Aluminium tributanolate

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to microorganisms

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1980

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study well documented, meets generally accepted scientific principles, acceptable for assessment. However no guideline was followed.

Qualifier:

no guideline followed

Principles of method if other than guideline:

Cell multiplication inhibition test:
The presence of a toxic substance in dissolved water inhibits the cell division of the bacteria. Therefore, under identical conditions, the increase of the cell count of a test culture containing dissolved toxic substances will be less than the increase of the cell count in a test culture free from toxic substance. The concentration of the bacterial suspension was measured turbidimetrically (extinction of the primary light of the monochromatic radiation at 436 nm for a layer of 10 mm thickness). The toxicity threshold is defined as the concentration at which the mean extinction value is 3% below the mean value of the extinction value for the control test cultures (non-toxic dilutions) at the end of the test period.

GLP compliance:

no

Remarks:

Study performed before the introduction of GLP

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

Pseudomonas putida

Details on inoculum:

Stock cultures of the test strain, Pseudomonas putida, were kept on the nutrient in agar slant tubes and incubated at 25°C for 24h. The cultures were maintained by inoculating freshly prepared and sterilized agar slant tubes at intervals of one week each. Preliminary cultures were prepared in the same way and kept under the same conditions for 24h. The cells were then washed off with sterile saline and the bacterial suspension were diluted once more with sterile saline to obtain final suspensions presenting a turbidity value corresponding to the extinction value of the Formazin standard suspension TE/F/578 nm=10.

Test type:

static

Limit test:

no

Total exposure duration:

16 h

Test temperature:

25°C

Details on test conditions:

Stock cultures of the test strain, Pseudomonas putida, were kept on the nutrient in agar slant tubes and incubated at 25°C for 24h. The cultures were maintained by inoculating freshly prepared and sterilized agar slant tubes at intervals of one week each. Preliminary cultures were prepared in the same way and kept under the same conditions for 24h. The cells were then washed off with sterile saline and the bacterial suspension were diluted once more with sterile saline to obtain final suspensions presenting a turbidity value corresponding to the extinction value of the Formazin standard suspension TE/F/578 nm=10.

An initial solution of n-butanol was prepared, neutralised if required. Four parallel dilutions from the initial solution of the substance, sewage, or sterile double distilled water, were prepared in 300 ml flasks stoppered with cotton-lined plastic caps. The first flask contained 160 ml of the initial solution containing the test substance. Subsequent dilutions were prepared from this first flask using a constant dilution ratio of 80 ml preliminary n-butanol (or sewage, or sterile double distilled water) dilution with 80 ml of double-distilled water. Each flask contained 40ml of liquid and were completed with 5 ml of the stock solution , 5 ml of the stock solution 2 and inoculated with 10 ml of bacterial suspension mentioned above (preliminary cultures). Blank solutions (controls) were prepared by adding 5 ml of the stock solution 1, 5ml of the stock solution 2 and 10 ml of sterile saline to 80 ml of the liquid containing the different concentrations of the test susbstance. After 16 hours of incubation at 25 °C, samples were taken and the turbidity or the extinction of the monochromatic radiation at 436nm was measured against blanks.

Duration:

16 h

Dose descriptor:

other: TT

Effect conc.:

650 mg/L

Nominal / measured:

nominal

Basis for effect:

growth inhibition

Details on results:

Toxicity threshold (TT) obtained in a cell multiplication inhibition test for Pseudomonas putida.

For the graphic evalutation of the results, the mean value (A) of the extinction for the test cultures free from both toxic influence and stimulation of growth (with the exception of those having extinction values outside a standard deviation of < 3%) and the mean value (B) for the extinction for the test cultures having the lowest toxic pollutant concentration within the dilution series were calculated at the end of the test period.

For mathematical evaluation, the highest non-toxic poIlutant concentration (a) was plotted against (A) and the lowest toxic pollutant concentration (b) was plotted against (B) as coordinates in a semi-logarithmic coordinate system. With the assumption that a negative deviation of the mean extinction by a 3% difference against the mean extinction value for all test cultures having a non toxic and non-stimulating pollutant concentraion may be used as an inicator of the beginning of inhibitory action, the pollutant concentration at which the inhibitory effect was beginning (c) was deduced from the regression line between (a; A) and (b;B) using the extinction value (A-3%) as ordinate.

Validity criteria fulfilled:

not specified

Conclusions:

The following result was determined for 1-butanol (species: Pseudomonas putida): TT(16h)= 650 mg/L.

Executive summary:

Toxicity threshold for 1-butanol was determined for the bacterial strain Pseudomonas putida by a cell multiplication inhibition test. The toxicity threshold concentration (greater or equal 3% lower measured light extinction in cell suspension in comparison to control) can therefore be interpreted as an EC03 value which represents a worst-case for a EC10 value. The following result was determined for 1-butanol (species: Pseudomonas putida): TT(16h)= 650 mg/L.

Reference 2

Endpoint:

toxicity to microorganisms, other

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

ISO 10712 (Water quality – Pseudomonas putida growth inhibition test (Pseudomonas cell multiplication inhibition test

Version / remarks:

ISO 107122-1994 Water quality – Pseudomonas putida growth inhibition test
(Pseudomonas cell multiplication test).

GLP compliance:

not specified

Remarks:

Information on GLP is not reported. Quality of the report implies that GLP conditions were met.

Specific details on test material used for the study:

purity > 98%

Analytical monitoring:

no

Vehicle:

yes

Details on test solutions:

test solutions were prepared in water and sonicated for 30 minutes to prevent aggregation. Further dilutions were prepared in according to ISO 107122-1994

Test organisms (species):

Pseudomonas putida

Details on inoculum:

- Laboratory culture: laboratory activated sludge (Department of Biology, Faculty of Building Services, Hydro and Environmental Engineering, Warsaw University of Technology)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

16 h

Test temperature:

26°C

Nominal and measured concentrations:

0.17 to 200 mg/L (serial dilution with factor 2)

Details on test conditions:

TEST SYSTEM: no details provided according to guidline

TEST MEDIUM / WATER PARAMETERS accoding to the guideline

Duration:

16 h

Dose descriptor:

EC50

Effect conc.:

295.7 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Remarks on result:

other: 156.5 mg/L as Al

Duration:

16 h

Dose descriptor:

NOEC

Effect conc.:

1.9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Remarks on result:

other: 1.0 mg/L as Al

Details on results:

the results of the nano material indicated an increased toxicity with an EC50 of 0.5 mg/L and a NOEC of 0.19 mg/L

Reported statistics and error estimates:

Effective concentrations (EC50) were calculated using probit analysis with 95% confidence intervals [25]. No observed effect concentrations (NOEC) were determined using ANOVA and Tukey’s test

Validity criteria fulfilled:

not specified

Conclusions:

The EC50 of aluminium oxide in pseudonomas putida is 295 mg/L (165.5 mg/L as Al)

Executive summary:

In a standard test in pseudonomas putida, the bacteria were exposed to concentrations of alumium hydroxide between 0.17 and 200 mg/L for 16 hours. Effects on bacterial growth became apparent above 1.9 mg/L. The EC50 is 295 mg/L (165.5 mg/L as Al)

Description of key information

Aluminium tributanolate dissociates instantaneously when exposed to water forming butan-1-ol and soluble aluminium(III) species. Therefore the effects of both hydrolysis products are considered most relevant to assess the toxicity of aluminium tributanolate.

In a standard test in pseudomonas putida, the bacteria were exposed to concentrations of aluminium hydroxide between 0.17 and 200 mg/L for 16 hours. Effects on bacterial growth became apparent above 1.9 mg/L. The EC50 is 295 mg/L (165.5 mg/L as Al) (Doskocz 2017).

Toxicity threshold for 1-butanol was determined for the bacterial strain Pseudomonas putida by a cell multiplication inhibition test during 16 hours to be 650 mg/L (Bringmann 1980)

Key value for chemical safety assessment

EC50 for microorganisms:

165 mg/L

Additional information

Aluminium tributanolate reacts instantaneously with water to form butan-1-ol and Al3+ species. The resulting pH being weakly alkaline indicates according to Langmuir et al. 2004 that Al3+ species formed are mainly Al(OH)4-, Al(OH)3 and Al(OH)2+ at pH 8.5.

Aluminium tributanolate is abiotically degradable and forms butanol being readily biodegradable as shown in several publications (Bridie 1979, Price 1974).

Hence, both butanol and aluminium species will be present in aqueous media. Based on its toxicity, aluminium species seem to represent a worst case surrogate for assessing toxicity to aquatic species exposed to the substance, aluminium tributanolate.