p-phenylbenzaldehyde

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:

1999-01-12 to 1999-01-16

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: An amount of test material (300 mg) was dissolved in dimethylformamide and the volume adjusted to 10 mL to give a 300 mg/10 mL solvent stock solution. An aliquot of this solvent stock solution (2.0 mL) was dispensed into 20 litres of dechlorinated tap water to give the 3.0 mg/L test concentration.

- Sampling method: The concentration and stability of the test material in the test solutions were verified by chemical analysis at 0 (freshly prepared test media), 24, 48, 72 (freshly prepared test media and prior to each test media renewal) and 96 hours ( on termination of the study after 96-h).

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: the test material was prepared using a preliminary solution in dimethylformamide. An amount of test material (300 mg) was dissolved in dimethylformamide and the volume adjusted to 10 mL to give a 300 mg/10 mL solvent stock solution. An aliquot of this solvent stock solution (2.0 mL) was dispensed into 20 litres of dechlorinated tap water to give the 3.0 mg/L test concentration. The concentration and stability of the test material in the test solutions were verified by chemical analysis at 0 (fresh media), 24, 48, 72 (fresh and old media) and 96 hours (old media). Samples taken on each occasion were analysed prior to and after filtration

Test organisms (species):

Leuciscus idus

Details on test organisms:

TEST ORGANISM
- Common name: Golden Orfe
- Strain: Not applicable
- Source: Xotic Fish Centre, Alfreton, Derbyshire, UK
- Age at study initiation: not specified
- Length at study initiation: 5.1 cm (sd = 0.3)
- Weight at study initiation: 1.30 g (sd = 0.16)

ACCLIMATION
- Acclimation period: two weeks
- Acclimation conditions: same as test
- Type and amount of food during acclimation: Tetramin® flake food
- Feeding frequency during acclimation: ad libithum
- Health during acclimation: There was zero mortality in the 7 days prior to the start of the test

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

100 mg/L as CaCO3

Test temperature:

21 ± 0.5 °C

pH:

7.4 to 7.6

Dissolved oxygen:

7.5 – 8.8 mg O2/L

Nominal and measured concentrations:

Nominal concentration: 3.0 mg/L
Measured concentration: measured test concentrations of 97% to 122% of nominal for the unfiltered test media and concentrations of 69% to 84% for the filtered test media

Details on test conditions:

TEST SYSTEM
- Test vessel: glass exposure vessels
- Type: closed
- Material, size: glass, 20 L
- Aeration: yes
- Renewal rate of test solution: daily
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The test water used for both the range-finding and definitive studies was the same as that used to maintain the stock fish. Laboratory tap water dechlorinated by passage through an activated carbon filter (Purite Series 500) and partly softened (Elga Nimbus 1248D Duplex Water Softener) giving water with a total hardness of approximately 100 mg/l as CaC03. After dechlorination and softening the water was then passed through a series of computer controlled plate heat exchangers to achieve the required temperature.
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours light and 8 hours darkness

EFFECT PARAMETERS MEASURED: An estimate of the LC50 values was given by inspection of the mortality data.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: none
- Range finding study: yes
- Test concentrations: 3 mg/L
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 0.98 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

0.98 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

The test concentration of 3.0 mg/L was the highest attainable test concentration due to the limited solubility of the test material in water and auxiliary solvents, and having due regard for the amount of auxiliary solvent permitted in the test under the OECD Guidelines.

Sublethal observations / clinical signs:

Range-finding study

The results showed no mortalities at all the test concentrations employed during the range-finding study: During preliminary solubility work precipitation of test material was observed (by visual inspection) at concentrations in excess of 3.0 mg/L indicating this to be the maximum limit of water solubility under these test conditions.

Based on this information, a single test concentration, in duplicate, of 3.0 mg/L was selected for the definitive study. This experimental design conforms to a "Limit test" to confirm that at the highest attainable test concentration of 3.0 mg/L, no mortalities or sub-lethal effects of exposure were observed.

 

 

Table 1: Cumulative Mortality Data in the Range-Finding Study

 

Concentration (mg/L)	Cumulative mortality (initial population = 3)
	24 hours	48 hours	72 hours	96 hours
Control	0	0	0	0
Solvent control	0	0	0	0
0.10	0	0	0	0
1.0	0	0	0	0
3.0	0	0	0	0

 

 

Pre-study dosing trial

A pre-study dosing trial was carried out in order to determine whether dynamic, continuous flow test conditions were practical. Observations made after dosing for 48 hours showed a precipitate of test material to be present within the dosing system. Based on this information the use of dynamic, continuous flow test conditions was considered to be inappropriate. Therefore a semi-static test regime was selected for the definitive study.

 

 

Definitive study

Mortality data

There were no mortalities in 20 fish exposed to a test concentration of 3.0 mg/L for a period of 96 hours. Inspection of the mortality data gave the following results:

 

Table 2: Mortality data

 

Time (h)	LC50  (mg/L)	95 % Confidence limits (mg/L)
3	>3.0	-
6	>3.0	-
24	>3.0	-
48	>3.0	-
72	>3.0	-
96	>3.0	-

 

However, the final results at all-time points are based on the time weighted mean measured concentration of the filtered test media, i.e. all values of > 3.0 mg/L are replaced by > 0.98 mg/L (for explanation see executive summary).

 

Table 3: Cumulative Mortality Data in the Definitive Study

 

Nominal concentration (mg/L)	Cumulative mortality (initial population = 10)						% mortality
	3 hours	6 hours	24 hours	48 hours	72 hours	96 hours	96 hours
Control	0	0	0	0	0	0	0
Solvent control	0	0	0	0	0	0	0
3.0 R,	0	0	0	0	0	0	0
3.0 R2	0	0	0	0	0	0	0

R₁ - R₂ = Replicates 1 - 2

The results of the definitive study showed the highest test concentration resulting in 0 % mortality to be greater than or equal to 3.0 mg/L, the lowest test concentration resulting in 100% mortality to be greater than 3.0 mg/L and the No Observed Effect Concentration (NOEC) to be 3.0 mg/L. The No Observed Effect Concentration is based upon zero mortalities and the absence of any sub-lethal effects of exposure at this concentration.

Validity criteria fulfilled:

yes

Conclusions:

The acute toxicity of the test material to the freshwater fish golden orfe (Leuciscus idus) has been investigated and based on measured concentrations gave a 96-Hour LC50 of greater than 0.98 mg/L. Correspondingly the No Observed Effect Concentration was equal to 0.98 mg/L.

Executive summary:

A study was performed to assess the acute toxicity of the test material to golden orfe (Leuciscus idus). The method followed that described in the OECD TG 203 and Method C.1 under GLP. For this purpose, fish were exposed, in two groups of ten, to an aqueous dispersion of the test material, at a single concentration of 3.0 mg/L for a period of 96 hours under semi-static test conditions. The number of mortalities and any sub-lethal effects of exposure in each test and control vessel were determined 3 and 6 hours after the start of exposure and then daily throughout the study until termination after 96 hours.

The test concentration of 3.0 mg/L was the highest attainable test concentration due to the limited solubility of the test material in water and auxiliary solvents, and having due regard for the amount of auxiliary solvent permitted in the test under the OECD Guidelines.

During the preliminary solubility and range-finding work it was difficult to determine whether all of the test material had dissolved in the test medium (by visual inspection) or whether a micro-dispersion may have formed. Pre-study samples approximately equivalent to the test concentration to be used in the definitive study were analysed directly and after filtration through 0.2 µm membrane filters. The results indicated a slight loss of test material from the filtered sample. Therefore analysis was performed on samples of filtered and unfiltered test media during the definitive study.

Analysis of the fresh test media sampled at 0, 24, 48 and 72 hours showed measured values of 97 % to 122 % of nominal for the unfiltered test media and 69 % to 84 % for the filtered test media. However, a marked decline was shown for the old or expired test media, sampled at 24, 48, 72 and 96 hours, with measured values of 7 % to 32 % of nominal for the unfiltered test media and 2 % to 19 % for the filtered test media. This marked decline was considered to be due to instability of the test material in the diluent and possible bioaccumulation in the tissues of the test fish.

The 96-Hour LC₅₀ for the test material to golden orfe (Leuciscus idus), based on nominal test concentrations was determined to be greater than 3.0 mg/L and correspondingly the No Observed Effect Concentration (NOEC) was equal to 3.0 mg/L.

The measured concentrations of the unfiltered test samples indicate the amount of test material which is both dispersed and dissolved in the test system, whereas the filtered test samples indicate the amount of test material in solution and thus bioavailable to the test fish.

Given the above results, it was considered justifiable to express the results based on the time-weighted mean measured concentration of the filtered test media. Therefore, the 96-Hour LC₅₀ was greater than 0.98 mg/L and correspondingly the No Observed Effect Concentration (NOEC) was equal to 0.98 mg/L.

Description of key information

The acute toxicity of the test material to the freshwater fish golden orfe (Leuciscus idus) has been investigated and based on the measured concentrations gave a 96-Hour LC₅₀ of greater than 0.98 g/L. Correspondingly the No Observed Effect Concentration was equal to 0.98 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

0.98 mg/L

Additional information

A study was performed to assess the acute toxicity of the test material to golden orfe (Leuciscus idus). The method followed that described in the OECD TG 203 and Method C.1 under GLP. For this purpose, fish were exposed, in two groups of ten, to an aqueous dispersion of the test material, at a single concentration of 3.0 mg/L for a period of 96 hours under semi-static test conditions. The number of mortalities and any sub-lethal effects of exposure in each test and control vessel were determined 3 and 6 hours after the start of exposure and then daily throughout the study until termination after 96 hours.

The test concentration of 3.0 mg/L was the highest attainable test concentration due to the limited solubility of the test material in water and auxiliary solvents, and having due regard for the amount of auxiliary solvent permitted in the test under the OECD Guidelines.

During the preliminary solubility and range-finding work it was difficult to determine whether all of the test material had dissolved in the test medium (by visual inspection) or whether a micro-dispersion may have formed. Pre-study samples approximately equivalent to the test concentration to be used in the definitive study were analysed directly and after filtration through 0.2 µm membrane filters. The results indicated a slight loss of test material from the filtered sample. Therefore analysis was performed on samples of filtered and unfiltered test media during the definitive study.

Analysis of the fresh test media sampled at 0, 24, 48 and 72 hours showed measured values of 97 % to 122 % of nominal for the unfiltered test media and 69 % to 84 % for the filtered test media. However, a marked decline was shown for the old or expired test media, sampled at 24, 48, 72 and 96 hours, with measured values of 7 % to 32 % of nominal for the unfiltered test media and 2 % to 19 % for the filtered test media. This marked decline was considered to be due to instability of the test material in the diluent and possible bioaccumulation in the tissues of the test fish.

The 96-Hour LC₅₀ for the test material to golden orfe (Leuciscus idus), based on nominal test concentrations was determined to be greater than 3.0 mg/L and correspondingly the No Observed Effect Concentration (NOEC) was equal to 3.0 mg/L.

The measured concentrations of the unfiltered test samples indicate the amount of test material which is both dispersed and dissolved in the test system, whereas the filtered test samples indicate the amount of test material in solution and thus bioavailable to the test fish.

Given the above results, it was considered justifiable to express the results based on the time-weighted mean measured concentration of the filtered test media. Therefore, the 96-Hour LC₅₀ was greater than 0.98 mg/L and correspondingly the No Observed Effect Concentration (NOEC) was equal to 0.98 mg/L.