Hexan-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:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

The study was well documented and meets generally accepted scientific principles, but was not conducted in compliance with GLP.

Qualifier:

equivalent or similar to guideline

Guideline:

other: ISO 10712

Principles of method if other than guideline:

Toxicity threshold test in Pseudomonas putida based on cell multiplication

GLP compliance:

not specified

Analytical monitoring:

not specified

Test organisms (species):

Pseudomonas putida

Details on inoculum:

- Laboratory culture: Stock cultures of Pseudomonas putida kept on nutrient medium in agar slant tubes. For onward culturing of the test strain, new stock cultures prepared at intervals of 1 week.

- Preparation of inoculum for exposure: Determine the extinction of the monochromatic radioation at 436 nm for a 10mm layer of the bacterial suspension by photoelectric measurement. On the bases of the values thus measured, adjust the final turbidity value of the bacterial suspension by means of sterile saline in such a way that the extinction value for a measuring sample that has been subject to onward dilution 1 + 9 with saline will correspond to the extinction value of a Formazin standard suspension TE/F/436nm = 10.

Test type:

other: Cell multiplication inhibition test

Water media type:

freshwater

Total exposure duration:

16 h

Remarks on exposure duration:

Incubation period

Test temperature:

25 degC

Details on test conditions:

TEST SYSTEM
- Test vessel: 300 ml Erlenmeyer flasks, stoppered with cotton-lined plastic cups

- Test vessel content: 80ml culture liquid, 5ml stock solution I, 5ml stock solution II, and 10ml each of bacterial suspension (or 10ml each of saline for the dilution series not inoculated)

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Double distilled water

OTHER TEST CONDITIONS
- Adjustment of pH: Pollutant solution neutralised by addition of small amount acid or alkaline solution, in such a way that the volume added is kept as small as possible.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable)
- Concentration of the bacterial suspension measured turbidimetrically, and expressed as extinction of the primary light of monochromatic radiation at 436nm for a layer 10mm thick. The concentration at which the inhibitory action of a pollutant starts will be present in that step of a dilution series of the pollutant having an extinction value at the end of the test period that is ¿3% below the mean value of extinction for non-toxic dilutions of the test cultures.


TEST CONCENTRATIONS
- Spacing factor for test concentrations: Four parallel dilution series, 1:2 to 1:2E+14 v/v. One series inoculated, one not.

Reference substance (positive control):

not required

Remarks:

not applicable

Duration:

16 h

Dose descriptor:

other: TT or EC3

Effect conc.:

62 mg/L

Basis for effect:

other: cell multiplication inhibition

Conclusions:

A toxicity threshold (TT) value for bacteria (Pseudomonas putida) of 62 mg/l was determined in a reliable study conducted according to generally accepted scientific principles.

Reference 2

Endpoint:

toxicity to microorganisms, other

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

The study was well documented and meets generally accepted scientific principles, but was not conducted in compliance with GLP.

Qualifier:

no guideline followed

GLP compliance:

not specified

Analytical monitoring:

not specified

Test organisms (species):

other: other protozoa: Entosiphon sulcatum

Test type:

other: cell multiplication inhibition

Duration:

72 h

Dose descriptor:

other: TT or EC3

Effect conc.:

75 mg/L

Reference 3

Endpoint:

toxicity to microorganisms, other

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

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 endpoint.

Principles of method if other than guideline:

Method: other: not specified

GLP compliance:

not specified

Analytical monitoring:

not specified

Test organisms (species):

Tetrahymena pyriformis

Details on test conditions:

Type: aquatic

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

300.4 mg/L

Reference 4

Endpoint:

toxicity to microorganisms, other

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

The result is sourced from secondary literature (Handbook). The original reference was not available for review and no further information is available.

Test organisms (species):

Uronema parduzci

Dose descriptor:

EC0

Effect conc.:

93 mg/L

Description of key information

Inhibition of WWTP microorganisms (hexan-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:

62 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.

Among the available existing data there is one reliability 2 study available, for the species Pseudomonas putida. A 16-h toxicity threshold of 62 mg/L was determined. This is supported by consistent data for other micro-organism species. The available data are taken into account in environmental modelling. 

This is supported by results of non-assignable reliability studies with longer chain-lengths within the C6 -24 Alcohols Category, indicating EC₅₀in the hundreds of mg/l (in some cases, up to and exceeding the limit of solubility) for respiration of a mixed microbial culture.

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 6.1 of the ECOTOXICITY Alcohols C6-24 Category report, 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 the environmental fate section) 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).

 

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).

Table: Micro-organism toxicity for species of potential relevance to WWTP systems

CAS	Chemical Name	Comment	Water solubility (mg/L)	Species	Endpoint	Result (mg/L)	Effect	Reliability	Reference
111-27-3	Hexan-1-ol		6320	Pseudomonas putida	16-hr Toxicity Threshold (TT)	62	Cell multiplication (similar to ISO 10712)	2	Bringmann and Kuhn, 1980
111-27-3	Hexan-1-ol		6320	Uronema parduczi	EC0	93	Not stated	4	Verschueren, 1996
111-27-3	Hexan-1-ol		6320	P. putida	30 min EC10	3000	Cell multiplication (DIN 38412 Part 8)	4	Henkel unpublished
111-27-3	Hexan-1-ol		6320	P. putida	16-hr EC10	10,000	Respiration (DIN 38412 Part 27)	4	unreferenced; IUCLID 2000 CD-ROM
111-70-6	Heptan-1-ol	Supporting	1410	P. putida	16-hr Toxicity Threshold (TT)	67	Cell multiplication (similar to ISO 10712)	2	Bringmann and Kuhn, 1980
111-70-6	Heptan-1-ol	Supporting	1410	U. parduczi	EC0	17	Not stated	4	Verschueren, 1996
111-87-5	Octan-1-ol		551	P. putida	16-hr Toxicity Threshold (TT)	>50	Cell multiplication (similar to ISO 10712)	2	Bringmann and Kuhn, 1980
111-87-5	Octan-1-ol		551	Chilomonas paramecium	48 h EC5	>20	Cell multiplication	4	Verschueren, 1996
111-87-5	Octan-1-ol		551	U. parduczi	20 h TGK 5%	23	Cell multiplication	4	Bringmann and Kuhn, 1980
111-87-5	Octan-1-ol		551	Clostridium acetobutylicum(anaerobic)	6-h EC50	130.3	Growth	4	Izardet al., 1989
111-87-5	Octan-1-ol		551	Activated sludge	3 h EC50	350	Respiration (OECD 209)	4	Tanget al., 1990
111-87-5	Octan-1-ol		551	Activated sludge	EC50	325.6	Heat flux	4	Beaubienet al., 1985
111-87-5	Octan-1-ol		551	Activated sludge	24h EC50	200	Respiration (other methodology)	4	Tanget al., 1990
111-87-5	Octan-1-ol		551	P. putida	30 min EC10	10,000	Respiration (DIN 38412 Part 27)	4	Bringmann and Kuhn, 1980 Henkel (undated)
111-87-5	Octan-1-ol		551	Mixed culture	75 min EC50	625	Respiration	4	Vaishnavet al., 1986
112-30-1	Decan-1-ol		39.5	P. putida	30-min. EC0	10,000	Respiration (DIN 38412 Part 27)	2	Henkel, 1999a
112-30-1	Decan-1-ol		39.5	Mixed microbial culture	75 min EC50	443	Respiration	4	Vaishnavet al., 1985
112-30-1	Decan-1-ol		39.5	P. putida	30 min EC0	10,000	Respiration	4	Henkel, unpublished
112-53-8	Dodecan-1-ol		2.07	P. putida	30-min. EC0	>10,000	Respiration (DIN 38412Part27)	1	Henkel, 1994b
80206-82-2	C12-14 Alcohols	Supporting		P. putida	30 min EC0	>10,000	Respiration (DIN 38412Part27)	4	Henkel unpublished
80206-82-2	C12-14 Alcohols	Supporting		P. putida	30 min EC0	10,000	Respiration (DIN 38412Part27)	4	Henkel unpublished
112-72-1	Tetradecan-1-ol		0.191	P. putida	30 min EC50	>10,000	Respiration (DIN 38412Part27)	4	Henkel unpublished
68002-94-8	C16-18 and C18 Unsturated	Supporting		P. putida	30-min. EC10	>10,000	Respiration (DIN 38412Part27)	2	Henkel, 1988a
112-92-5	Octadecan-1-ol		0.0011	P. putida	30-min.EC0	>10,000	Respiration (DIN 38412Part27)	1	Henkel, 1994c

References:

Bringmann, G. and Kuhn, R. 1980. Comparison of the toxicity thresholds of water pollutants to bacteria, algae, protozoa in the cell multiplication inhibition test.Water Research 14:231-241.

Verschueren, K. (ed.). 1996. Handbook of Environmental Data on Organic Chemicals. 3rd ed. New York: John Wiley & Sons, Inc.

Izardet al., 1989:  Appl. Microbiol. Biotechnol. 31, 179-183 (1989).

Tang, N.H.et al., J. Environ.Eng. (New York) 116, 1076-1084 (1990)

Beaubien, A.et al., Water Res. 19, 747-755 (1985)Beilstein On-Line database.

Vaishnav, D.D., Toxicity Assessment 1, 227-240 (1986)

Henkel KGaA.1999a. 1-Decanol: Acute toxicity bacteria. Unpublished results. Biological Research and Product Safety/Ecology. Test Substance Registration No. 7200.

Vaishnav, D.D. and Lopas, D.M. Dev. Industr. Microbiol. 26 (1985), 557-565

Henkel KGaA.1994b. Report-Nummer R 9400236. A. Kirch. Marz 1994.

Henkel KGaA. 1988a.Biological Research and Product Safety/Ecology. Test substance registration No. 6802. Bacterial toxicity.

Henkel KGaA. 1994c.1-Octadecanol: Sauerstoffzehrungshemmtest mit Bakterian. Abschlubericht. Report-Nummer R 9400049. A. Kirch. Januar 1994.

Henkel KGaA, unpublished data (1), Archive-No. 7198 (no further details available); cited in IUCLID 2000 CD-ROM (source documentation not available)

Henkel KGaA, unpublished data (2); cited in IUCLID 2000 CD-ROM (source documentation not available)

Henkel KGaA, unpublished data (3), Final Report 882633 (no further details available); cited in IUCLID 2000 CD-ROM (source documentation not available)

Henkel KGaA, unpublished data (4), Registry No. 6801 (no further details available); cited in IUCLID 2000 CD-ROM (source documentation not available)

Henkel KGaA, unpublished data (5), File 427/1 (no further details available); cited in IUCLID 2000 CD-ROM (source documentation not available)

Henkel KGaA, unpublished data (6), Test No. 9300287 31; Final Report 9500603 (no further details available); cited in IUCLID 2000 CD-ROM (source documentation not available)