LC50 (96h, Brachydanio rerio) = 75 mg/L (Hooftman 1992, according to OECD 203)

LC50 (96h, Brachydanio rerio) = 75 mg/L (Bowmer 1998, according to OECD 203)

The LC50 value for butyl-S-lactate reported by Hooftman (1992) is used as key value. The study is guideline and GLP compliant. The test substance concentrations were analytically monitored and found to be maintained at 57 % of nominal during the test. Therefore, the LC50 value was adjusted to 42.8 mg/L.

As supporting study LC50 values reported by Bowmer (1998) are presented. Due to insufficient documentation it is not clear which isomer of butyl lactate was used in the publication.