2-butyl-2-ethylpropanediol

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:

72 hours, 27 to 30 June 1995

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline and GLP-compliant study.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2-Butyl-2-ethyl-1,3-propanediol

IUPAC Name:

2-Butyl-2-ethyl-1,3-propanediol

Constituent 2

Reference substance name:

2-butyl-2-ethylpropanediol

EC Number:

204-111-7

EC Name:

2-butyl-2-ethylpropanediol

Cas Number:

115-84-4

Molecular formula:

C9H20O2

IUPAC Name:

2-butyl-2-ethylpropane-1,3-diol

Details on test material:

- Name of test material (as cited in study report): BEPD
- Physical state: colourless solid
- Analytical purity: 99.5%
- Lot/batch No.: HRC accession number 20.4.95/1
- Expiration date of the lot/batch: 31 December 1995.
- Storage condition of test material: in darkness at room temperature (ca. 20 degrees C).

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Not applicable

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Samples were taken at 0 hours (fresh media) and 72 hours (expired media).

Test solutions

Vehicle:

no

Details on test solutions:

The test material was dispersed directly in sterile nutrient medium with the aid of unltrasonic disruption for 30 minutes.

Test organisms

Test organisms (species):

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

Details on test organisms:

- Strain number: CCAP 278/4
- Source: Culture Centre of Algae & Protozoa c/o Freshwater Biological Association, Cumbria, UK.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

Not applicable

Test conditions

Test temperature:

23 °C

pH:

7.3 - 8.1

Dissolved oxygen:

Not applicable

Salinity:

Not applicable

Nominal and measured concentrations:

Nominal: 2.2, 4.6, 10, 22, 46 and 100 mg/L
Measured: 2.2, 4.6, 9.8, 21, 45 and 100 mg/L

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

94 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

biomass

Remarks:

(area under the growth curve, EbC50)

Remarks on result:

other: 95% CL: 83 - 106 mg BEPD/L

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Effect concentrations 3

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

45 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

growth rate

Results with reference substance (positive control):

Not applicable

Reported statistics and error estimates:

Williams' test (1971, 1972) was used to compare the percentage inhibition in each treated group with the baseline (control) values. Bartlett's test for homogeneity of variance (1937) was also applied.

Any other information on results incl. tables

Results of the definitive test are compiled below:

Nominal BEPD concentration (mg/L)	Mean BEPD concentration (mg/L)				Mean cell counts (cells x 10000/ml)
	0 hours	72 hours	Mean	Mean as % of nominal	0 hours	24 hours	48 hours	72 hours
Control	ND	ND	-	-	0.99	3.7	12	59
2.2	2.121	2.230	2.2	99	0.99	3.2	12	57
4.6	4.450	4.800	4.6	101	1.0	3.8	31	65
10	9.400	10.10	9.8	98	0.97	3.8	12	59
22	20.08	21.22	21	94	1.0	3.8	13	60
46	43.07	47.09	45	98	0.99	3.6	11	53
100	98.13	103.6	100	101	0.99	3.0	6.2	25

ND: None detected

E: Expired media

Nominal BEPD concentration (mg/L)	Mean measured concentration mg BEPD/L	Area under curve at 72 h	% Inhibition*	Growth rate (0 - 72 h)	% Inhibition*
Control	Control	1018	0	0.057	0
2.2	2.2	981	4	0.056	1
4.6	4.6	1137	<12>	0.058	<2>
10	9.8	1040	<2>	0.057	<1>
22	21	1062	<4>	0.057	0
46	45	936	8	0.055	3
100	100	460	55	0.045	21

* Percentage inhibition values calculated using non-rounded data

< > Increase in algal growth

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The 72-hour ErC50 (growth rate), EbC50 (integrated biomass) for S. capricornutum exposed to BEPD under static conditions were >100 and 94 mg BEPD/L, respectively.

Executive summary:

S. capricornutum was exposed to BEPD at nominal concentrations of 2.2, 4.6, 10, 22, 46 and 100 mg/L in a static 72 -hour toxicity test carried out according to OECD 201 guidelines. The test design included an untreated control comprising untreated algal growth medium only. Concentrations of BEPD were verified analytically at test initiation and termination and measured concentrations were 91 - 98% of nominal. The 72 -hour ErC50 and EbC50 endpoints determined were >100 and 94 mg BEPD/L, respectively. The corresponding 72 -hour NOEC based on inhibition of specific growth rate, determined using Williams' test analysis, was 45 mg BEPD/L.