2-Butanone, peroxide

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:

2001-01-19 to 2001-04-25

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

part I (4/4/84)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

A stock solution of the test item diluted in water was prepared at the beginning of the test (time 0) by mixing 100 mg of methyl ethyl ketone peroxide in phthalate plasticizer per litre of dilution water. After few minutes of agitation the stock solution appeared to be clear, homogeneous and colourless.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Strain: Daphnia magna Straus (Cladocera, Crustacea)
- Source: a stock breading in the test laboratory reared in Volic water added with Vitamin B12, Na2SeO3, 5 H2O, spiruline, unicellar green fresh-water algae Pseudokirchneriella subcapitata
- Age at study initiation (mean and range, SD): less than 24 hours old

ACCLIMATION
- Acclimation period: 24 hours
- Acclimation conditions (same as test or not): test flasks were incubated in darkness at a temperatue of 19 ± 1 °C.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test temperature:

19 ± 1 °C

pH:

7.70 to 7.81

Dissolved oxygen:

- 7.8 to 8.8 mg/L (after 48 h)
- 10.0 to 10.8 mg/L (0 h)

Nominal and measured concentrations:

- nominal concentrations: 0, 7.9, 11.9, 17.8, 26.7, 40.0 and 60 mg/L
- Initial concentrations (measured in solutions): 8.28, 12.42, 18.38, 27.94, 41.57, 64.88 mg/L

Details on test conditions:

The study was performed using 120 mL glass bottles stoppered with PTFE bungs and sealed with aluminium caps. The study was performed in a thermostated room. The temperature remained between 18 and 20 °C.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

39 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

39 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

26.7 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

The final concentrations of methyl-ethylketone peroxide in Phthalate plasticizer were maintained within the designated limit of 80 % of the initial concentrations in test solutions. Thus, the test item concentrations were maintained throughout the duration of the test.
Since the initial mesured concentrations in flaks (without Daphnia) were found to be equivalent (> 80 %) to the nominal concentrations, calculations of effective concentration EC50 were performed using nominal values.
The following effective concentrations show results obtained by regression analysis using the Probit/log model: EC50 (24h) = 39 mg/L and EC50 (48h) = 39 mg/L.

The percentage inhibition of daphnia mobility are presented in the following table:

Nominal concentration (mg/L)	Immobilisation (%)
	24 h	48 h
0	0	0
7.9	0	0
11.9	0	0
17.8	0	0
26.7	0	0
40.0	70	70
60.0	100	100

 

The following table presents the concentrations (mg/L) of Methyl ethyl ketone peroxide in phthalate Plasticizer measured in the test solutions at the beginning (without daphnia) and the end (with daphnia) of the test:

Equivalent concentration of Methyl ethyl ketone peroxide in Phthalate plasticizer
Nominal (%vol.)	Measured in solutions
	Initial (mg/L)	Final (mg/L)	Final/ Initial (%)
7.9	8.28	ND	-
11.9	12.42	ND	-
17.8	18.38	ND	-
26.7	17.94	26.59	95
40.0	41.57	39.20	94
60.0	64.88	63.54	98

ND: Concentrations not determined.

Validity criteria fulfilled:

yes

Conclusions:

The EC50-values of methyl-ethylketone peroxide were 39 mg/L after 24 and 48 hours.

Executive summary:

The acute toxicity (inhibition of mobility) of methyl-ethylketone peroxide in DMP to Daphnia magna was assessed according to the method C.2 of the European Directive 92/69/CEE and in the guideline 202 (part I) of the OECD. The test was performed using closed flasks as testing vessels. The flasks were entirely filled with test solutions and closed with butyl rubber caps covered with PTFE. Daphnia were exposed in a static test to a concentration range of 7.9 to 60 mg/L, forming a geometric progression with a factor of 1.5. The test was performed with 20 Daphnia per vessel. Testing flasks were incubated in darkness at 19 ± 1 °C for 48 hours. For each exposure concentration, the percentage of immobilisation after 24 hours and 48 hours was recorded. EC50-24h and EC-48h were calculated by regression analysis using the Probit/log model. The EC50-values of methyl-ethylketone peroxide were 39 mg/L after 24 and 48 hours. The NOEC after 24 hours was 26.7 mg/L.

Description of key information

Methyl-ethylketone peroxide in DMP was assessed in a short-term toxicity to aquatic invertebrates study according to EU-method C.2 and OECD 202. The 48 -hour EC50 of methyl-ethylketone peroxide was 39 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

39 mg/L

Additional information

Methyl-ethylketone peroxide in DMP was assessed in a short-term toxicity to aquatic invertebrates study according to EU-method C.2 and OECD 202. Daphnia magna were exposed in a static test to a concentration range of 7.9 to 60 mg/L. The 24 hour- and 48 -hour EC50 of methyl-ethylketone peroxide was 39 mg/L. The NOEC after 24 hours was 26.7 mg/L.