Diphenyl carbonate

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

GLP compliance:

no

Analytical monitoring:

no

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

21.3 ± 0.45 °C

pH:

7.9 ± 0.2

Dissolved oxygen:

oxygen concentration varied between 8.4 and 9.7 mg/L during the tests

Nominal and measured concentrations:

nominal concentrations: 3.16, 10.0, 31.6 mg/L
geometric mean over time: 0.91, 2.9, 5.6 mg/L (assuming a half-life of about 40 h and a water solubility of about 13 mg/L)

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

3.16 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

31.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: ; geometric mean

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

0.91 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: Estimation based on half-life of 40 hours

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

5.6 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: Estimation based on half-life of 40 hours

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

3.9 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: Estimation based on half-life of 40 hours, graphic interpolation (linear); geometric mean

Sublethal observations / clinical signs:

Due to the hydrolysis of diphenyl carbonate in the presence of water, forming phenol and carbon dioxide, the effective concentrations of diphenyl carbonate are estimated for each test concentration. With the assumption that the half-life of diphenyl carbonate is about 40 hours under abiotic conditions in a buffered medium, and a water solubility of 13 mg/l, the geometric mean over time (inclusive 24 hours of stirring before the test) is 5.6 mg/l, 2.9 mg/l and 0.91 mg/l at the nominal test concentrations of 31.6 mg/l, 10 mg/l and 3.16 mg/l. By graphic interpolation (linear) the resulting effective 96 h LC50 is 3.9 mg/l.

Conclusions:

Under the conditions of the study, the 96-hour LC50 was determined to be 3.9 mg/L.

Executive summary:

The key study was conducted according to the standardised guideline EU Method C.1.

During the study, Danio rerio were exposed to the test material at nominal concentrations of 3.16, 10.0 and 31.6 mg/L. This study utilised a static test system in freshwater with a total exposure time of 96 hours with 10 fish per concentration of test material. Due to the hydrolysis of diphenyl carbonate in the presence of water, forming phenol and carbon dioxide, the effective concentrations of diphenyl carbonate were estimated for each test concentration. With the assumption that the half-life of diphenyl carbonate is about 40 hours under abiotic conditions in a buffered medium and a water solubility of 13 mg/L, the geometric mean over time (inclusive 24 hours of stirring before the test) is 5.6, 2.9 and 0.91 mg/L at the nominal test concentrations of 31.6, 10 and 3.16 mg/L, respectively. The resulting effective 96 h LC50 was determined by graphic interpolation (linear).

In Danio rerio a LC0 of 3.16 mg/L and a LC100 of 31.6 mg/L after 96 h were obtained. The effective 96 h LC50 is 3.9 mg/L.

Description of key information

The toxicity of diphenyl carbonate to fish (Danio rerio) was assessed according to EU Method C.1 (Bayer, 1994). The effective concentrations LC0 and LC100 were determined to 0.91 and 5.6 mg/L, respectively (geometric mean over time). By graphic interpolation (linear) the resulting 96 h LC50 was determined to 3.9 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

3.9 mg/L

Additional information

As agreed in the OECD ICCA/HPV-program, a half-life of 39.9 hours and a water solubility of 13 mg/L were used for the interpretation of aquatic data. The nominal diphenyl carbonate concentrations were converted to effective concentrations by approximation as geometric means over time. It is considered that the observed effects cover both the toxicity of diphenyl carbonate and the toxicity of the degradation products.

 

Short-term toxicity to fish

This endpoint is addressed with 5 studies; one key study and four additional studies of varying reliability.

 

The key study was conducted according to the standardised guideline EU Method C.1 (Bayer, 1994) and was awarded a reliability score of 2 in accordance with the criteria for assessing data quality as set forth by Klimisch et al. (1997).

Danio rerio were exposed to the test material at nominal concentrations of 3.16, 10.0 and 31.6 mg/L. This study utilised a static test system in freshwater with a total exposure time of 96 hours with 10 fish per concentration of test material. Due to the hydrolysis of diphenyl carbonate in the presence of water, forming phenol and carbon dioxide, the effective concentrations of diphenyl carbonate were estimated for each test concentration. With the assumption that the half-life of diphenyl carbonate is about 40 hours under abiotic conditions in a buffered medium and a water solubility of 13 mg/L, the geometric mean over time (inclusive 24 hours of stirring before the test) is 5.6, 2.9 and 0.91 mg/L at the nominal test concentrations of 31.6, 10 and 3.16 mg/L, respectively. The resulting effective 96 h LC50 was determined by graphic interpolation (linear).

In Danio rerio a LC0 of 3.16 mg/L and a LC100 of 31.6 mg/L after 96 h were obtained. The effective 96 h LC50 is 3.9 mg/L.

 

The first supporting study (Applegate, 1957) has been awarded a reliability score of 4 in accordance with the criteria for assessing data quality as set forth by Klimisch et al. (1997) due to the documentation being insufficient for assessment.

Salmo gairdneri, Lepomis macrochirus and Petromyzon marinus were exposed to the test material. A static test system was implemented over a total of 24 hours. The effects were observed at 15 minute test durations. The time necessary to produce death or obvious distress of the fish was determined. In this case only illness of the test species was observed.

The NOEC for Salmo gairdneri and Lepomis macrochirus was identified as < 5 mg/L. The LC0 for Petromyzon marinus was determined to be 5 mg/L after 24 hours.

 

The second supporting study (MacPhee, 1969) has also been awarded a reliability score of 4 in accordance with the criteria for assessing data quality as set forth by Klimisch et al. (1997) due to the documentation being insufficient for assessment.

Ptychocheilus oregonensis (northern squawfish), Oncorhynchus tshawytscha (chinook salmon) and Oncorhynchus kisutch (coho salmon) were exposed to the test material for 24 hours. One fish of each species was tested. The study incorporated a static and aerated test system and used freshwater. The concentration of the test system was measured once and found to be 10 mg/L.

The test criteria are the exposure time at which loss-of-equilibrium and death occurred. Loss-of-equilibrium time was reported as E, with D being used for death time. The lower limit of the range reported indicates the time that the last observation was made before loss-of-equilibrium or death; the upper limit indicates the time that loss-of-equilibrium or death was noted.

In Squawfish the E-value was 1 to 2 hours and the D-value 7.5 to 13 hours. In Chinook salmon and the Coho salmon the E-value was 1 to 2 hours and the D-value: 2 to 4 hours.

 

The third supporting study (Bayer, 1979) was awarded a reliability score of 3 in accordance with the criteria for assessing data quality as set forth by Klimisch et al. (1997) due to having significant methodological deficiencies; the test was carried out with only two fish per concentration.

Leuciscus idus were exposed to the test material in two ways; a 20 hour test at a concentration of 500 mg/L and a 72 hour test at a concentration of 200 mg/L were conducted. At the nominal concentration of 500 mg/L, both fish were dead after 20 hours. In the 20 hour test, the LC100 was therefore identified to be 500 mg/L. In the 72 hour test, The LC0 was identified as 200 mg/L.

 

The final supporting study (Loeb, 1963) was also awarded a reliability score of 3 in accordance with the criteria for assessing data quality as set forth by Klimisch et al. (1997). Unsuitable methodology was followed for this test; the method employed was an acute oral toxicity test and the results are not reliable as the exposure pathway is via oral uptake and no through waterborne exposure.

A method for force-feeding was developed in which Cyprinus carpio were immobilised in a nose-up position by a specially constructed device employing foam rubber jaw and activated by compressed air. The basic objective was to discover compounds that were lethal at low doses of 30 mg or less per kg of body weight. The test material was administered to the fish within gelatin capsules. During the observation period, if a fish was considered to look abnormal or to be exhibiting abnormal behaviour, it was considered to be sick. If no movement occurred it was recorded as dead.

The LC0 was identified as 122 to 215 mg/kg bw, over a 5 day test period.