Isopropylamine

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:

18.04.1988 - 20.04.1988

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Non GLP-guideline study without analytical monitoring

Qualifier:

according to guideline

Guideline:

other: EU-method C.2 (1984)

Deviations:

yes

Remarks:

Daphnia were 2-24h old in the test instead of > 6 < 24h as as required by the guideline

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna Straus

- Source: Institut National de Recherche Chimique Appliquee, France; since 1978 maintained in the Laboratory for Environmental Analytics and Ecology at BASF AG Ludwigshafen

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

none

Hardness:

water-hardness: 2.8 mmol/L

Test temperature:

20-22 °C (292-294 K)

pH:

range of pH at start: 8.4 (1.95 mg/L) - 10.95 (250 mg/L);
range of pH after 48 h: 7.94 (3.9 mg/L) - 9.06 (250 mg/L)

Dissolved oxygen:

range of O2 (mg/L) at start: 8.44 (3.9 mg/L) - 8.6 (control);
range of O2 (mg/L) after 48 h: 7.98 (62.4 mg/L) - 8.39 (250 mg/L)

Nominal and measured concentrations:

- test concentrations: 1.95, 3.9, 7.8 15.6, 31.2, 62.4, 125, 250 mg/L (nominal)

Details on test conditions:

TEST MEDIUM / WATER PARAMETERS
Test conditions:
- dilution water: source: tap water;
pretreatment steps:
(1) 6 µm- and charcoal-filtration
(2) H2SO4 was added to reduce alkalinity up to pH 4.3
(3) distilled water was added to reduce water-hardness
(4) water was aerated (oil-free air) until saturated with oxygen
(5) water was stored for at least 24 h for stabilization.

Specifications measured at test start:
- test temperature: 20-22 °C (292-294 K)
- water-hardness: 2.8 mmol/L
- alkalinity up to pH 4.3: 0.83 mmol/L
- pH: 8.0,
- conductivity: 640 µSiemens/cm
- water solubility: >500 mg/L at 21 °C (293 K)

TEST SYSTEM
- test vessels: test tubes (glass) with flat bottom (nominal volume 20 ml)
- test volume: 10 ml
- volume/animal: 2 ml
- number of animals/vessel: 5
- replicates: 4 per concentration
- total number of animals/conc.: 20
- Age of organisms at test start: 2-24 h
- observation times: visually after 0, 3, 6, 24 and 48 h
- observation parameters: swimming ability, pH, oxygen
- test was performed in non-sealed vessels
- illumination: diffuse light

Reference substance (positive control):

not specified

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

31.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

47.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% C.L. = 41.58 - 53.96 mg/L

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

125 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Effect values after 48h:
EC0 = 31.2 mg/L
EC50 = 47.37 mg/L 95 % confidence limits: 41.58 - 53.96 mg/L
EC100 = 125 mg/L

Effect values after 24 h:
EC0 = 31.2 mg/L
EC50 = 49.04 mg/L 95 % confidence limits: 43.87 - 54.81 mg/L
EC100 = 125 mg/L

Mortality of control: 0 %

Validity criteria:
1) In the control not more than 10 per cent of the daphnids have been immobilised;
2) Dissolved oxygen concentration at the end of the test has not been lower than 3 mg/L in control and test vessels.

Results with reference substance (positive control):

no data

Reported statistics and error estimates:

See IUCLID section "Any other information on materials and methods incl. tables" above.

Number of mobile test animals after exposure (48h) to various test concentrations:
concentration (mg/L)  mobile Daphnids
      1.95		20
      3.9		20
      7.8		20
     15.6		20
     31.2		19  
     62.4		 3
    125.0		 0
    250.0		 0
   control		20

Remarks in the report: 
Toxicity at 62.5 - 250 mg/L may be due to the high pH (up to 10.95)

Validity criteria fulfilled:

yes

Remarks:

Immobilization in control <10% and O2 >2 mg/L at the end of the test

Conclusions:

48h-EC50 (Daphnia magna, immobilisation; static) = 47.37 mg/L (nominal)

Executive summary:

Mobility inhibition of Daphnia magna has been investigated according to EU-method C.2 (1984).

In a static test design (no medium change during the entire exposure duration), Daphnia magna were exposed for 48h to an aqueous solution of isopropylamine at nominal concentrations of 1.95 - 3.9 - 7.8 - 15.6 - 31.2 - 62.4 - 125 and 250 mg/L.

The validity criteria (as stated in EU-method C.2, 1984) are fulfilled. No chemical analysis of the test item concentrations was performed (not required according to EU-method C.2, 1984). However, based on the very high water solubility of the compound (miscible in a 1 : 1 ratio mixture (w/w) with water (at 20°C)), the very low adsorption potential (read across with n-butylamine (source): experimentally determined Koc from batch-equilibrium test: approx. 43.2 L/kg) and being not volatile (fully ionized at environmental pH) it may be assumed with high confidence that the test item was stable during the test.

Taking all information given into account,the study was considered reliable and adequate for the environmental hazard assessment.

Results:

At the lower test item concentrations applied (1.95, 3.9, 7.8 and 15.6 mg/L), no immobility was observed after 48 h of the test. At the concentration 31.2 mg/L 1/20 daphnia were immobile and at 62.4 mg/L 17/20 daphnia were immobile. At 125 and 250 mg/L, immobility was 100%. The 48h-EC50 was identified as 47.37 mg/L (95% C.L: 41.58 - 53.96 mg/L). The 48h-EC0 is 31.2 mg/L.

Manifestation of symptoms went in line with significantly elevated pH values (62.5 mg/L test item concentration and higher); immobility at 62.5 - 250 mg/L was identical after 24h and 48h. This is indicative for pH-induced toxicity at 62.5 - 250 mg/L (pH 10.17-10.95 at test start; 8.6-9.06 at test end). The alkaline pH could have contributed or even have been causative for observed toxicityat 62.5 - 250 mg/L. The derived EC50 may therefore be regarded as conservative.

Description of key information

Daphnia magna: EC50(48h; nominal) = 47.4 mg/L; EC0(48h; nominal) = 31.2 mg/L;

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

47.4 mg/L

Additional information

A valid standard test with Daphnia magna showed 48h EC0 and EC50 values of 31.2 and 47.4 mg/L, respectively.

No data is available on marine species. It is assumed that marine species respond without substantial difference from daphnia.

Key study:

Mobility inhibition of Daphnia magna has been investigated according to EU-method C.2 (1984).

In a static test design (no medium change during the entire exposure duration), Daphnia magna were exposed for 48h to an aqueous solution of isopropylamine at nominal concentrations of 1.95 - 3.9 - 7.8 - 15.6 - 31.2 - 62.4 - 125 and 250 mg/L.

The validity criteria (as stated in EU-method C.2, 1984) are fulfilled. No chemical analysis of the test item concentrations was performed (not required according to EU-method C.2, 1984). However, based on the very high water solubility of the compound (miscible in a 1 : 1 ratio mixture (w/w) with water (at 20°C)), the very low adsorption potential (read across with n-butylamine (source): experimentally determined Koc from batch-equilibrium test: approx. 43.2 L/kg) and being not volatile (fully ionized at environmental pH) it may be assumed with high confidence that the test item was stable during the test. Taking all information given into account, the study was considered reliable and adequate for the environmental hazard assessment.

Results:

At the lower test item concentrations applied (1.95, 3.9, 7.8 and 15.6 mg/L), no immobility was observed after 48h of the test. At the concentration 31.2 mg/L 1/20 daphnia were immobile and at 62.4 mg/L 17/20 daphnia were immobile. At 125 and 250 mg/L, immobility was 100%. The EC50 (48h) was identified as 47.37 mg/L.

Manifestation of symptoms went in line with significantly elevated pH values (62.5 mg/L test item concentration and higher); immobility at 62.5 - 250 mg/L was identical after 24h and 48h. This is indicative for pH-induced toxicity at 62.5 - 250 mg/L (pH 10.17-10.95 at test start; 8.6-9.06 at test end). The alkaline pH could have contributed or even have been causative for observed toxicity at 62.5 - 250 mg/L. The derived EC50 may therefore be regarded as conservative.

Overall conclusion

The EC50 (48h) was 47.37 mg/L in Daphnia magna. Therefore, an EC50 of 47.37 mg/L for aquatic invertebrates serves as a basis for classification and labelling as well as for environmental hazard and risk assessment. The study was performed without adaption of pH (pH 10.17-10.95 measured at test start in the concentrations 62.5 - 250 mg/L). Accordingly, effects could be increased or even caused by the alkaline pH.