4,4'-oxydianiline

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: The test has been conducted according to US standardardised methods. GLP not specified and the test concentrations were not checked (but the substance is expected to be stable)

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: US. EPA. 1994. Short-term Methods for estimating the chronic toxicity of effluents and receiving waters to freshwater organisms. 3rd Ed. EPA/600/4-91/002. US. Environmental Protection Agency, Environmental Monitoring System Laboratory, Cincinnati, Ohio

Deviations:

not specified

GLP compliance:

not specified

Analytical monitoring:

no

Details on sampling:

Not applicable

Vehicle:

no

Details on test solutions:

The test material, 3,4'-oxydianiline was prepared from a sample supplied by DuPont Haskell Laboratory. The sample was shipped via courrier to EA's Aquatic Toxicology Laboratory in Sparks, Maryland. Upon receipt, the sample was logged in and assigned EA laboratory accession number AT2-519. Stocks of 3,4'-oxydianiline were prepared each day in moderately hard synthetic freshwater, and these stocks were used to dose the test solutions.

Test organisms (species):

Ceriodaphnia dubia

Details on test organisms:

Ceriodaphnia dubia (water flea) were raised in EA's culture facility using synthetic moderately hard water. the cultures were kept in an environmentally controlled room at 25°C with a 16-hour light/8-hour dark photoperiod. Organisms were fed daily with trout chow/yeat.cereal leaves solution supplemented with algae (S. capricornutum) as described in US EPA (1993) method. Gravid adults were reisolated the evening before the test to ensure that neonates were less than 24 hours old at test initiation. The neonated delected for the test were released within an 8-hour period from the time of reisolation, from broods of eight or more.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

7 d

Post exposure observation period:

Not applicable

Hardness:

no data

Test temperature:

25°C +/- 1°C

pH:

6.0 - 9.0

Dissolved oxygen:

> 4.0 mg/l

Salinity:

Not applicable

Nominal and measured concentrations:

Nominal concentrations were: 0 (control), 1.35, 3.2, 7.5, 18, 42 and 100 µg/L

Details on test conditions:

Conductivity: 338 µS/cm +/1 20 µS/cm

Reference substance (positive control):

yes

Remarks:

sodium chloride

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

immobilisation

Remarks on result:

other: Not calculable

Key result

Duration:

7 d

Dose descriptor:

NOEC

Effect conc.:

18 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: Concentration below the concentration at which a significant difference was observed from the control (p=0.01)

Duration:

7 d

Dose descriptor:

LOEC

Effect conc.:

42 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: lowest concentration with a significant difference from the control (p=0.01)

Duration:

7 d

Dose descriptor:

other: IC25

Effect conc.:

40.1 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: 95% confidence limits: 26.5 - 50.1 µg/L

Details on results:

During the test, the temperature ranged from 24.3 to 25.7 °C, the pH from 7.6 to 8.2 and the oxygen concentrations was measured from 7.3 to 8.2 mg/L.
The conductivity was measured between 291 µS/cm and 349 µS/cm.

Results with reference substance (positive control):

Results with sodium chloride as reference substance:
IC25 = 920 mg/L NaCl.
The acceptable control chart limites are 7.5 - 1207 mg/L NaCl.
Therefore, the sensitivity of the ceriodaphnia is considered as acceptable and the validity criteria is fulfilled.

Reported statistics and error estimates:

Not reported

Results with the chronic definitive test with ceriodaphnia dubia

Nominal test concentration (µg/L 3,4'-oxydianiline)	48 -h % survival	7 -d % survival	mean young production(neonates/organism +/- SD)
Control	100	100	30.0 (+/-3.4)
1.35	100	90	26.8 (+/-7.5)
3.2	100	100	24.6 (+/-3.4)
7.5	100	100	26.7 (+/-4.2)
18	100	100	26.9 (+/-4.5)
42	100	90	22.2 (+/-5.5)
100	100	100	4.0 (+/-2.5)

Validity criteria fulfilled:

not specified

Remarks:

sensitivity of the organism is controlled with a reference substance and the results are within the acceptable range concentrations

Conclusions:

The result with 3,4-oxydianiline reproduction toxicity test with Ceriodaphnia dubia could be used for the long term toxicity to aquatic invertebrates: NOEC = 18 µg/L (p=0.01). Therefore, 3,4'-oxydianiline could be considered as very toxic to aquatic invertebrates.

Executive summary:

A chronic toxicity test was conducted with Ceriodaphnia dubia according to US EPA guideline. A preliminary range finding test was performed to define test concentrations in the final test where no significant mortality is obtained (see results in short term toxicity to aqautic invertebrates, McCulloch, 2002). Then the final nominal test concentrations were determined from 1.35 to 100 µg/L in the final reproduction test.

No significant mortality was observed at all these concentrations in the final reproduction test whereas a significant decrease in reproduction (number of neonates/organism) was observed from 42 µg/L (p=0.01). Then the NOEC could be determined at 18 µg/L. An US EPA Guidance (2000) was used for the statistical interpretation of the results and the determination of the alpha level.

Description of key information

A chronic toxicity test was conducted with Ceriodaphnia dubia according to US EPA guideline on the analogue 3,4'-oxydianiline. A preliminary range finding test was performed to define test concentrations in the final test. Then the nominal test concentrations were determined from 1.35 to 100 µg/L in the final reproduction test.

No significant mortality was observed at all these concentrations in the final reproduction test whereas a significant decrease in reproduction (number of neonates/organism) was observed from 42 µg/L (p=0.01). Then the NOEC could be determined at 18 µg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

18 µg/L