2,4,6-triisopropyl-m-phenylene diisocyanate

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Non-GLP guideline study with acceptable restrictions.

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Version / remarks:

(ISO 8192-1986)

Deviations:

no

Remarks:

not reported

GLP compliance:

no

Remarks:

No public authority statement included.

Analytical monitoring:

not specified

Details on sampling:

No details are reported.

Vehicle:

no

Details on test solutions:

No details are reported.

Test organisms (species):

activated sludge

Details on inoculum:

No further details are reported.
Prepared according to ISO 8192-1986: Chapter 4.2

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

3 h

Remarks on exposure duration:

no remarks

Post exposure observation period:

No details are reported.

Hardness:

No details are reported.

Test temperature:

20.5 °C- 21.1 °C
(Control: 20.5 - 20.7)

pH:

7.4 - 7.8
(Control: 7.9)

Dissolved oxygen:

5.4 - 8.7 mg (start)
4.6 - 8.7 mg (end)

Salinity:

No details are reported.

Nominal and measured concentrations:

100, 1000 and 10000 mg/L

Details on test conditions:

No further details are reported.

Reference substance (positive control):

yes

Remarks:

3,5 Dichlorphenol

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

>= 10 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Remarks on result:

other: remark: water-insoluble

Details on results:

- 0.00 % inhibiton at quantities of 25.00 (= 100 mg/L) and 250.00 mg (=1000 mg/L)
- 11.1 % inhibiton at a quantity of 2500.00 mg (= 10000 mg/L)

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Results: 0.00 % inhibition at a quantity of 0.25 mg
66.7 % inhibition at a quantity of 5.00 mg

Reported statistics and error estimates:

No details are reported.

Table 4: Test results

		Quantity (mL/mg)	O2-Start-Value (mg)	O2-End-Value (mg)	Time (min)	Temp (°C)	pH	Inhibition (%)
1	Sludge	25.000
2	Test substance	25.000	5.80	5.20	2.0	21.1	7.8	0.00
3	Test substance	250.000	6.30	6.00	1.0	21.1	7.8	0.00
4	Test substance	2500.000	5.40	4.60	3.0	21.1	7.7	11.1
5	Reference substance	0.250	6.00	5.10	3.0	20.5	7.9	0.00
6	Reference substance	5.000	8.30	8.20	1.0	20.7	7.9	66.7
7	Control (start)	0.000	5.80	4.90	3.0	20.5	7.8	0.00
8	Control (end)	0.000	5.60	5.00	2.0	21.0	7.8	0.00
9	Autoxidation	2.500.000	8.70	8.70	10.0	21.0	7.4	0.00
EC 50 => 10000 mg/L

Validity criteria fulfilled:

yes

Remarks:

Experiment in accordance with above mentioned study method

Conclusions:

The study is regarded as a valid guideline study without GLP compliance. According to the reported results no evidence can be found that the test substance has a toxic effect to microorganisms present in activated sludge.

Executive summary:

The acute toxicity to microorganisms of the substance 2,4,6 -triisopropyl-m-phenylene diisocyanate was investigated in accordance with OECD Guideline 209 without GLP compliance (Kanne, R., 1989). Activated sludge was used in the static freshwater experiment with an exposure time to the test substance of 3 hours. The culture medium was prepared according to ISO 8192 -1986, Chapter 4.2. The temperature range was 20.5 - 21.1 °C (Control: 20.5 - 20.7 °C) and the pH was adjusted in the range of 7.4 - 7.8 (Control: 7.9). The dissolved oxygen was 5.4 - 8.7 mg at the beginning and 4.6 - 8.7 mg at the end of the experiment. The test substance was tested in the concentrations of 100, 1000 and 10000 mg/L. 3,5 -Dichlorphenol was used as reference substance and showed 66.7 % inhibition at a used quantity of 5.00 mg. Regarding the test substance an inhibition of 11.1 % was reported at a quantity of 2500 mg, which reveals a concentration of 10000 mg/L. Additionally, an EC50 (3h) value of >= 10000 mg/L is given as result, but with the remark of water insolubility.

Description of key information

Toxicity to microorganisms: EC50 (3h) >= 10000 mg/L for activated sludge (non-GLP, OECD TG 209, static)

Key value for chemical safety assessment

EC50 for microorganisms:

10 000 mg/L

Additional information

The acute toxicity to microorganisms of the substance 2,4,6-triisopropyl-m-phenylene diisocyanate was investigated in accordance with OECD Guideline 209 without GLP compliance (Kanne, 1989). Activated sludge was used in the static freshwater experiment with an exposure time to the test substance of 3 hours. The culture medium was prepared according to ISO 8192 -1986, Chapter 4.2. The temperature range was 20.5 - 21.1 °C (Control: 20.5 - 20.7 °C) and the pH was adjusted in the range of 7.4 - 7.8 (Control: 7.9). The dissolved oxygen was 5.4 - 8.7 mg at the beginning and 4.6 - 8.7 mg at the end of the experiment. The test substance was tested in the concentrations of 100, 1000 and 10000 mg/L. 3,5 -Dichlorphenol was used as reference substance and showed 66.7 % inhibition at a quantity of 5.00 mg. Regarding the test substance an inhibition of 11.1 % was reported at a quantity of 2500 mg, which reveals a concentration of 10000 mg/L. Additionally, an EC50 (3h) value of >= 10000 mg/L is reported as result, but with the remark of water insolubility.