1,2-dihydro-3H-1,2,4-triazol-3-one

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:

This study was conducted between the 14th and 22nd of December 2017.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

10 December 20009

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Identification Product Information:
Product Name Triazolone
Batch number 0727/16
CAS number 930-33-6
NIVA substance number G130
Substance appearance Crystalline white powder
Date received 18.05.2017
Storage conditions Closed in bottle, dry at ambient temperature
Expiry data June 2021
Stability Triazolone can be stored for at least five years when stored according to recommended storage conditions; dry, room temperature in unopened original packaging.

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

The test medium used for the test was supplied by the Norwegian University of Life Sciences and was the same media as was used to culture the parent zebrafish. This media was composed of Instant Ocean (0.155 g/L), sodium bicarbonate (0.053 g/L) and calcium chloride (0.015 g/L) added to reverse osmosis water. The pH and conductivity of the test media was specified to be 7.5 and 400 µS/cm, respectively.

A single limit test of 100 mg/L Triazolone was used

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

Name Danio rerio (zebrafish)
Strain AB wild type
Source Norwegian University of Life Sciences.
Stock culture Zebrafish cultured in Model fish unit system water (Non GLP).
Justification Zebrafish were used as the test organism as they are easily produced within the laboratory. They are also an accepted species according to OECD 203.

Test type:

static

Water media type:

saltwater

Limit test:

yes

Total exposure duration:

96 h

Remarks on exposure duration:

The fish were observed after 3 hours and then at 24-hour intervals to determine if any adverse effects were seen during the study. At the end of the test, all fish were terminated using an overdose of anaesthetic

Test temperature:

23±2 ”C

pH:

7.5

Conductivity:

400 µS/cm

Nominal and measured concentrations:

Nominal 100 mg/l

Details on test conditions:

Test medium
The test medium used for the test was supplied by the Norwegian University of Life Sciences and was the same media as was used to culture the parent zebrafish. This media was composed of Instant Ocean (0.155 g/L), sodium bicarbonate (0.053 g/L) and calcium chloride (0.015 g/L) added to reverse osmosis water. The pH and conductivity of the test media was specified to be 7.5 and 400 µS/cm, respectively.

Experimental design
A single limit test of 100 mg/L Triazolone was used and only 1 replicate per test concentration and control with 7 fish per test concentration and control. This is the minimum number of fish recommended in OECD 203. The test was performed in 2 L glass beakers with a loose-fitting lid to avoid evaporation. The limit test concentration (100 mg/L) was prepared by adding 0.1998 g of test substance to 2 L of dilution water. The test duration was 96 hours and there was no renewal of test medium during the test. The test was performed at 23 ± 2ºC. The test vessels were aerated throughout the study.

Exposure conditions
The beakers were maintained in an incubator set to 24ºC in a climate controlled room. The room was set with a photoperiod of 8 hours dark to 16 hours light cycle.
Test procedure and Observations
The pH and dissolved oxygen were measured with an ORION STAR A211 pH meter and an Inolab OXI7310 oxygen meter, in the limit test concentration and control at the start and end of the test. The temperature during the test was recorded on a min./max. thermometer with the sensor placed in water at the level of the test cultures.

The fish were observed after 3 hours and then at 24-hour intervals to determine if any adverse effects were seen during the study. At the end of the test, all fish were terminated using an overdose of anaesthetic.

Data evaluation
As this was a limit study, no effects were expected to be observed after 96 hours exposure so no data evaluation was necessary.

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

not determinable

Details on results:

Validity criteria
The test met all the validity criteria (Table 1), so it is considered valid

Physicochemical parameters
The following pH ranges were recorded during the test:
Min: 7.65, Max: 8.13.

The following Dissolved Oxygen ranges were recorded during the test:
Min: 8.83 mg/L, Max: 9.02 mg/L

The following temperatures were recorded during the test:
Min: 23.8 ºC, Max: 24.3 ºC.


Fish observations
The fish were observed after 3 hours and then at 24 hour intervals until the end of the study at 96 hours. No observations of any effects were observed during the study and hence the LC50 can only be represented as >100 mg/L. At the end of the test, the fish were terminated using an overdose of anaesthetic (MS222) and 7 fish were weighed (total weight 0.86g).

Sublethal observations / clinical signs:

Table 1. Summary of results from the validity criteria

Parameter	Criterion	Observed
Control fish survivability	<10%	0%
Dissolved oxygen	> 3 mg/L	8.83-9.02 mg/L

Validity criteria fulfilled:

yes

Conclusions:

The test substance Triazolone caused no effects on zebrafish over the 96 hour test period at a concentration of 100 mg/L. Therefore the 96 hour LC50 for Triazolone is >100 mg/L

Executive summary:

The acute toxicity of Triazolone to fish has been investigated. The test is part of the base set requirements (i.e., algae, invertebrates and fish) for determining the potential effects of the chemical in the environment. The test is designed to determine the lethal concentration which kills 50% of the population (LC50). The test was performed according to OECD test guideline 203 (OECD, 2009) and used zebrafish (Danio rerio) as the test organism. A single limit test of 100 mg/L Triazolone was performed along with a dilution water control. The test was performed at a test temperature of 23 °C ± 2 and fish were observed after 3, 24, 48, 72 and 96 hours. No evidence of adverse effects were observed during the study and no mortalities occurred. Therefore the 96 hour LC50 for Triazolone exposed to zebrafish is >100 mg/L.

Description of key information

The acute toxicity of Triazolone to fish has been investigated. The test is part of the base set requirements (i.e., algae, invertebrates and fish) for determining the potential effects of the chemical in the environment. The test is designed to determine the lethal concentration which kills 50% of the population (LC50). The test was performed according to OECD test guideline 203 (OECD, 2009) and used zebrafish (Danio rerio) as the test organism. A single limit test of 100 mg/L Triazolone was performed along with a dilution water control. The test was performed at a test temperature of 23 °C ± 2 and fish were observed after 3, 24, 48, 72 and 96 hours. No evidence of adverse effects were observed during the study and no mortalities occurred. Therefore the 96 hour LC50 for Triazolone exposed to zebrafish is >100 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

100 mg/L