Reaction mass of 2,2'-(vinylenedi-p-phenylene)bis[5-methylbenzoxazole] and 2,2'-(vinylenedi-p- phenylene)bisbenzoxazole and 2-[4-[2-[4-(benzoxazol-2- yl)phenyl]vinyl]phenyl]-5-methylbenzoxazole

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-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:

guideline study with acceptable restrictions

Remarks:

The study was conducted in accordance with SN EN 45001.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

adopled 4 April 1984

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

no

Analytical monitoring:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna (Straus, 1820).
- Breeding: parental and young Daphnia were held in 250 litres glass aquaria.
- Food type: sera micropan (sera GmbH, D-52525 Heinsberg) homogenized in 1 litre deionized water.
- Amount: 15 g
- Frequency: once a day, except weekends.
- Size: < 2 mm

ACCLIMATION
- Acclimation period: daphnia were acclimatized to the reconstituted water for 4 hours before introduction into the test media.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test temperature:

20 ± 0.5 °C (temperature-controlled water bath)

pH:

Test vessels: 7.9 start and 7.9 at 48 hrs
Control: 7.9 start and 7.7 at 48 hrs

Dissolved oxygen:

Test vessels: 7.3 mg/l start and 6.8 mg/l at 48 hrs
Control: 6.7 mg/l start and 6.8 mg/l at 48 hrs

Nominal and measured concentrations:

100 mg/l nominal

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 ml flasks, all-glass, with 50 ml of test medium.
- Volume: flasks with 50 ml of test medium.
- Aeration: not aerated
- No. of organisms per concentration: 40 individuals per test concentration.
- No. of organisms per vessel: 20 individuals per vessel.
- No. of vessels per concentration: 2 replicates.
- No. of vessels per control: 3 replicates.

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted water (lSO 6341)
- Aeration: prior to the test, a batch of reconstituted water was aerated vigorously over a period of 2 hours.

OTHER TEST CONDITIONS
- Adjustment of pH: pH was not adjusted before the test.
- Photoperiod: 16 h photoperiod a day, supplied by overhead white fluorescent tubes.

EFFECT PARAMETERS MEASURED
The median effective concentration (EC50 value) is the concentration estimated to immobilize 50 % of the Daphnia atter 24 or 48 h of exposure. Those individuals not able to swim within 15 s after gentle agitation of the test vessel were considered to be immobile.

RANGE-FINDING STUDY
No range finding test was conducted.

VALIDITY
The test is considered valid if not more than 10 % of Ihe Daphnia in the control have been immobilized or trapped at the surface of the water. The dissolved oxygen concentration at the end of the test should not be < 60 % of the air saturation value at the temperature used.

Reference substance (positive control):

yes

Remarks:

periodically conducted reference test with potassium dichromate

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

At the nominal concentration of 100 mg/l less than 10 % of the Daphnia were immobile after 24 and 48 h of exposure.
The no-observed-effect concentration (EC0) for 24 and 48 h of incubation resulted to be less than 100 mg/l. 100 % immobilization was not detected.

CONTROL
No toxic effects (less than 10 % immobilization) were observed in the control after 24 and 48 h of exposure.

Immobilization of Daphnia magna after 24 and 48 h of exposure to the test material

Nominal concentration (mg/l)	Vessel	no. of individuals	Immobile daphnia (no./vessel)		% immobile daphnia
			24 hrs	48 hrs	24 hrs	48 hrs
Control	A	20	0	0	0	0
	B	20	0	0	0	0
	C	20	0	0	0	0
100	A	20	0	1	0	5
	B	20	0	2	0	10

pH-values and oxygen concentrations at the start and at the end of the test

Nominal concentration (mg/l)	Vessel	pH value		Oxygen concentration (mg/l)
		0 hrs	48 hrs	0 hrs	48 hrs
Control	A	7.9	7.7	6.7	6.8
	B
	C
100	A	7.9	7.9	7.3	6.8
	B

Validity criteria fulfilled:

yes

Remarks:

not more than 10 % of daphnids in the control have been immobilized and the dissolved oxygen concentration at the end of the test was higher than 60 % of the air saturation value at the temperature used.

Conclusions:

EC50 (48h) > 100 mg/l (nominal)

Executive summary:

The acute toxicity of test item to Daphnia magna was investigated under static exposure conditions over a period of 48 h. The only applied test concentration was 100 mg/l nominal concentration. 40 individual Daphnia divided in 2 test vessels were exposed to the test substance. The final test concentration was prepared by dilution of a stock solution of the test substance. No chemical analysis of the test media was conducted. For the valuation of the test, the nominal content of the test solution was used, assuming the test compound to be stable in water over 48 h.

At the nominal concentration of 100 mg/l less than 10 % of the Daphnia were immobile after 24 and 48 h of exposure. No toxic effects (less than 10 % immobilization) were observed in the control after 24 and 48 h of exposure.

Conclusion

EC50 (48h) > 100 mg/l (nominal)

Description of key information

Not harmful/toxic to aquatic invertebrates, after short-term exposure.

Additional information

The acute toxicity of Fluorescent Brightener 219 to Daphnia magna was investigated under static exposure conditions, over a period of 48 h. The only applied test concentration was 100 mg/l nominal concentration; the final test concentration was prepared by dilution of a stock solution of the test substance. No chemical analysis of the test media was conducted. At the nominal concentration assayed less than 10 % of the Daphnia were immobile after 24 and 48 hours of exposure.

In order to support the study outcomes, available data on one of the substance constituents (i.e. constituent 02) have also been taken into conderation.

The acute toxicity of the substance to Daphnia magna was investigated under static exposure conditions over a period of 48 h. A screening test with nominal concentrations of 100, 10 and 1 mg/l was performed. Due to the limited water solubility of the test material, test item in concentrations of 1, 10 and 100 mg/l was moderately stirred in Daphnia medium for 24 h at room temperature. After this incubation time, the undissolved materials were removed by filtration. The resulting water accomodated fractions were used in the tests. No chemical analysis of the test media was conducted. At all loading rates no significant effects (<10 % immobilization) were observed after 24 and 48 h of exposure. No significant toxic effects were also observed in the control after 24 and 48 hours of exposure.

In both the cases, no acute adverse effects were recorded at the highest tested dosages; thus, the substance resulted to be not harmful/toxic to aquatic invertebrates, after short-term exposure.