Reaction mass of butyl diphenyl phosphate and dibutyl phenyl phosphate and tributyl phosphate

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study carried out according to guideline and under GLP

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

The fish were fed ZM wheat germ pellets instead of commercial carp pellets. Fish were exposed to the water accomodated fraction, according to OECD 2000.

Principles of method if other than guideline:

not applicable

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

no data

Vehicle:

no

Details on test solutions:

As the test material is poorly soluble, the organisms were exposed to the Water Accomodated Fraction (WAF). In this approach aquous media are prepared by mixing the test item for a prolonged period of time. At completion of the mixing and settlement the test item phase is then separated and the organisms are exposed to the aquous phase or WAF. Exposures are expressed in terms of the original concentration of the test item in water at the start of the mixing period.

Test organisms (species):

Cyprinus carpio

Details on test organisms:

The test was carried out with juvenile common carp (Cyprinus carpio), which were obtained from Rodbaston Aquaculture, Penkridge, Stafford, UK.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

not applicable

Hardness:

no data

Test temperature:

21 (+/- 1.0)°C

pH:

7.9 +/- 0.5

Dissolved oxygen:

8.9 +/- 0.5 mg/L

Salinity:

no data

Nominal and measured concentrations:

The test was carried out with nominal concentrations of: 0 (control); 0.10; 0.32; 1.0; 3.2 and 10 mg/L

Details on test conditions:

-

Reference substance (positive control):

not required

Duration:

96 h

Dose descriptor:

LL50

Effect conc.:

1.8 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CL (1.0 - 3.2 mg/L)

Duration:

96 h

Dose descriptor:

NOELR

Effect conc.:

1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: mortality or sublethal effects

Results with reference substance (positive control):

not applicable

Reported statistics and error estimates:

The 95% CL of the LL50 was 1.0 - 3.2 mg/L

Validity criteria fulfilled:

yes

Conclusions:

The 96 hr LL50 of DBPP for Cyprinus carpio was 1.8 mg/L (95% CL 1.0 - 3.2 mg/L). The NOELR for this test was 1.0 mg/L.

Executive summary:

In a test performed according to OECD guideline 203 common carp (Cyprinus carpio) was exposed to dibutyl phenyl phosphate using a Water Accomodated Fraction approach, the 96 hr LL50 of DBPP for Cyprinus carpio was shown to be 1.8 mg/L (95% CL 1.0 - 3.2). The NOELR for this test was 1.0 mg/L.

Description of key information

Short-term toxicity data (96h LC50) on 5 different fish species are available, based on 5 different studies. The most recent study (Goodband and Mullee, 2011) is regarded as key study with and LL50 (96h) of 1.8 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

1.8 mg/L

Additional information

Short-term toxicity data (96h LC50) on 5 different fish species are available, based on 4 different studies. For one additional study, the 14 -day LC50 values are available. The most recent study (Goodband and Mullee, 2011) is regarded as the key study as this study was performed according to the most recent guidelines. The LL50 value reported in this study was the lowest in comparison to the other studies. Nevertheless, all LC50 values reported in the other studies (Thompson and Forbis, 1978a and 1978b, 1979; Rice and Mastri, 1972 and Koboyashi, 2010) are in the same range of toxicity (>1 but <10 mg/L). Also the different tests with rainbow trout show very similar results. In the 14 -day test, loss of equilibrium was studied as endpoint besides mortality (Thompson and Forbis, 1979). The LC50 (14 -day) value from that study was 2.4 mg/L and the EC50 (14 -day) for loss of equilibrium was 1.2 mg/L. The 14-day LC50 is comparable in value to the 4-day LC50 (see short term effects on rainbow trout from the same authors), which indicates that the ultimate LC50 is already reached after 4 days.

Based on these results, it can be concluded that the lowest value, which is measured for common carp, is the key value for the risk assessment (LL50 (96h) = 1.8 mg/L)). Although this was measured using a WAF approach, presenting an LL50 (96h) value rather than a LC50 value it is reasonable to assume – based on the water solubility of the substance – that LL50 would be equal to the LC50 for DBPP.