''amyl nitrite'', mixed isomers

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

''amyl nitrite'', mixed isomers

EC Number:

203-770-8

EC Name:

''amyl nitrite'', mixed isomers

Cas Number:

110-46-3

Molecular formula:

C5H11NO2

IUPAC Name:

pentyl nitrite

Test organisms

Test organisms (species):

Daphnia magna

Test conditions

Hardness:

Between 140 and 250 mg.L-1

Test temperature:

20 °C ± 2

pH:

Between 6 and 9

Details on test conditions:

Light/dark cycle: 16 h/8 h

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.307 mg/L

Basis for effect:

mobility

Effect concentrations 2

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

0.307 mg/L

Basis for effect:

mobility

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The objective of this study was to assess the effects of the test item Isoamyl Nitrite on the mobility of Daphnia magna over a period of 48 hours under static conditions according to OECD Guideline 202 (April 2004).

Since the substance is volatile and is not soluble in under conditions of the test, the test was carried out in closed bottles and the substance was added by injection through the septum.

Test item quantification was performed according to a validated analytical method (final report RRCo-000234_01) on a GC-MS/MS from Agilent (GC 7890b and MS triple quadrupole 7000b or c) as mass spectrometry detection was found suitable to measure Isoamyl Nitrite concentrations at 0 and 48 hours.

Results are the following:

Isoamyl Nitrite
EC50 (24h) 0.317 mg.L-1 (0.307 – 0.327 mg.L-1)
EC50 (48h) 0.317 mg.L-1 (0.307 – 0.327 mg.L-1)
EC = effect concentration

The acute effects of Isoamyl Nitrite at the definitive nominal concentrations of 0; 0.31; 0.63; 1.25; 2.5 and 5 mg.L-1 to Daphnia magna were investigated under laboratory conditions.
Due to the instability of test item, the calculations were performed on the measured concentrations at initial time.

The study is valid since immobilization in the control was less than 10% (actual values: 0% in the definitive test), dissolved oxygen in the lowest concentration producing the maximum effect at the end of the test was ≥ 3 mg.L-1 (actual values: 8.5 mg.L-1 in the definitive test) and the EC50 with reference item over a period of 24 hours was between 0.6 and 2.1 mg.L-1 (actual value: 1.44 mg.L-1).

Based on the number of immobilized daphnids, the EC50 after a 24-hour exposure period was calculated to be 0.317 mg.L-1 (0.307 – 0.327 mg.L-1 95% confidence limits), and the EC50 after a 48-hour exposure period was calculated to be 0.317 mg.L-1 (0.307 – 0.327 mg.L-1 95% confidence limits).