Decan-1-ol

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to microorganisms, other

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1980

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

secondary literature

Remarks:

This information was obtained from the public IUCLID 2000 CD-ROM. Further review of the original source, to reassess the reliability, would not alter the overall conclusions concerning this end point.

Principles of method if other than guideline:

Method: other: Test for inhibition of spore germination

Test organisms (species):

other: other fungi: see remarks

Duration:

20 h

Dose descriptor:

EC0

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

other:

Basis for effect:

other: Inhibition of spore germination

Remarks on result:

other: No toxic effects following 20 h exposure (Candida albicans, Mucor mucedo; 37 degr. C; pH 5.6)

Duration:

5 d

Dose descriptor:

EC0

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Inhibition of spore germination

Remarks on result:

other: No toxic effects following 5 d exposure (Aspergillus niger, Trichophyton mentagrophytes, Myrotecium verrucaria; 28 degr. C; pH 5.6)

Duration:

5 d

Dose descriptor:

LOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Inhibition of spore germination

Remarks on result:

other: Antifungal activity at all concentrations tested (Trichoderma viride, lowest tested concentration: 100 mg/l; 28 degr. C; pH 5.6)

Reference 2

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1999

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to an appropriate national standard method. It was not compliant with GLP.

Principles of method if other than guideline:

Method: other

GLP compliance:

not specified

Analytical monitoring:

not specified

Test organisms (species):

Pseudomonas putida

Duration:

30 min

Dose descriptor:

EC0

Effect conc.:

10 000 mg/L

Reference 3

Endpoint:

toxicity to microorganisms, other

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1990

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: This information was obtained from the public IUCLID 2000 CD-ROM. Further review of the original source, to reassess the reliability, would not alter the overall conclusions concerning this end point.

Principles of method if other than guideline:

Method: other: static test

Test organisms (species):

Tetrahymena pyriformis

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

8.83 mg/L

Reference 4

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

disregarded due to major methodological deficiencies

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: This information was obtained from the public IUCLID 2000 CD-ROM. Further review of the original source, to reassess the reliability, would not alter the overall conclusions concerning this end point.

Test organisms (species):

other: other bacteria: mixed microbial culture

Duration:

75 min

Dose descriptor:

EC50

Effect conc.:

0.003 mol/L

Reference 5

Endpoint:

toxicity to microorganisms, other

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1978

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: This information was obtained from the public IUCLID 2000 CD-ROM. Further review of the original source, to reassess the reliability, would not alter the overall conclusions concerning this end point.

Test organisms (species):

Bacillus subtilis

Dose descriptor:

EC50

Effect conc.:

0.3 mmol/L

Description of key information

Inhibition of WWTP microorganisms (decan-1-ol): no significant inhibitory effects on respiration of activated sludges or specific microbial strains relevant to WWTP, at or above the limit of solubility (based on inhibition tests and lack of toxicity in ready biodegradability test).

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

10 000 mg/L

Additional information

In accordance with Column 2 of REACH Annex VIII, the activated sludge respiration inhibition study (required in Section 9.1.4 of REACH) does not need to be conducted as the substance is readily biodegradable and the applied test concentrations are in the range that can be expected in the influent to a sewage treatment plant.

A key study conducted with decan-1-ol reported a 30-miute EC0 value of 10000 mg/L for the effects of the test substance on the oxygen consumption rate ofPseudomonas putida, based on nominal concentrations (Henkel, 1999). The EC0 and therefore the EC50 value is greater than the limit of solubility of decan-1-ol (approximately 37 mg/L). The study was conducted according to DIN 38412 part 27 and assigned a reliability value of 2. This is supported by results of non-assignable reliability indicating EC50 443 mg/l for respiration of a mixed microbial culture.

This is supported by results of non-assignable reliability studies with shorter chain-lengths within the C6 -24 Alcohols Category, indicating EC50 in the hundreds of mg/l (in some cases, up to and exceeding the limit of solubility) for respiration of a mixed microbial culture. Additionally, consistent results (ECx >= 10000 mg/l) are reported in the public domain for tetradecanol and C12 -14 mixed alcohols, although original studies were not available from the data owner.

 

Discussion of trends in the Category of C6-24 linear and essentially-linear aliphatic alcohols:

 

A number of studies of the toxicity of LCAAs to single species of micro-organisms have been identified. A range of results are shown in Table 7.21 of the Category CSR, for test species relevant to WWTP (studies on various other organisms are also available).

 

The ready biodegradation studies (Federle, 2009 and Flach, 2012, discussed in Section 5.2.1) gives evidence that rapid biodegradation by aquatic activated sludge microorganisms is seen, even in the presence of an excess of test substance (for the longer chain length category members tested). It is notable that the biodegradation in the ready test was very high compared to ThCO₂, indicating that over the course of the test the exposure of organisms to test substance must have been complete.

 

At or above the limit of solubility, the data set shows that the alcohols in the chain length range C6-24 category have no significant inhibitory effects on respiration of activated sludges or specific microbial strains relevant to WWTP. There is limited evidence of inhibition of growth in some specific microbial strains but ready biodegradation evidence suggests this is not significant for mixed populations.

The reliability of some of these data individually is not high, but it presents a consistent weight of evidence.

 

In general it can be said that the micro-organisms examined in these tests were less susceptible to the LCAAs than fish, invertebrates and algae and that in general, IC₅₀ values for respiration effects are at or significantly above the limit of water solubility.

 

WWTP microorganisms have been demonstrated to be capable of synthesising significant concentrations of aliphatic alcohols (e.g. Mudge et al., 2008).