Hexylamine

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Experimental test result performed using standard test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Principles of method if other than guideline:

Short term toxicity of test chemical to aquatic invertebrate daphnia magna was performed according to the OECD guideline 202 in a static system.

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

The stock solution 100 mg/l was prepared by dissolving colourless liquid in reconstituted water. Test solutions of required concentrationas were prepared by mixing the stock solution of the test sample with reconstituted test water.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain: Straus
- Source: Own breeding at University of Chemistry and Technology, Prague
- Age at study initiation (mean and range, SD): The animals used for the test shall be less than 24 h old and should not be first brood progeny
- Feeding during test: No feeding

ACCLIMATION - No data available
- Acclimation period:
- Acclimation conditions (same as test or not):
- Type and amount of food:
- Feeding frequency:
- Health during acclimation (any mortality observed):

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

± 1 hr

Test temperature:

20±1°C

pH:

Test: 9.2 (changed to 7.9 during test)
Control: 7.7 (change to 7.6 during test)

Dissolved oxygen:

higher than 8 mg/L at the end of test

Nominal and measured concentrations:

0, 1, 2, 4, 8, 16 and 32 mg/l

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 ml glass vessel
- fill volume: 25 ml
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water:
Natural water (surface or ground water), reconstituted water or dechlorinated tap water are acceptable as culturing and dilution water if D. magna survives in it for the duration of the culturing, acclimation and testing without showing signs of stress. Waters in the range pH 6 to pH 9, with hardness between 140 mg/l and 275 mg/l (as CaCO3) are recommended.
As an example, the preparation of dilution water meeting the requirements is described below.
Dissolve known quantities of reagents in water. The dilution water prepared shall have a pH of 7.8 ± 0.5, a hardness of (225 ± 50) mg/l (expressed as CaCO3), a molar Ca + Mg ratio close to 4 + 1 and a dissolved oxygen concentration above 7 mg/l.

Prepare the solutions specified below:
- Calcium chloride solution: Dissolve 117.6 g of calcium chloride dihydrate (CaCl2.2H2O) in water (4.2) and make up to 1 l with water (4.2).
- Magnesium sulfate solution: Dissolve 49.3 g of magnesium sulfate heptahydrate (MgSO4.7H2O) in water (4.2) and make up to 1 l with water (4.2).
- Sodium bicarbonate solution: Dissolve 25.9 g of sodium bicarbonate (NaHCO3) in water (4.2) and make up to 1 l with water (4.2).
- Potassium chloride solution: Dissolve 2.3 g of potassium chloride (KCI) in water (4.2) and make up to 1 l with water (4.2).

Mixing
Mix 2.5 ml of each of the four solutions and make up to 1 l with water.
The dilution water shall be aerated until the dissolved oxygen concentration has reached saturation and the pH has stabilized. If necessary, adjust the pH to 7.8 ± 0.5 by adding sodium hydroxide (NaOH) solution or hydrochloric acid (HCI). The dilution water prepared in this way shall not be further aerated before use.

- Sodium hydroxide solution, e.g. [NaOH] : 1 mol/l.
- Hydrochloric acid, e.g. [HCl] : 1 mol/l.

Reference substance:
Dissolve 600 mg of potassium dichromate (K2Cr2O7) in water and make up to 1 l with water (4.2).

OTHER TEST CONDITIONS
- Adjustment of pH: no adjustment done
- Photoperiod: No - Darkness
- Light intensity:

CALCULATION:
EC50 was calculated using non linear regression by the software Prism 4.0

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7)

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

11.8 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95 % CI was 8.1 - 17.1 mg/l

Results with reference substance (positive control):

- Results with reference substance valid
- EC50: 0.76 mg/L (24 hours)

Reported statistics and error estimates:

EC50 was calculated using non linear regression by the software Prism 4.0

Validity criteria fulfilled:

yes

Conclusions:

Based on the immobility of daphnia magna after the exposure period of 48 hrs with the test chemical, the EC50 was observed at 11.8 mg/l.

Executive summary:

Aim of this study was to assess the short term toxicity of test chemical to aquatic invertebrate daphnia magna. Study was performed according to the OECD guideline 202 in a static system for the total exposure period of 48 hrs. The stock solution 100 mg/l was prepared by dissolving colourless liquid in reconstituted water. Test solutions of required concentration as were prepared by mixing the stock solution of the test sample with reconstituted test water. 0, 1, 2, 4, 8, 16 and 32 mg/l concentration were prepared. Effects on immobilisation were observed for 48 hours. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. The median effective concentration (EC50) for the test substance in Daphnia magna was determined to be 11.8 mg/L on the basis of mobility inhibition effects in a 48 hour study. Based on the EC50 value, chemical was consider as toxic and classified in aquatic chronic 3 category as per the CLP classification criteria.

 

Description of key information

Aim of this study was to assess the short term toxicity of test chemical n- hexylamine (CAS 111-26-2) to aquatic invertebrate daphnia magna. Study was performed according to the OECD guideline 202 in a static system for the total exposure period of 48 hrs. The stock solution 100 mg/l was prepared by dissolving colourless liquid in reconstituted water. Test solutions of required concentration as were prepared by mixing the stock solution of the test sample with reconstituted test water. 0, 1, 2, 4, 8, 16 and 32 mg/l concentration were prepared. Effects on immobilization were observed for 48 hours. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. The median effective concentration (EC50) for the test substance in Daphnia magna was determined to be 11.8 mg/L on the basis of mobility inhibition effects in a 48 hour study. Based on the EC50 value, chemical n- hexylamine (CAS 111-26-2)

was consider as toxic and classified in aquatic chronic 3 category as per the CLP classification criteria.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

11.8 mg/L

Additional information

Various short term studies available for the test chemical n- hexylamine (CAS No. 111 -26 -2) were reviewed to determine the toxic nature of test chemical on the mobility of aquatic invertebrates. The studies are as mentioned below:

In the first key experimental study toxicity were measured. Aim of this study was to assess the short term toxicity of test chemical to aquatic invertebrate daphnia magna. Study was performed according to the OECD guideline 202 in a static system for the total exposure period of 48 hrs. The stock solution 100 mg/l was prepared by dissolving colourless liquid in reconstituted water. Test solutions of required concentration as were prepared by mixing the stock solution of the test sample with reconstituted test water. 0, 1, 2, 4, 8, 16 and 32 mg/l concentration were prepared. Effects on immobilization were observed for 48 hours. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. The median effective concentration (EC50) for the test substance in Daphnia magna was determined to be 11.8 mg/L on the basis of mobility inhibition effects in a 48 hour study. Based on the EC50 value, chemical was consider as toxic and classified in aquatic chronic 3 category as per the CLP classification criteria.

 

Similar study was also conducted which supports the classification of chemical. In a 24 hrs short term toxicity study the effect of test chemical was evaluated on Daphnia magna. The substance was test in a concentration of 20 mg/l (11-42 mg/l). The results show 50% immobility of test organism population at given concentration. Therefore, chemical considered to be toxic at 20 mg/l when tested on Daphnia magna for 24 hrs. Based on the result, chemical was considered to be classified in aquatic chronic category 3 as per CLP classification criteria.

 

Thus based on the above results, chemical consider to be toxic and classified as aquatic chronic category 3 as per the CLP classification criteria.