Hexadecanedioic acid

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

1990

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Meets National Standard Methods (DIN); non-GLP

Justification for type of information:

1. HYPOTHESIS FOR THE CATEGORY APPROACH (ENDPOINT LEVEL)
Dicarboxylic acids are organic compounds that contain two carboxylic acid functional groups. They have the general type formula HOOC-(CH2)n-COOH. The present defined category comprises dicarboxylic acids with straight carbon chain having a “n” value from 6 to 16.
The physical and chemical properties as well as the toxicology and environmental fate and effects show that substances in this category have a similar order of toxicological and environmental fate properties, which supports the grouping of these substances as a category. (see attached justification)

2. CATEGORY APPROACH JUSTIFICATION (ENDPOINT LEVEL)
There are number of unifying considerations justifying the similarity between these substances in some important aspects. These include:
(1) Similarity of Use: these dicarboxylic acids have several industrial uses in the production of adhesives, plasticizers, lubricants, copolymers (such as polyamides and polyesters), etc.
(2) Similarity of Functional groups: all these substances contain two common functional groups (2 carboxyl groups). The only difference between the substances of this group lies in the length of the carbon chain.
(3) Similarity of Physical / Chemical properties: the similarity of physical / chemical properties for these substances (see attached justification)
(4) Similarity of Metabolism: Dicarboxylic acids were shown to be rapidly absorbed from the gastrointestinal tract, introduced into the fatty acid catabolism and therefore extensively metabolized by the organism and excreted (Passi, S. et al, 1983).
(5) Similarity of Mammalian Toxicity: The constituents of this class have similar toxicological properties. They are not acutely toxic, irritating to skin or sensitizing. However, they all present, except for dodecanedioic acid, irritating effects on the eyes (from moderate to high effects). They do not produce systemic effects in repeated dose studies. They are neither mutagenic nor carcinogenic and do not produce developmental/reproductive toxicity. (see attached justification)
(6) Similarity of Environmental Toxicity and Fate Properties: The substances in this category have similar environmental effects properties. The environmental effects data are similar for most category members in that most members do not exhibit acute toxicity. (see attached justification)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1990

Report date:

1990

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

ISO 8192 (Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation)

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Sebacic acid

EC Number:

203-845-5

EC Name:

Sebacic acid

Cas Number:

111-20-6

Molecular formula:

C10H18O4

IUPAC Name:

sebacic acid

Details on test material:

- Name of test material (as cited in study report): Sebacic Acid
- Substance type: White powder
- Physical state: Solid

Sampling and analysis

Analytical monitoring:

no

Test organisms

Test organisms (species):

activated sludge, domestic

Study design

Test type:

static

Water media type:

freshwater

Test conditions

Details on test conditions:

Type: aquatic

Results and discussion

Effect concentrations

Duration:

3 h

Dose descriptor:

other: EC20

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Any other information on results incl. tables

RS-Freetext:
DOC (calculated) 590 mg/l 

30 min values: 
oxygen consumption (mg02/l*h) 41,3
reference value (mg02/l*h) 39,9
delta (%) 4 
EC20 (determined graphically) > 1000 mg/l 

3h values: 
oxygen consumption (mg02/l*h) 42,3
reference value (mg02/l*h) 36,4
delta (%) 16 
EC20 (determined graphically) > 1000 mg/l

Applicant's summary and conclusion

Validity criteria fulfilled:

not specified

Conclusions:

Under the conditions of the study, the EC20 of the test substance was determined to be >1000mg/L.

Executive summary:

The toxicity to microorganisms of the test substance was evaluated according to ISO 8192 (Test for Inhibition of Oxygen Consumption by Activated Sludge). Under the conditions of the study the EC20 of the test substance was determined to be >1000mg. After incubation of 3 hours no respiration inhibition observed up to the highest test concentration of 1000 mg/L. The inhibition of the degradation activity of activated sludge on sebacic acid is not anticipated when introduced in appropriate low concentrations.