Terephthaloyl dichloride

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

Remarks:

This study is used for read-across and therefore has been assigned a reliability of 2 (reliable with restrictions). The study, if used in support of terephthalic acid, has a reliability of 1 (reliable without restriction). OECD Guideline, GLP study.

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Sampling conducted at 0 and 96 hours.

Vehicle:

no

Details on test solutions:

For the range finding test, the test material was directly weighed into the test vessel. No stock solution was made. The test material was dissolved in reconstituted water. Not all the test material dissolved.

Based on the experience in the range finding test, a stock solution was prepared for the definitive test and the test material only dissolved after addition of NaOH for pH adjustment. The concentration of the stock solution was 1000 mg/L.

Test organisms (species):

Leuciscus idus melanotus

Details on test organisms:

The test organisms were Leuciscus idus melanotus.

For the range finding test the supplier was West Aquarium, Scharzfelder 101, D-3422 Bad Lauterburg. Purchased on 26 March 1991.
Before the test the fish were fed 50% Tetra Special Mix; 50% IBL Novo food tablets. The amount depended on their bodyweight; 2% of mean fish weight. The feeding frequency was 5 times per week. The average body weight of the fish was 1.383 ±0.305 (S.D.) g/fish

Other environmental conditions in the vessel before the test were;
Photoperiod: dark/light 8/16 h
Light intensity; approximately 50 Lux
Duration of acclimatisation; 20 d [recommended:>12 d]

For the definitive test the supplier was Eurofisch, D-2354 Hohenweststadt. Purchased on the 30 July, 1991. The fish were fed 50% Tetra Special Mix; 50% IBL Novo food tablets. The amount depended on their bodyweight; 2% of mean fish weight. The feeding frequency was 5 times per week. The average body weight of the fish was 1.028 ±0.29 (S.D.) g/fish.

Other environmental conditions in the vessel before the test were;
Photoperiod: dark/light 8/16 h
Light intensity; approximately 100 Lux
Duration of acclimatisation; 21 d [recommended:>12 d]

The conditions during the test are noted in test conditions below.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

193.86 mg/L in CaCO3

Test temperature:

22 ±1 °C

pH:

7.8

Dissolved oxygen:

92%

Salinity:

freshwater

Nominal and measured concentrations:

nominal concentrations used. The actual concentration is measured at 0 h and 48 h.

Details on test conditions:

A range finding study is conducted to determine the concentrations to be tested in the definitive study. During the range finding test the conditions were
- Test vessel:
- glass vessel of size 16 L; height: 20 cm; length: 31.5 cm; width:29 cm
-depth of water: approx 12.5 cm.
- no renewal of test solution
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 0
- No. of vessels per vehicle control (replicates): 0
-Loading 1.383 g/L
-Photoperiod: dark/light 8/16 h
-light intensity; approximately 200 Lux
-Temperature 22 ±1 ⁰C
-feeding: none


During the definitive test the following conditions were used;
- Test vessel:
- glass vessel of size 16 L; height: 20 cm; length: 31.5 cm; width:29 cm
-depth of water: approx 12.5 cm
-Test vessels were aerated to maintain acceptable dissolved oxygen levels.
-Amount of test solution per test vessel; 10 L.
- no renewal of test solution
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
-Loading 1.028 g/L
-Photoperiod: dark/light 8/16 h
-light intensity; approximately 200 Lux
-Temperature 22 ±1 ⁰C
-feeding: none

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 961 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

961 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

other: mortality and behavioural abnormalities

Details on results:

Results from the range finding study showed that the highest concentration causing no mortality within the period of the range finding test was 1000 mg/L. The lowest concentration causing 100% mortality within the period of the range finding test was >1000 mg/L.

From the results obtained in the range finding study, the concentrations for the definitive test were chosen. The nominal concentrations to which the test organisms were exposed were 130, 220, 350, 600 and 1000 mg/L Terephthalic Acid. The analytically determined actual concentrations at the beginning of the study was on average 103.8%. While at the end of the study after 96 hours of exposure was found to be on average 73.3%.

Before the start of the test the pH of the stock solution was adjusted to the required physiological value. It is believed that after pH adjustment Terephthalic Sodium salt was the test material investigated in this test rather than Terephthalic Acid.

Based on the measured average concentration (92.2%) of the highest concentration level tested (nominally 1000 mg/L) the result of the study was LC0 (96h) is >922 mg/L. A LC50 value could not be determined as it exceeded the highest concentration applied.

In the report, the endpoint is given as >922 mg/L, apparently the mean measured value at the highest concentration, but based on the 96-h data only, i.e. (938.4 + 906.0)/2. The mean should include the 0-h data as well, i.e. (916.6 + 1082 + 938.4 + 906)/4 = 961 mg/L.

Reported statistics and error estimates:

not reported

Sublethal observations / clinical signs:

Table 1 Results of Range-finding test (no. mortalities/number of fish per treatment) for L. idus melanotus exposed to terephthalic acid (sodium terephthalate)

Conc	Control	1	10	100	1000
Time
0	0/10	0/10	0/10	0/10	0/10
24	0/10	0/10	0/10	0/10	0/10
48	0/10	0/10	0/10	0/10	0/10
96	0/10	0/10	0/10	0/10	0/10

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Table 2   Definitive test results: Effects of terephthalic acid (sodium terephthalate) on L. idus melanotus in a 96 -hour, acute toxicity test under static conditions. Percentage mortality and (cumulative no. mortalities/number of fish per treatment).

Conc	"Salinity Control"*	Control	80	130	220	350	600	1000
Time
0	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)
3	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)
6	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)
24	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)
48	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)
72	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)
96	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)	0% (0/10)

*The "salinity control" consisted of dilution water amended with NaOH solution only.

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Table 3 Measured concentrations of terephthalic acid during a 96 hour, static acute toxicity test with L. idus melanotus

Exposure Period (h)	Terephthalic Acid Nominal mg/L	Measured Terephthalic Acid mg/L	Percentage of nominal %
0	130	126.2 139.5	98 108
0	350	365.8 399.8	106 115
0	1000	916.6 1082	93 109
96	130	90.4 92.4	70 72
96	350	212.8 185.9	61 54
96	1000	938.4 906.0	95 92

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In the report, the endpoint is given as >922 mg/L, apparently the mean measured value at the highest concentration, but based on the 96-h data only, i.e. (938.4 + 906.0)/2. This is incorrect; the mean should include the 0-h data as well, i.e. (916.6 + 1082 + 938.4 + 906)/4 = 961 mg/L.

 

Validity criteria fulfilled:

yes

Conclusions:

This study and the conclusions which are drawn from it fulfil the quality criteria (validity, reliability, repeatability).

The static 96-h LC50 of the test substance (converted to its sodium salt prior to exposure) to L. idus melanotus was >961 mg/L, based on the mean measured concentration at the maximum treatment applied.

Executive summary:

Golden orfe (L. idus melanotus) were exposed in a static test system over a period of 96 hours to the test substance (TS) after conversion to its sodium salt. The nominal concentrations to which the test organisms were exposed were 80, 130, 220, 350, 600 and 1000 mg TS/L. There were single test vessels per treatment, each containing 10 fish. Exposure concentrations were verified analytically at the start and end of the test in three of the treatments. The analytically determined initial concentrations of the test substance were between 93% and 115% of nominals. Residual concentrations at test-end were between 54% and 95% of nominals in all three treatments that were analysed, and 95% to 92% of nominal at the maximum concentration which defined the endpoint of the study.

The LC₅₀(96 h) was >961 mg/L test substance (tested as sodium terephthalate), based on the mean measured exposure concentration at the highest treatment. Based on the absence of treatment-related mortalities or sub-lethal effects, the NOEC was 961 mg TS/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

961 mg/L

Additional information

The study was conducted using terephthalic acid, the primary degradate of terephthaloyl dichloride, according to OECD 203 under GLP. Golden orfe (L. idus melanotus) were exposed in a static test system over a period of 96 hours to the test substance after conversion to its sodium salt. The nominal concentrations to which the test organisms were exposed were 80, 130, 220, 350, 600 and 1000 mg/L. Exposure concentrations were verified analytically at the start and end of the test and were between 93% and 115% of the nominal values.

The static 96-h LC₅₀ of the test substance (converted to its sodium salt prior to exposure) to L. idus melanotus was >961 mg/L, based on the mean measured concentration at the maximum treatment applied. Based on the absence of treatment-related mortalities or sub-lethal effects, the NOEC was 961 mg/L.