Oct-1-ene-3-ol

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was conducted between 14 August 2017 and 17 August 2017 (biological phase).

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Deviations:

yes

Remarks:

Deviating from the study plan the pH in the test medium exceeded the required upper limit (pH = 9) by 0.6 pH units. This deviation has no influence on the integrity of the study results, since all cell growth related validity criteria were fulfilled.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Oct-1-ene-3-ol

EC Number:

222-226-0

EC Name:

Oct-1-ene-3-ol

Cas Number:

3391-86-4

Molecular formula:

C8H16O

IUPAC Name:

oct-1-en-3-ol

Test material form:

liquid

Specific details on test material used for the study:

Batch No.: VE00440179
Colour and Appearance: colourless to pale yellow liquid
Purity: 99.6%

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Samples from the test solutions were analysed to determine actual levels of the test item at start of exposure period (time 0 hours) and following 72 hours of exposure. At time 0 hours the measured concentrations range between 64–91% and decrease after 72 hours exposure at between 0 (Since all concentration levels were measured, the biological results are additionally calculated and reported based on geometric mean measured concentrations at each concentration level. Details are reported in the analytical phase report and in section 18.3 of the study report.

Test organisms

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

The test system used in this study was the freshwater algae Pseudokirchneriella subcapitata (SAG 61.81).
The organisms were originally supplied by Sammlung von Algenkulturen, Albrecht-von-Haller-Institut, Universität Göttingen, Germany.

Study design

Test type:

static

Water media type:

other: OECD medium (modified) + additional NaHCO3

Limit test:

no

Total exposure duration:

72 h

Test conditions

Test temperature:

22.8 to 23.3 °C

pH:

8.3

Nominal and measured concentrations:

Test Concentrations (nominal): 0.237, 0.750, 2.37, 7.50, 23.7 and 75.0 mg test item/L and a control.
Measured: 0.057, 0.174, 0.505, 2.73, 6.27 and 28.5 mg test item/L

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

1.51 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% confidence limit 0.902 - 2.09 mg/L

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

2.56 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% confidence limit 1.79 - 3.27 mg/L

Effect concentrations 3

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

7.05 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% confidence limit 5.83 - 8.71 mg/L

Effect concentrations 4

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.505 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 5

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

0.174 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

Biological endpoints based on both nominal and mean measured concentrations are presented in the study report and dsummarised below in the section "any other information on results incl tables". However, because the test item concentration based on nominal concentration was not stable within ±20% throughout the exposure period, the biological endpoints based on the geometric mean measured concentrations are considered the most appropriate and reported in the effect concentrations table above.
Effects based on yield were also reported (see attached full study report). However, the preferred observational endpoint in the algal inhibition study is growth rate because it is not dependent on the test design (ECHA guidance Chapter R.7b v 2.0, OECD 201 Guidelines). The guideline includes the additional response variable of yield, to satisfy current regulatory requirements in some countries. The EU CLP regulation (No 1272/2008 and its adaption 286/2011) also states that classification should be based on the ErC50. Thus only the effects based on growth rate are presented in the above "effects concentration" table. Furthermore, the preferred observational endpoint in long-term studies is the EC10 value because it is derived from the dose response curve. In contrast the NOEC strongly depends on the experiment design (e.g. the concentrations used in the test). Thus the 72-h EC50 and EC10 based on growth rate are used for classification purposes, which were determined in this study to be 7.05 mg/L and 1.51 mg/L respectively.

Any other information on results incl. tables

Analytical findings

Samples from the test solutions were analysed to determine actual levels of the test item at start of exposure period (time 0 hours) and following 72 hours of exposure. At time 0 hours the measured concentrations range between 64–91% and decrease after 72 hours exposure at between 0 (<LOD) and 18% of the nominal concentrations. Therefore, the test item concentration based on nominal concentration was not stable within ±20% throughout the exposure period.

Since all concentration levels were measured, the biological results are additionally calculated and reported based on geometric mean measured concentrations at each concentration level. Details are reported in the analytical phase report and in section 18.3.

Biological findings

A clear concentration-response relationship was observed for both biological parameters growth rate and yield during the exposure period. The resulting endpoints are presented in Table 10 and Table 11, respectively, based on geometric mean measured concentrations and based on nominal concentrations expressed in mg/L.

The following ECx, NOEC and LOEC values for the parameters cell number and biomass expressed in yield and growth rate, based on statistical evaluation of biological results and measured geometric mean concentrations of the test item (Amyl Vinyl Carbinol).

Summary of biological results based on measured test item concentrations in mg Amyl Vinyl Carbinol/L.

      Endpoints [mg Amyl Vinyl Carbinol/L]

Parameter       EC10                  EC20                  EC50           NOEC            LOEC

Yield              0.546                  0.991                  2.44              0.505              0.174

(95% cI)       (0.336–0.755)    (0.708–1.25)       (2.11–2.75)

Growth Rate 1.51                     2.56                     7.05             0.505              0.174

(95% cI)       (0.902–2.09)       (1.79–3.27)          (5.83–8.71)              

cl = confidence limit

NOEC, LOEC and ECx values for the parameters cell number and biomass expressed in yield and growth rate are based on statistical evaluation of biological results and nominal concentrations in mg test item/L were given in the following table.

Summary of biological results based on nominal concentrations in mg test item/L.

      Endpoints [mg test item/L]

Parameter       EC10                  EC20                   EC50           NOEC            LOEC

Yield              1.66                    3.02                     7.47              0.750              2.37

(95% cI)       (1.42–1.89)          (2.71–3.31)         (7.06–7.89)                     

Growth Rate 5.27                     8.72                     22.8              0.750              2.37

(95% cI)       (4.14–6.38)         (7.31–10.1)          (20.6–25.3)                            

cl = confidence limit

Validity of the test:

All validity criteria were fulfilled as required by the study plan:

 

Required:	Found:
Mean biomass increase in the control cultures:factor of at least 16 within the 72-hour test period	237
Mean coefficient of variation for section-by-section specific growth rates in the control cultures:up to 35%	17.4%
Coefficient of variation of average specific growth rates during test period in replicate control cultures:up to 7%	1.4%

 

The study is therefore considered to be valid.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The 72-h EC50 and EC10 based on growth rate are used for classification purposes, which were determined in this study to be 7.05 mg/L and 1.51 mg/L respectively based on geometric mean measured concentrations.

Executive summary:

The impact of the test item Amyl Vinyl Carbinol on the growth of the freshwater green algal species Pseudokirchneriella subcapitata was investigated in a 72-hour static test according to the OECD Guideline for the Testing of Chemicals, No. 201 (2011). Based on measured concentrations, the 72h EC50 of Pseudokirchneriella subcapitata was found to be 7.05 mg/L. The corresponding 72 ErC10 is 1.51 mg/L.