Pyrocatechol

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 05 February 2014 to 15 May 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The study was conducted in compliance with international standard guidelines under GLP conditions.The study report was conclusive and well enough documented with all relevant information included.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

N/A

Analytical monitoring:

yes

Details on sampling:

Duplicate samples from the freshly prepared test media of all test concentrations and the controls were taken at the start of the test and at day 1.
For the determination of the stability of the test item under the test conditions and of the maintenance of the test item concentrations during the test period, duplicate samples from the aged test media of all test concentrations and the controls were collected at day 1 (after 24 hours of exposure) and at the end of the test.

For the determination of the stability of the test item under the test conditions and of the maintenance of the test item concentrations during the test period, duplicate samples from the test media of all test concentrations and the control were collected at day 1 and at the end of the test (afte 24 hours of exposure).

Vehicle:

yes

Details on test solutions:

Before test start and before the test medium renewal a concentrated stock solution (50 mg test item/L) was prepared by dissolving 0 h: 26.74 mg test item into 534.8 mL test water and 24 h: 26.91 mg test item into 538.2 mL test water by intense stirring for 10 minutes. Adequate volumes of this test medium were diluted with test water to prepare the test media. The test media were prepared just before introduction of the daphnids (= start of the test) and test medium renewal on Day 1.
The appearance of the test item in the test media was observed at the start of the test, on Day 1 in the old and the new test media and at the end of the test in the test media of all test concentrations.

Test organisms (species):

Daphnia magna

Details on test organisms:

Species: Daphnia magna (Straus), clone 5

Age at Test Start: From 4.5 to 21.5 hours old

Sex: Female

Origin: The Daphnia introduced in the test were taken from IBACON in-house laboratory culture
Breeding Conditions: The Daphnia were bred in the laboratories of IBACON under similar temperature and light conditions as used in the test. The cultivation of the parental Daphnia was performed in reconstituted water of similar quality with regards to pH, the constituent salts and total hardness as the culture medium used in the test. The test organisms were not first brood progeny. The Daphnids in the stock culture were fed at least on all working days with green algae (Desmodesmus subspicatus) freshly grown in the laboratories of IBACON.

Reference Item: For the evaluation of the quality of the Daphnia clone used and the consistency of the experimental conditions, the reference item potassium dichromate is tested at least twice a year to demonstrate satisfactory test conditions.

Acclimatisation: Was not necessary, since the test was performed in the same medium as the culturing.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

N/A

Hardness:

250 mg/L as CaCO3

Test temperature:

19 to 20 °C in the freshly prepared media;
19 to 20 °C in the aged test media

pH:

7.7 - 7.8 in the freshly prepared media;
7.5 to 7.6 in the aged test media; and thus the pH-value did not vary by more than 1.5 units

Dissolved oxygen:

8.1 to 8.8 mg/L in the freshly prepared media;
7.9 to 8.4 mg/L in the aged test media

Salinity:

N/A

Nominal and measured concentrations:

Nominal Test Concentrations: 3.35, 1.52, 0.69, 0.315, 0.143 and 0.065 mg test item/L and a control (water only) corresponding to geometric mean measured values of 2.742, 0.906, 0.326, 0.0754, 0.0443, 0.0298 mg test item/L.

Details on test conditions:

TEST UNITS:
Type and Size: Glass beakers of approximately 110 mL volume were filled completely (i.e. remaining head space reduced to a technical possible minimum of some mL) with test medium. The test vessels were covered with a conical glass stopper to reduce the loss of water due to evaporation and to avoid the entry of dust into the solutions.
Identification: Each test unit was uniquely identified with serial number, treatment and replicate number.

TEST CONDITIONS:
Test Environment: Controlled environment room
Measurement of pH, Dissolved Oxygen and Water Temperature: The water temperature, pH-values and the dissolved oxygen concentrations were determined in all freshly prepared and aged test media of each treatment group.

Light Regime: 24 h darkness
Light Intensity: The test was performed under dark conditions except of the time slot where the daphnids are observed.

Control: In the control, test water was used without addition of the test item.

Introduction of Individuals: 20 Daphnia per control and test concentration, divided into 4 groups of 5 animals, each group in 60 mL test medium
Exposure Time: 48 hours
Test Procedure: A semi-static test system with a test medium renewal on Day 1 was chosen to keep the concentrations of test item as constant as possible in the test media.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

2.55 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95 % CL: 1.69 - 2.742 mg test item/L)

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

0.326 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

LOEC

Effect conc.:

0.906 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

1.09 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95 % CL: n.d.

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.326 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

0.906 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Signs of Intoxication after 24 Hours: After 24 hours in the control and in the concentrations up to and including 0.326 mg test item/L, no immobilisation of the test animals was observed. At the two highest test concentration of 0.906 and 2.742 mg test item/L, 4 and 10 daphnids were immobile after 24 hours test duration, respectively.
Signs of Intoxication after 48 Hours: At the end of the test the toxicity of the test item to Daphnia magna had increased. After 48 hours of exposure no immobilisation of the test animals was observed in the control and up to and including the test item concentration of 0. 0298 mg test item/L. At the concentration of 0.906 mg test item/L, four animals were immobile and 20 animals were immobile at the concentration of 2.742 mg test item/L.
Moreover, two daphnids were dead in each replicate number 4 of the concentration steps 0.0443 and 0.0754 mg test item/L. These daphnid are not considered within the statistical evaluation as it seems not to be a substance related effect rather than a mechanistic effect.

Results with reference substance (positive control):

In the most recent test with the reference item potassium dichromate performed in July 2013 (study code 71478220) the EC50 after 24 hours was determined to be 1.479 mg test item/L indicating that the sensitivity of the Daphnia was consistent with the level proposed by the OECD 202 guideline (EC50-24 h between 0.6 and 2.1 mg potassium dichromate/L).

Reported statistics and error estimates:

The 24-hour and 48-hour EC50, EC20 and EC10 and the 95 % confidence limits were calculated by Probit analysis.
The NOEC and LOEC after 24 and 48 hours were determined directly from the raw data.
The software used to perform the statistical analysis was ToxRat Professional, Version 2.10.05, ToxRat Solutions GmbH.

Analytical Results:

Nominal Test Concentrations: 3.35, 1.52, 0.69, 0.315, 0.143 and 0.065 mg test item/L and a control (water only) corresponding to geometric mean measured values of 2.742, 0.906, 0.326, 0.0754, 0.0443, 0.0298 mg test item/L.

At the start of the test and in the freshly prepared test media at the renewal on day 1, 102% of the nominal test concentration was found

(average of all test concentrations).

After 24 hours test duration (at day 1 and day 2) a significantly reduced test item concentration was determined in all test treatment

samples.

Immobility results

Nominal concentration (mg/L)	Mean measured conc. (mg/L)	No. of immobilised Daphnia		% immobility
		24 h	48 h	24 h	48 h
Control	Control	0	0	0	0
0.065	0.0298	0	0	0	0
0.143	0.0443	0	2	0	10
0.315	0.0754	0	2	0	10
0.69	0.326	0	0	0	0
1.52	0.906	4	4	20	20
3.35	2.742	10	20	50	100

Validity criteria fulfilled:

yes

Conclusions:

The effect of the test item Catechol to Daphnia magna was assessed in a semi-static 48-hour test with closed vessels in the dark by visual observation after 24 and 48 hours. The 48-hour NOEC was determined to be 0.326 mg test item/L. The 48- hour LOEC was determined to be 0.906 mg test item/L and the 48- hour EC50 value was calculated to be 1.09 mg test item/L.

Executive summary:

The purpose of this study was to evaluate the acute toxicity of Catechol to Daphnia magna was assessed in a semi-static 48-hour test with closed vessels in the dark by visual observation after 24 and 48 hours. This study was carried out to OECD Guideline 202. Nominal exposure concentrations were 0 (control), 3.35, 1.52, 0.69, 0.315, 0.143 and 0.065 mg test item/L corresponding to geometric mean measured values of 2.742, 0.906, 0.326, 0.0754, 0.0443, 0.0298 mg test item/L. The results of the study are based on the geometric mean measured exposure concentrations.

The 48-hour NOEC was determined to be 0.326 mg test item/L. The 48- hour LOEC was determined to be 0.906 mg test item/L and the 48- hour EC50 value was calculated to be 1.09 mg test item/L.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Remarks:

The test was performed according to the French standardised AFNOR method NF T90301. The experimental conditions and the obtained results were described with a lower level of details than the precedent study. Nevertheless, the results of both experiments were highly consistent. As previously, this 24-hour study was carried out before the appearance of the 48-hour recommendation, when a 24-hour exposure period was still judged as relevant.

Qualifier:

equivalent or similar to guideline

Guideline:

other: French Standard AFNOR T 90301

Deviations:

not specified

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

not specified

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A stock solution of 1000 mg/L was prepared in distilled water.
No further data.

Test organisms (species):

Daphnia magna

Details on test organisms:

No data

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

24 h

Hardness:

No data

Test temperature:

No data

pH:

No data

Dissolved oxygen:

No data

Salinity:

Not applicable

Nominal and measured concentrations:

One control (without catechol) and 6 concentrations (1.4, 1.8, 2.1, 2.6, 3.3 and 5 mg/L) were tested.

Details on test conditions:

No data, except that the experimental conditions followed those described in the AFNOR standardised method.

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

2.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Validity criteria fulfilled:

not specified

Conclusions:

Catechol was toxic for Daphnia magna under the tested conditions.

Executive summary:

In a study (Rhône-Poulenc, 1977), the 24-hour acute toxicity of Catechol to Daphnia magna was studied under static conditions. Daphnids were exposed to test chemical at nominal concentrations of 0, 1.4, 1.8, 2.1, 2.6, 3.3 and 5 mg/L for 24 hours. Mortality was observed . 

The 24 hours EC₅₀ was 2.1 mg/L.

Based on the results of this study, Catechol is considered to be toxic to Daphnia magna.

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Remarks:

The test was performed according to the French standardised AFNOR method NF T90301. The experimental conditions and the obtained results were described with a relatively high level of details. This 24-hour study was carried out before the appearance of the 48-hour recommendation, when a 24-hour exposure period was still judged as relevant.

Qualifier:

equivalent or similar to guideline

Guideline:

other: French Standard AFNOR T 90301

Deviations:

yes

Remarks:

Dissolved oxygen, age of daphnids, exposure duration

GLP compliance:

not specified

Analytical monitoring:

not specified

Vehicle:

not specified

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Pyrocatechol was diluted with AFNOR reconstituted hard water for toxicity test.
- Controls: Yes, test water without test item.
No further data

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain: Daphnia magna Straus
- Source: IRCHA Laboratory
- Age at study initiation (mean and range, SD): < 72h old.
- Method of breeding: cultured parthenogenetically in Pasteur Institute Laboratory since 1975. the brood stock was kept in an environmental chamber at 22 +/- 1 °C, with a photoperiod of 16 hours daylight / 8 hours darkness. Daphnids were fed with a diet of Chlorella vulgaris (1 x 10E6 algal cells per daphnids per day.
- Feeding during test: no

ACCLIMATION: no data

QUARANTINE: no data

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

24 h

Hardness:

200 mg/L CaCO3

Test temperature:

20 +/- 1°C

pH:

7.8 - 8.2

Dissolved oxygen:

No data

Salinity:

Not applicable

Nominal and measured concentrations:

No data

Details on test conditions:

TEST SYSTEM
- Test vessel: No data
- Aeration: No aeration during the test
- Type of flow-through (e.g. peristaltic or proportional diluter): Not applicable (static test)
- Renewal rate of test solution (frequency/flow rate): Not applicable (static test)
- No. of organisms per vessel: No data
- No. of vessels per concentration (replicates): Catechol was assayed in duplicate for a minimum of three replicate on following days.
- No. of vessels per control (replicates): No data
No further data.

TEST MEDIUM / WATER PARAMETERS
No data

OTHER TEST CONDITIONS
- Photoperiod: The test was performed under darkness.
No further data

EFFECT PARAMETERS MEASURED (with observation intervals if applicable)
Percentages of immobilized daphnids were assessed.

TEST CONCENTRATIONS
No data

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

24 h

Dose descriptor:

IC50

Effect conc.:

1.67 mg/L

Nominal / measured:

not specified

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks:

(immobilization)

Remarks on result:

other: 95% CL: 1.25 - 2.08

Details on results:

In the publication, the 24h-IC50 (= C) and 95% confidence intervals were expressed as logarithm of the inverse millimolar concentration (mmol/L-1). The following calculation was thus done to obtain the 24h-IC50 in mg/L :

log (1/C) = log 1 - log C = 1.820
log C = log 1 - 1.820 = 0 - 1.820 = 1.820
C = exp (ln (10) x (-1.820)) = exp (-4.1907138) = 0.01513548 mmol/L = 1.513548 x 10E-5 mol/L

C (g/L) = molecular weight (g/mol) x C (mol/L)
C (g/L) = 110.1122 x 1.513548 x 10E-5 = 0.001666
C = 1.67 mg/L

Results with reference substance (positive control):

No data

Reported statistics and error estimates:

The IC50 value (immobilization concentration for 50 % of daphnids at 24 hours) was extrapolated from empirical curve fitted by eye on log-probit paper with % of immobilization and log of the concentrations on the axes.

Validity criteria fulfilled:

not specified

Conclusions:

Catechol was toxic for Daphnia magna under the tested conditions.

Executive summary:

Devillers (1987) investigated the 24-hour acute toxicity of Catechol to Daphnia magna under static conditions. No data was available on the concentrations tested. Mortality/immobilization was observed during test.

The 24 hours IC₅₀was 1.67 mg/L.

Based on the results of this study, Catechol is considered to be toxic to Daphnia magna.

Description of key information

The 48-hour EC50 of catechol for Daphnia magna is 1.09 mg/l (study report).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

1.09 mg/L

Additional information

Among the available studies only one study had a reliability 1 according to Klimisch (Seeland-Fremer et al., 2014). Two other studies had a lower reliability of 2 and were considered supporting studies. The 24-hour EC50 were 1.67 mg/L and 2.1 mg/L, respectively. In view of the chemical safety assessment, the lowest value of 1.09 mg/l was retained.

During the study of Seeland-Fremer et al. (2014) a significant decrease in the test concentration was found after 24 hours of exposure. The decrease in concentration could be caused by oxidation of catechol.

Another study (Bringman & Kühn, 1959) of reliability 3 was gave a consistent result (48h-EC50 = 4 mg/L), despite an unusual measurement of daphnids mobility. The other available studies were not enough described or performed on non standardised species, and does not allow to judge of the short-term toxicity of catechol on aquatic invertebrates.

Based on the results of the reliable studies, catechol is considered to be toxic to Daphnia magna.