Naphthalene-2,6-dicarboxylic acid

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:

16 March 2018 - 19 July 2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

The photoperiod devided from the study plan. The temperature range devided from the guideline. For details see section "Results and Discussion"

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

The temperature range exeeded the one recommended in the guideline. However, both deviations did not have an influence on the outcome of the study. For details see section "Results and Discussion".

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Batch No.of test material: 0012747069
- Expiration date of the batch: 24 January 2019

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: At ambient temperature
- Stability under test conditions: stable

Analytical monitoring:

yes

Details on sampling:

- Concentrations: All test concentrations
- Sample storage conditions before analysis: Samples were stored in amber glass bottles in a freezer and shipped on dry ice to the analytical lab

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION

A stock solution at a nominal loading rate of 100 mg/L was prepared. This stock solution was stirred for 10 min at ca. 1000 rpm, then ultrasonicated for 3 min and subsequently stirred for 68 hours at ambient temperature in the dark with 500 rpm. After 30 minutes without stirring, particles were observed. Thereafter, the stock solution was filtered, using a glass fibre filter. The first 0.5 L of the filtrate were discarded, visual inspection of the filtrate showed no undissolved test item particles was visible in the filtrate. The filtrate (stock solution, S2) was used to prepare the desired test item concentrations and was used immediately after preparation.

Method: OECD 2000, Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures. OECD Series on Testing and Assessment Number 23. ENV/JM/MONO(2000)6.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebrafish
- Spawning date: November 2017
- Strain: Stock culture
- Source: Lab breeding
- Length at study initiation: 2.2 - 2.5 cm, mean 2.35 cm
- Weight at study initiation: 0.0714 - 0.1053 g/fish, mean 0.0947 g/fish

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

9.0 - 9.8°dH

Test temperature:

19.2 - 24.3°C

pH:

6.1 - 7.6

Dissolved oxygen:

7.6 - 8.5 mg/L (92 - 96%)

Conductivity:

779 - 803 µS/cm²

Nominal and measured concentrations:

Nominal: 0 and 100 mg/L
Measured: 0 and 36.2 mg/L (filtrate of a saturated solution at the loading rate of 100 mg/L)

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass vessels, 22 L
- Type: open
- Size, fill volume: 7 L fill volume, depth of the test solution 14 cm
- No. of organisms per vessel: 7
- Aeration: permanent
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 0.0947 g/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: A saturated stock solution of 100 mg/L was prepared.
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 14h light/10 hours dark
- Light intensity: 385 lx (measured)

EFFECT PARAMETERS MEASURED (with observation intervals if applicable):
Fish were observed daily for mortality and abnormal behaviour

TEST CONCENTRATIONS
- Spacing factor for test concentrations: none (limit test)
- Range finding study : yes
- 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.:

> 36.2 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: loading rate 100 mg/L

Details on results:

- Behavioural abnormalities:
- Other biological observations: no adverse effects wer observed
- Mortality of control: no
- Other adverse effects control:no

Sublethal observations / clinical signs:

The temperature range differed from the one stated in the guideline. Due to a malfunction of the climatisation device the temperature fell below the limit of 21°C (measured temperature: 19.4°C). After installation of another temperature device the temperature increased up to 24.7°C. Consequently the temperature range also exceeded the maximum variation of ±1.0°C throughout the test period by ±2.65°C. Since the fish did not show any abnormal behaviour and/or mortalities at the control and the limit concentration level, this temperature variation is expected to have no influence on the biological outcome of this study and also no influence on the integrity of the study. This is supported by the results of the non-GLP range finder where the temperature range was kept between the one recommended by the guideline. No mortalities or abnormal effects could be seen in any of the concentrations tested. Furthermore, the measured values of the saturated stock solution was lower in the range finder than in the definite test (27.9 mg/L). As the results of the range-finder indicated that the definite test can be conducted as a range finder, and as the test concentration of the saturated solution was higer in the definite test as in the range-finding test, it can be concluded that the deviation of the temperature range has no influence on the integrity of the study.

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the test, it can be concluded that 2,6-naphthalene dicarboxylic acid has a low toxicity to zebrafish with a LC50 of above 36.2 mg/L based on measured values of a 100% saturated solution of 100 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

36.2 mg/L

Additional information

The LC50 is based on measured values of a 100% stock solution of 100 mg/L.