2-propanol and 2-butanol production, distn. residues

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:

1 November - 5 November 2010

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

The content of the test item in the test vessels was measured every 24 hours during the study. Samples were taken after preparation of the treatments at the start of the test and at the end of the test and were filtrated with membrane filters (pore diameter 0.45 µm). The samples were measured directly. Each sample was measured at least in duplicate.

Vehicle:

no

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebrafish
- Strain: HAMILTON-BUCHANAN
- Source: Dehner Garten Center, 67433 Neustadt
- Age at study initiation (mean and range, SD): sexually immature young fish
- Length at study initiation (length definition, mean, range and SD): 2 ±1 cm
- Feeding during test: no

ACCLIMATION
- Acclimation period: 14 days
- Acclimation conditions (same as test or not): same as test
- Type and amount of food: warmwater fishfood and daphnia
- Feeding frequency: three times a day
- Health during acclimation (any mortality observed): During this period, mortality didn’t surpass 5%

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Test temperature:

21.7 - 22.9

pH:

pH 8.1 - 8.5 (in control: 7.8 - 8.4)

Dissolved oxygen:

8 - 10 (in control: 7.7 - 9.6)

Nominal and measured concentrations:

Nominal and measured concentrations: See table "Any other information on materials and methods incl. tables"

Details on test conditions:

General Conditions

24 hours before the start of the test, food was withheld from the designated test fish.
Each day before medium renewal, a stock solution containing 175 mg/L test item was pre-pared. This solution was used to prepare the concentration to be tested.
Date: 01. – 05. Nov. 2010
Treatment 41 mg/L
Replicates: one vessel, each containing test solution and 7 fish
Control: one vessel, containing dilution water and 7 fish
Test Design semi-static, closed system
Medium renewal every 24 ±1 hours
Duration 96 hours
Loading 1 fish/L
Vessels: glass aquaria, maximal volume 10 L
Aeration: accomplished with glass tubes, frequency of bubbles 1/s
Feeding: none
Photo period: 12/12 hours using neon tubes
Temperature: 23 ±2 °C (deviation within on test ±1 °C)
pH adjustment: none
Observations were made every 24 hours, measuring pH and O2-concentration of the old and new test solution in each vessel and documenting mortalities or abnormal behaviour. The content of the test item in the test vessels was measured every 24 hours during the study.
A fish was considered dead, if no visible movement could be observed, and if touching of the caudal peduncle produced no reaction.


Due to the volatility of the test item, the nominal load of the test item as determined in non-GLP pre-tests (1.8 mL) was directly injected into 2 L Schott flasks, filled with 2 L dilution water. Then, the vessels were immediately closed and stirred on a magnetic stirrer for 24 hours. The resulting solution was added to the aquaria filled with 11.5 L diluted water. Then, the nearly completely filled aquaria were covered with a glass plate. One day before the start of the study and every 24 hours during the test, the test solution was prepared freshly.

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

71 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

dissolved

Remarks:

organic carbon

Basis for effect:

mortality (fish)

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

> 71 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

dissolved

Remarks:

organic carbon

Basis for effect:

mortality (fish)

Duration:

24 h

Dose descriptor:

LC100

Effect conc.:

> 71 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

dissolved

Remarks:

organic carbon

Basis for effect:

mortality (fish)

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

71 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

dissolved

Remarks:

organic carbon

Basis for effect:

mortality (fish)

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

> 71 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

dissolved

Remarks:

organic carbon

Basis for effect:

mortality (fish)

Duration:

48 h

Dose descriptor:

LC100

Effect conc.:

> 71 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

dissolved

Remarks:

organic carbon

Basis for effect:

mortality (fish)

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

71 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

dissolved

Remarks:

organic carbon

Basis for effect:

mortality (fish)

Duration:

72 h

Dose descriptor:

LC50

Effect conc.:

> 71 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

dissolved

Remarks:

organic carbon

Basis for effect:

mortality (fish)

Duration:

72 h

Dose descriptor:

LC100

Effect conc.:

> 71 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

dissolved

Remarks:

organic carbon

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

71 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

dissolved

Remarks:

organic carbon

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 71 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

dissolved

Remarks:

organic carbon

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

> 71 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

dissolved

Remarks:

organic carbon

Basis for effect:

mortality (fish)

Sublethal observations / clinical signs:

Mortalities

The mortalities were recorded daily and can be found in the following table.

Table 1 Mortalities

Nom. Conc. in mg/L	Total of fish used	dead fish
		24 h		48 h		72 h		96 h
		new	cum.	new	cum.	new	cum.	new	cum.
0	7	0	0	0	0	0	0	0	0
101	7	0	0	0	0	0	0	0	0

 

No abnormal behaviour of the surviving fish was observed.

 

 pH and O₂-Values, Temperature

The pH values in the test media and the control ranged from 7.8 to 8.5. The concentration of dissolved oxygen stayed above 7.7 mg/L or 90% throughout the test. Temperature range was 21.7 – 22.9 °C. The details are given in the following tables:

Table 2a    pH values

Nominal Concentration in mg/L	pH at t in h (old/new test solution)
	0 h	24 h		48 h		72 h		96 h
	new	old	new	old	new	old	new	old
0	8.3	8.0	8.2	8.1	8.4	7.9	8.3	7.8
101	8.2	8.0	8.3	8.1	8.5	8.1	8.4	8.1

 

Table 2b     O₂ Values

Nominal Concentration in mg/L	O2in mg/L at t in h (old/new test solution)
	0 h	24 h		48 h		72 h		96 h
	new	old	new	old	new	old	new	old
0	9.4	8.0	9.4	8.5	9.4	8.4	9.6	7.7
101	9.4	8.0	9.4	9.0	9.4	9.0	10.0	8.7

 

Table 2c     Temperature

0 h	24 h	48 h	72 h	96 h
22.8	22.9	21.7	21.9	22.1

Validity criteria fulfilled:

yes

Conclusions:

The following results were determined for the test item reaction mass of "2-propanol and 2-butanol production, distn. residues" (main constituents 2,2'-oxybisbutane (DSBE), DIPE, SBA and 2-methylpropan-2-ol (TBA)) (species: Danio rerio): 24h, 48h, 72h and 96h-NOEC = 71 mg/L; 24h, 48h, 72h and 96h-LC50 >71 mg/L; 24h, 48h, 72h and 96h-LC100 > 71 mg/L. Up to a nominal concentration of 100 mg/L the test substance showed no mortality to zebrafish.

Executive summary:

The 96h-LC50 of reaction mass of "2-propanol and 2-butanol production, distn. residues" (main constituent 2,2'-oxybisbutane (DSBE), DIPE, SBA and 2 -methylpropan-2 -ol (TBA)) were determined for Danio rerio according to OECD 203 resp. EU C.1.

Due to the volatility, of the test item the toxicity against Danio rerio was tested using a semi-static test design in closed vessels. The main study was performed as a limit test at nominal concentration 101 mg/L (corresponding to a threshold approach concentration of 41 mg/L, lowest EC 50 in alga and daphnia test). The necessary nominal load of test item based on the density of the test item (0.76 g/ml), the content of organic carbon of 76 % and recovery rates of DOC measurements was determined in non-GLP pre-tests. Therefore, the test solutions were prepared in higher concentrations than the threshold concentration (101 mg/L instead of 41 mg/L).

Seven fish were exposed to the test item for 96 hours in a semi-static test design. The treatment showed no mortality.

At the beginning and every 24 hours during the test, the content of test item was determined by calculation from content of organic carbon of the test item (76%) and TOC-determination in the new and old test solutions. The geometric mean of the measured concentrations was used for the determination of the biological results.

The following results for the test item reaction "2-propanol and 2-butanol production, distn. residues" could be determined:

96h NOEC = 71 mg/L

96h LC50 > 71 mg/L

Description of key information

The following results were determined for the test item "2-propanol and 2-butanol production, distn. residues" (species: Danio rerio): 24h, 48h, 72h and 96h-NOEC = 71 mg/L; 24h, 48h, 72h and 96h-LC50 >71 mg/L; 24h, 48h, 72h and 96h-LC100 > 71 mg/L.

The treatment showed no mortality.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

71 mg/L

Additional information

The LC50 value and the NOEC for the mortality of Danio rerio of "2-propanol and 2-butanol production, distn. residues" was measured according to OECD 203, respectively EU C.1 guideline under GLP. Following results were obtained: 96h-NOEC = 71 mg/L; 96h-LC50 = > 71 mg/L

The measured concentrations were higher than the nominal concentration. As no mortality occurred, this is stated as uncritical. The analytical determinations of the test item showed good correlation between old and new test solutions. The determination of the results was based on the geometric mean of the concentrations.

The treatment showed no mortality to Danio rerio.