Diisodecyl azelate

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to microorganisms

Type of information:

experimental study

Adequacy of study:

key study

Study period:

20 Dec 1993

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

non-GLP

Qualifier:

according to guideline

Guideline:

DIN 38412-8 (Pseudomonas Zellvermehrungshemmtest)

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The test solution was prepared according to the national standard procedure (DEV S4): 20 g of the test substance was added to deionised water and shacked overhead for 24 h. This solution was filtered with a folded filter. The filtrate was used for the test. It was added directly to the test vessels and diluted with deionised water to the desired concentration.

Test organisms (species):

Pseudomonas putida

Details on inoculum:

- Laboratory culture: A preculture was incubated for 7 h before test initiation at 21 °C.
- Preparation of inoculum for exposure: The preculture was diluted with sterile growth medium to obtain a turbidity of 50 TE/F436. 10 mL was inoculated to 50 mL eluate of the test substance and 10 mL of growth medium. This mixture was filled up with deionised water to a total volume of 100 mL.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

16 h

Remarks on exposure duration:

± 1h

Test temperature:

21 ± 1 °C

Nominal and measured concentrations:

Nominal concentration: 10000 mg/L filtered test solution

Details on test conditions:

TEST SYSTEM
- Test vessel: conical flasks
- size, fill volume: 300 mL, 100 mL
- Aeration: incubated on a shaker (Braun Certomat R)
- No. of vessels per concentration: 3
- No. of vessels per control: 3

EFFECT PARAMETERS MEASURED: Growth inhibition was measured after 16 h test duration.

TEST CONCENTRATIONS
- Justification for using less concentrations than requested by guideline: Because the test substance is poorly water soluble the filtrate from a stock solution of 10 g/L was used to analyse if there are any effects in the range of water solubility.

Reference substance (positive control):

no

Duration:

16 h

Dose descriptor:

EC10

Effect conc.:

> 10 g/L

Nominal / measured:

nominal

Conc. based on:

other: filtered test solution

Basis for effect:

growth inhibition

Duration:

16 h

Dose descriptor:

EC50

Effect conc.:

> 10 g/L

Nominal / measured:

nominal

Conc. based on:

other: filtered test solution

Basis for effect:

growth inhibition

No effects of the test substance in the range of water solubility were observed testing a saturated test solution which was subsequently filtered. Thus, an LC50 (16h) greater then the highest tested concentration of 10 g/L is determined.

Description of key information

EC10 (16 h) > 10000 mg/L (nominal) for growth rate of P. putida (DIN 38412, part 8).

Additional information

The toxicity of Diisodecyl azelate (CAS 28472-97-1) to Pseudomonas putida was investigated in one study (Institut für gewerbliche Wasserwitschaft und Luftreinhaltung e.V., 1993). The test substance is described as an unknown, variable composition, complex reaction product or biological material (UVCB) under REACH. The study was performed according to DIN guideline 38412, part 8 “Pseudomonas-Cell Growth Inhibition Test”. A single test concentration of 10 g/L was chosen to evaluate the growth inhibition after 16 h. No growth inhibition of P. putida was reported, the EC10 thus beeing greater than 10 g/L. In addition, the toxicity control of an OECD 301B test showed no inhibition at a test substance concentration of 13 mg/L (Roulstone, 2014; please see technical dossier chapter 5.2.1 for further details). Therefore disturbances in the biodegradation process of sewage treatment plants are not anticipated for Diisodecyl azelate.