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

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

January-february 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Identification Triazolone
NIVA substance number G130
CAS No. 930-33-6
Batch No. 0727/16
REACH registration No. Not stated
EC No. Not stated
Purity >99%
Water solubility 60 g/l
Substance appearance Crystalline, white
Date received 18.05.2017
Storage conditions Closed in container, dry at ambient temperature
Expiry data June 2021
Stability Stable under normal temperature conditions and recommended use.

Analytical monitoring:

no

Details on sampling:

none

Vehicle:

no

Details on test solutions:

A stock solution of 10 mg/L, the highest test concentration in the study, were prepared by adding 500 ml M7 to 5.03 mg triazolone. This solution was also used to prepare the remaining test concentrations.

Test organisms (species):

Daphnia magna

Details on test organisms:

Name Daphnia magna
Source In house cultures at NIVA (DHI – clone)
Culture details The Daphnia are cultured in Elendt M7 media under the same conditions as used in the test according to a standard operating procedure. Cultures are fed with Psedukirchineriella subcapitata.
Life-stage/Age Animals used for the test were young daphnia, less than 24 hours old
Justification Daphnia magna were used as the test organism as they are easily cultured within the laboratory and are recommended for use in freshwater ecotoxicity assessments

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

not specified

Test temperature:

19.3 - 21.3°C

pH:

8.84 - 10.26

Dissolved oxygen:

8.84-10.26 mg/L

Salinity:

NA

Conductivity:

not specified

Nominal and measured concentrations:

nominal concentrations: 0, 0.1, 0.32, 1, 3.2, 10 mg/L

Details on test conditions:

The exposure vessels were placed in a climate controlled room set to 20ºC with a photoperiod providing 16 hours light: 8 hours dark. The temperature should be in the range 18 – 22 ºC, and for the test should not vary more than ± 1ºC Daphnids were not fed during the exposure period.

All test vessels were rinsed with appropriate test solution prior to being filled for the test. After preparation of the test solutions and rinsing of test vessels, the test solutions were dispensed into the test vessels to give approximately 40 ml of solution per replicate. Test solutions were dispensed moving up the concentration gradient and starting with the control. The test vessels were identified by study number, concentration, and replicate
number.

The study was initiated with the addition of the daphnids. At 24 hour intervals, observations were made for immobilisation and these data were recorded in the study book. Immobilisation is defined as the inability of the organism to swim within 15 seconds after gentle agitation of the test vessel, even if movement of antennae is observed. The daphnids were not fed during the study. At the start and end of the test, samples were removed for physicochemical analysis.

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

ca. 9.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Key result

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

ca. 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

ca. 3.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

No immobility was observed in the controls at 24h or 48h exposure. No immobile daphnia were observed after 24h of exposure (Table 3). After 48h of exposure, 12 of 21 D. magna exposed to 10 mg/L were immobile. See appendix 2 for overview of data. The results of the study are summarised in Table 4.

Results with reference substance (positive control):

NA

Reported statistics and error estimates:

none

none

Validity criteria fulfilled:

yes

Conclusions:

The EC50 of the test substance after 48h exposure was 9.6 mg/L. The NOEC and LOEC for immobility after 24h of exposure to triazolone were ≥ 10 mg/L (NOEC) and > 10 mg/L (LOEC). The NOEC and LOEC for immobility after 48h of exposure to triazolone were 3.2 mg/L (NOEC) and 10 mg/L (LOEC).

Executive summary:

The acute toxicity of Triazolone to the freshwater crustacean Daphnia magna was investigated. The test was performed according to OECD 202 (2004) Daphnia sp. Acute immobilisation test [1]. The test animals were young daphnia, less than 24h old, from in house cultures (DHI clone) at NIVA.

A range of concentrations (0.1, 0.32, 1, 3.2, and 10 mg/L) were prepared in Elendt M7 medium. The M7 medium control was shared with study 17159/5 and 17159/6. Four replicate vessels, each containing five D. magna were employed for the control and each treatment. Immobility was assessed at 24h and 48h.

The objective of the study was to determine the median effective concentration (EC50) of the test substance for 24h and 48h exposure. The EC50 could only be determined after 48h exposure and was 9.6 mg/L.

Description of key information

The acute toxicity of Triazolone to the freshwater crustacean Daphnia magna was investigated. The test was performed according to OECD 202 (2004) Daphnia sp. Acute immobilisation test [1]. The test animals were young daphnia, less than 24h old, from in house cultures (DHI clone) at NIVA.

A range of concentrations (0.1, 0.32, 1, 3.2, and 10 mg/L) were prepared in Elendt M7 medium. The M7 medium control was shared with study 17159/5 and 17159/6. Four replicate vessels, each containing five D. magna were employed for the control and each treatment. Immobility was assessed at 24h and 48h.

The objective of the study was to determine the median effective concentration (EC50) of the test substance for 24h and 48h exposure. The EC50 could only be determined after 48h exposure and was 9.6 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

9.6 mg/L