Benzene

Toxicity to other aquatic organisms

Administrative data

Endpoint:

toxicity to other aquatic vertebrates

Type of information:

experimental study

Adequacy of study:

disregarded due to major methodological deficiencies

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: non-GLP, near gudieline study, available as unpublished report, discounted from EU RAR

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1982

Report date:

1982

Materials and methods

Principles of method if other than guideline:

A flow through system was used to expose fertilised leopard frog eggs to bezene at four test concentrations from within 30 minutes of fertilisation to four days post hatch. Test concentrations were confirmed with analytical monitoring. Mortality and teratology was monitored daily.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Benzene

EC Number:

200-753-7

EC Name:

Benzene

Cas Number:

71-43-2

Molecular formula:

C6H6

IUPAC Name:

benzene

Details on test material:

reagant grade

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material :
not applicable

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

daily sampling

Test solutions

Vehicle:

no

Details on test solutions:

Benzene was added to diluent water and stirred continuously with a magnetic stirrer to produce a stock solution. This was added to the flow through system via a graduated syringe pump to produce the required test concentrations.

Test organisms

Test organisms (species):

Rana pipiens

Details on test organisms:

Obtained from Nasco, Oshkosh, Winconsin, USA. Eggs were induced with pituatory extract.

Study design

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Remarks on exposure duration:

fertilisation to 4 days post hatch

Post exposure observation period:

none

Test conditions

Hardness:

96.6 +/- 1mg/l CaCO3

Test temperature:

20.2 +/- 0.5°C

pH:

7.7+/-0.02

Dissolved oxygen:

7.5+/-0.1

Salinity:

not applicable

Nominal and measured concentrations:

Authors state that toxicant monitoring data indicated good reproducibility of exposure concentrations. Results are reported for test concentrations of 0.016, 0.048, 0.61, 2.99 and 5.07mg/l but it is unclear whether these are nominal or measured.

Details on test conditions:

Fertilised eggs were exposed in a closed, temperature controlled, flow through system with no headspace. 50-125 eggs were exposed at each test concentration on a inlet screen. Eggs were examined daily and dead specimens removed. Exposure continued until 4 days post hatch.

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Dose descriptor:

LC50

Effect conc.:

4.03 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: at hatching

Effect concentrations 2

Dose descriptor:

LC50

Effect conc.:

3.66 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 4 days post hatching

Effect concentrations 3

Dose descriptor:

LC10

Effect conc.:

75.6 µg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 4 days post hatching

Effect concentrations 4

Dose descriptor:

other: LC1

Effect conc.:

3.2 µg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 4 days post hatching

Details on results:

data not reported

Results with reference substance (positive control):

not applicable

Reported statistics and error estimates:

data not reported

Applicant's summary and conclusion

Validity criteria fulfilled:

not specified

Conclusions:

The LC1 from a leopard frog early life stage test is 3.2ug/l

Executive summary:

This study exposed fertilised leopard frog eggs to benzene in a closed flow through system. Analytical monitoring was used to confirm exposure concentrations. This study was excluded from the EU RAR for benzene (2002) as the results reported were much lower than those found by other authors.