Benzyltoluene

Long-term toxicity to fish

Administrative data

Endpoint:

adult fish: sub(lethal) effects

Type of information:

experimental study

Adequacy of study:

disregarded due to major methodological deficiencies

Study period:

From the 20th February to the 9th April, 1987

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

significant methodological deficiencies

Remarks:

This study is not considered a long-term study. In addition, adverse effects were observed at concentrations far above water solubility limit.

Cross-reference

Reason / purpose:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1987

Report Date:

1987

Materials and methods

Test guideline

Qualifier:

according to

Guideline:

OECD Guideline 204 (Fish, Prolonged Toxicity Test: 14-day Study)

Deviations:

yes

Remarks:

Details on test animals, system and test medium were not provided, no analytical monitoring.

GLP compliance:

yes

Remarks:

Reported only for the conservation of the study data and tested material inside the laboratory

Test material

Reference

Name:

Unnamed

Type:

Constituent

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
- Water solubility (under test conditions): 400 ppm

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Test substance was dissolved in acetone and then disolved in the assay water (constant volume: 1 mL of acetone/L of water). The solutions obtained are distributed in test containers (capacity 2 L) at a rate of 1 L/h.

Test organisms

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

20 fishes per test recipient were used for the test substance and negative control (with and without acetone) assays. 10 fishes per concentration were tested in the reference substance (potassium dichromate) assay.

Study design

Test type:

flow-through

Water media type:

not specified

Limit test:

no

Total exposure duration:

14 d

Post exposure observation period:

None

Test conditions

Hardness:

no data

Test temperature:

23 °C

pH:

Varied from 6.88 to 7.69 acoording to the concentration tested and the day of measurement.

Dissolved oxygen:

The concentration in dissolved oxygen measured at the end of the test was equal to at least 60% of the saturation (corresponding to 8.3 mg/L at 23°C), except for the vehicle control. The measured range in vehicle control was 4.2 to 5.7 mg/L; for the whole other test concentrations, the measured range was 4.7 to 6.8 mg/L.

Salinity:

Freshwater.

Nominal and measured concentrations:

Nominal tested concentrations: 1, 2.5, 3.5, 5, 10, 15, 20, 30 and 40 mg/L.

Details on test conditions:

TEST CONCENTRATIONS
- Spacing factor for test concentrations: between 1.3 and 2
- Range finding study
- Test concentrations: 0, 1, 2.5, 5, 25, 50 (96 h)
- Results used to determine the conditions for the definitive study: LC0 = 2.5 mg/L and LC100 = 50 mg/L

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Duration:

14 d

Dose descriptor:

LC50

Effect conc.:

2.53 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: Mortality was observed above water solubility limit only

Details on results:

- Cumulative mortality at each concentration and for each recommended observation time if possible:

. 1 mg/L: 15% (cumulative mortality)
Day 11 : 15% (no observation on Week-end: Days 9 and 10)

. 2.5 mg/L: 25% (cumulative mortality)
Day 9 : 15%
Day 12 : 25% (no observation on Week-end: Days 10 and 11)

. 3.5 mg/L: 85% (cumulative mortality)
Day 4 : 55% (no observation on Week-end: Days 2 and 3)
Day 8 : 70%
Day 11 : 85% (no observation on Week-end: Days 9 and 10)

. 5 mg/L: 80% (cumulative mortality)
Day 4 : 20% (no observation on Week-end: Days 2 and 3)
Day 6 : 35%
Day 7 : 45%
Day 8 : 55%
Day 9 : 65%
Day 12 : 80% (no observation on Week-end: Days 10 and 11)

. 10 mg/L: 100% (cumulative mortality)
Day 1 : 50%
Day 4 : 100% (no observation on Week-end Day 3)

. 15 mg/L: 100% (cumulative mortality)
Day 1 : 65%
Day 2 : 100%

. 20 mg/L: 100% (cumulative mortality)
Day 1 : 90%
Day 2 : 100%

. 30 mg/L: 100% (cumulative mortality)
Day 2 : 100% (no observation reported on Day 1)

. 40 mg/L: 100% (cumulative mortality)
Day 1 : 100%

- Mortality in the controls:
No mortality in any control groups

- Behavioural observation of the fish:
No other toxicity effect other than mortality was observed in any animals.

Results with reference substance (positive control):

- Results with reference substance valid? yes (according to French Guidelines AFNOR 90 303 - June 1985): LC50 at 24 h lies between 200 and 400 mg/L
- LC50: 259.9 mg/L

Reported statistics and error estimates:

No statistics performed, graphical evaluation of the LC50 values.

Any other information on results incl. tables

Table 1: Fish mortality rate in the 14-day study

Tested Concentration [mg/L]	Mortality rate throughout the 14-d study period
	Number of individuals (n/20)	%
Blank control	0	0
Vehicle control	0	0
1	3	15
2.5	5	25
3.5	17	85
5	16	80
10	20	100
15	20	100
20	20	100
30	20	100
40	20	100

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

No mortality in control tests, measured dissolved oxygen always at least 60% of saturation, reference substance assay (only 24 h) considered valid

Conclusions:

The 14d-LC50 of the test item tested with Brachydanio rerio was determined to be 2.53 mg/L, which is far above water solubility limit of the test item.

Executive summary:

In this prolonged acute toxicity test on fish performed according to the OECD Guidelines 204, 20 fishes (Brachydanio rerio) per concentration were exposed to JARYLEC C (Benzyl/dibenzyltoluene) during 14 days. The substance was administered to fish in test water after it had been dissolved in acetone. The resulting LC50 of JARYLEC C was determined to be 2.53 mg/L after 14 days. Mortality was observed at all concentrations tested, except in the control groups. At the lowest concentration tested (i.e. 1 mg/L), 3/20 animals died throughout the study period. All tested concentrations were above water solubility limit of the registered substance. Therefore, the results are considered irrelevant for regulatory purposes. This study is disregarded.