4-isopropyl-m-cresol

Long-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

No data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

details on test conditions, test concentrations, reference substance, individual/summary results not reported however, it is stated that the studes were performed in conformtiy with the Guideline thus the quality criteria should have been met in this study. GLP status not reported and study performed after 2008 so not eligible as a valid test under REACH Regulation

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

The three-brood reproduction test was conducted to evaluate the influence of the test item on the survival and reproduction of daphnids (Ceriodaphnia dubia).

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

4-isopropyl-m-cresol

EC Number:

221-761-7

EC Name:

4-isopropyl-m-cresol

Cas Number:

3228-02-2

Molecular formula:

C10H14O

IUPAC Name:

4-isopropyl-m-cresol

Test material form:

not specified

Details on test material:

- Name of test material (as cited in study report): p-thymol
- Source: Wako Pure Chemical Co. (Osaka, Japan)
- Analytical purity: 99%

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
PHYSICO-CHEMICAL PROPERTIES
- Water solubility: 860 mg/L
- log Kow:: 3.52
- pKa: 10.36 ± 0.18

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

not specified

Test organisms

Test organisms (species):

Ceriodaphnia dubia

Details on test organisms:

TEST ORGANISM
- Source: National Institute for Environmental Studies (Tsukuba, Japan)

ACCLIMATION
- Acclimation period: Acclimated in the laboratory of the University of Tokushima at least for 3 months.

Study design

Test type:

semi-static

Water media type:

not specified

Limit test:

no

Total exposure duration:

8 d

Post exposure observation period:

None

Test conditions

Hardness:

No data

Test temperature:

No data

pH:

No data

Dissolved oxygen:

No data

Salinity:

No data

Nominal and measured concentrations:

No data

Details on test conditions:

TEST SYSTEM
- Ten replicates of Ceriodaphnia were placed in each snap cap of 30 ml size to prevent a shortage of dissolved oxygen.
- Renewal rate of test solution: The solutions were replaced every 48 h and the concentration before and after the replacement was analyzed using the HPLC.

EFFECT PARAMETERS MEASURED
The survival and the number of neonates was counted for eight days, when most of the Ceriodaphnia had finished delivering three broods. Only the numbers of first three broods were counted and compared with the blanks.

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Duration:

8 d

Dose descriptor:

NOEC

Effect conc.:

1.07 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

other: survival and the number of neonates was counted for 8 days

Any other information on results incl. tables

None

Applicant's summary and conclusion

Validity criteria fulfilled:

not specified

Conclusions:

The 8-day NOEC was determined to be 1070 µg/L for the reproduction and for the survival of the adult test animals, respectively.

Executive summary:

The three-brood reproduction test was conducted to evaluate the influence of the test item on the survival and reproduction of daphnids (Ceriodaphnia dubia).

Ten replicates of Ceriodaphnia were placed in each snap cap of 30 mL size to prevent a shortage of dissolved oxygen. Five concentrations and blanks were prepared with dechlorinated tap water, and the survival and the number of neonates was counted for eight days, when most of the Ceriodaphnia had finished delivering three broods. The solutions were replaced every 48 h (i.e. a semi-static system) and the concentration before and after the replacement was analyzed using the HPLC. Only the numbers of first three broods were counted and compared with the blanks. Multiple comparisons were conducted to determine NOEC values. The geometrical mean of the measured concentration of the selected antimicrobials was used for the determination of NOEC.

The 8-day NOEC was determined to be 1.07 mg/L for the reproduction and for the survival of the adult test animals, respectively.