α,α,α',α'-tetramethyl-m-xylene-α,α'-diol

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: - Not enough details on test organism (source, feeding). - Chemical analyses were not performed according to OECD guideline 211.

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Deviations:

yes

Remarks:

- Not enough details on test organism (source, feeding). - Chemical analyses were not performed according to OECD guideline 211.

GLP compliance:

yes

Remarks:

GLP issued by State Environmental Protection Administration (SEPA) of the People’s Republic of China

Analytical monitoring:

yes

Details on sampling:

All test solutions were taken from all test solutions at the beginning (0 d), immediately prior to the first renewal of the test solution (3 d) and weekly thereafter (9, 21 d). The highest and lowest test conditions were analyzed. Water samples collected were filtrated by 0.22 µm membrane and then analysed by UPLC-PDA mentioned above.

Remark from the reviewer: One interval should be sampled and analyzed each week according to OECD protocol.

Vehicle:

no

Details on test solutions:

Stock solution I (100.0 mg/L): adding 0.010g test substance in to 100mL pure water, ultrasonicating for 30 min.
Stock solution II (10.0 mg/L): diluting 10.0 mL stock solution I with test water, making up to 100 mL.
The test solutions were prepared by diluting the stock solution with test water.

Test organisms (species):

Daphnia magna

Details on test organisms:

Daphnia magna, not being the first brood progeny, was the test species which were 6 to 24 hours old at the start of the test. All organisms used for a particular test originated from cultures established from the same healthy stock of daphnia. The stock animals were maintained in culture conditions (light, temperature, and medium) similar to those to be used in the test.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Hardness:

119 to 124 mg (CaCO3)/L

Test temperature:

20to 21 °C

pH:

7.4 to 7.6

Dissolved oxygen:

90% to 101% of the air saturation

Nominal and measured concentrations:

Nominal: 0.10, 0.20, 0.40, 0.80, 1.60 mg/L
Measured; 0.10 - 0.12 mg/l, 1.60 - 1.60 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 100-mL glass beakers
- Aeration: no
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10
- Light: 16-hour light and 8-hour dark cycle daily, light intensity: 1000 to 1500 lux

TEST MEDIUM
Good quality tap water which had been dechlorinated for at least 24 h was used. The total hardness of the test water was 122.2 mg (CaCO3)/L, oxygen concentration was about 98% of the air saturation value and pH was 7.55 at room temperature. Characteristics of the dilution water are measured at least twice a year by Jiangsu Provincial Center for Disease Prevention and Control.

Reference substance (positive control):

not specified

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 1.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 1.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: parent mortality

Details on results:

During the test, all animals in the control were alive and the mean number of live offspring produced per parent animal surviving at the end of the test was > 60. The coefficient of variation around the mean number of living offspring produced per parent animal in the control(s) was ≤ 25%.
Throughout the test period, no dead adults were observed in 0.10, 0.20, 0.40 and 1.60 mg/L treatments. One adult died in the 0.80 mg/L treatment at the end of test.

Reported statistics and error estimates:

For the estimation of the lowest observed effect concentration (LOEC), and hence the no observed effect concentration (NOEC), for effects of the chemical on growth rate, the mean growth rate for each concentration were compared with the control mean using a multiple comparison method of Dunnett’s tests (ANOVA SPSS 17.0).

Validity criteria fulfilled:

yes

Conclusions:

The study was performed under Chinese GLP. The study can be used for risk assessment and classification and labelling, with some restrictions.

Executive summary:

Under semi-static conditions of 72 h-renewal, the effect on the reproductive output of Daphnia magna exposed to the test substance (meta-Diisopropanolbenzene) for 21 days was conducted according to the following guidelines: “The guidelines for the testing of chemicals”, SEPA(HJ/T 153 -2004); Procedure 204 of the Daphnia magna, Reproduction Test”, OECD Guidelines for Testing of Chemicals, 211, adopted on 21 September 1998.etc.

During the whole test period, the pH values of the control mediums and Test Media were between 7.5 and 7.9, and the Dissolved Oxygen (DO) values varied from 90% to 98% of the air saturation at the test temperature, the hardness values varied from 119 to 121 mg(CaCO₃)/L, and the temperature of the Test Media was maintained in the range of 20^oC to 21^oC. All animals in the control were alive and the mean number of live offspring produced per parent animal surviving at the end of the test was > 60. The coefficient of variation around the mean number of living offspring produced per parent animal in the control(s) was ≤25%. So the study met the acceptability criteria. Therefore the test was considered valid.

In order to confirm the stability of the test item in the test medium, concentrations of the test samples during thetest were analyzed by UPLC-PDA. A linear regression equation was obtained with the mean peak squares(A) vs. the concentration of the testsubstance (c, mg/L): A =c-1220.4, with good linearity of r²=0.999. The results show that linearity for the concentration range of 0.10 mg/L to 2.00 mg/L is good. Besides, the minimum detection amount of UPLC-PDA for the test substance is 5.0×10^-10g, and the minimum detection concentration for water sample is 0.10mg/L. The analytical results showed that the concentration of the test substance is consistent in the test medium throughout the test period (deviation within 20% of the initial concentration). Thus a semi-static method of 72h-renewal test procedure was reasonable.

The results showed that under valid semi-static test conditions (72 h-renewal), the LOEC is greater than 1.60 mg/L (measured concentration 1.60 mg/L). The NOEC is 1.60 mg/L (measured concentration 1.60 mg/L). According to“The guidelines for the hazard evaluation of new chemical substances (HJ/T 154 -2004)”, belongs to low toxic chemical for Daphnia magna.

Description of key information

The results showed that under valid semi-static test conditions (72 h-renewal), the LOEC is greater than 1.60 mg/L (measured concentration 1.60 mg/L). The NOEC is 1.60 mg/L (measured concentration 1.60 mg/L).