Propiononitrile

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:

30-1-2013/1-2-2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

yes

Remarks:

The Certificate of Analysis was not accompanied by a GLP compliance statement. Stability information was not provided to the testing facility.

Test material

Test material information

Constituent 1

Reference substance name:

Propiononitrile

EC Number:

203-464-4

EC Name:

Propiononitrile

Cas Number:

107-12-0

Molecular formula:

C3H5N

IUPAC Name:

propanenitrile

Test material form:

liquid

Specific details on test material used for the study:

Label Identification: Propionitrile
Date and Quantity Received: 17 Dec 12; 302.8 g GW
Physical Description: Clear liquid
Storage Conditions: Room temperature
Purity & Composition: 98 %
Information Stability: Not provided to testing facility
Lot: #34
sample size:500 ml

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Sampling at 0 and 72h hours exposure

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Concentrations were prepared by weighing test material on a calibrated scale (mg) then mixing with OECD medium.
- Controls: sterile medium and zinc chloride

Test organisms

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Source (laboratory, culture collection): STILLMEADOW, Inc. cultures
- Age of inoculum (at test initiation): Mass culture initiated 3-7 ± 1 days prior to dosing
- Method of cultivation: Environmentally controlled room, with test chambers of 250-mL sterile Erlenmeyer flasks in a light and temperature controlled cabinet held within an environmental chamber. Tests containers were maintained on a shaking table set a ~ 100 cycles/minute. OECD medium was used.

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

Hardness:

255 ppm

Test temperature:

26°C

pH:

Initial pH was 8.1 for the control and 7.3 for 100 mg/L.

Dissolved oxygen:

Test containers were maintained on a shaking table set at ~100 cycles/minute

Salinity:

no data

Conductivity:

50 µmhos/cm

Nominal and measured concentrations:

See " any other information on results" for more details.

Sample Time 0h Nominal (mg/L) 6.25, 12.5, 25, 50, 100 - Verification (mg/L) 4.9, 6.73, 18.3, 36.7, 79.4
Sample Time 72 Hr Nominal (mg/L) 6.25, 12.5, 25, 50, 100 - Verification (mg/L) <1, <1, 2.41, 3.8, 9.97

Geometric means of the dosing concentrations determined due to loss over the exposure period. Geometric mean concentrations determined at: 1.7, 2.3, 6.6, 11.8 and 28.1 mg/L. The lowest two concentrations, were calculated based on the 72 hour predicted value (based on the average loss seen in the higher concentrations).

Details on test conditions:

TEST SYSTEM
- Test vessel: 250-mL sterile Erlenmeyer flasks in a light and temperature controlled cabinet held within an environmental chamber
- Aeration: Test containers were maintained on a shaking table set at ~100 cycles/minute
- Initial cells density: 50,000 cells/mL
- Control end cells density: 108 x 10(4) cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes


OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Light intensity and quality: 3680-3980 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : cell density with hemocytometer at 24, 48 and 72 hours


TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Range finding study: yes
- Test concentrations RF: 1, 5, 10, 50, and 100 mg/L
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

yes

Remarks:

three flasks treated with 10 mg/L zinc chloride

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

IC50

Effect conc.:

< 1.7 mg/L

Nominal / measured:

meas. (geom. mean)

Basis for effect:

cell number

Effect concentrations 2

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

< 1.7 mg/L

Nominal / measured:

meas. (geom. mean)

Basis for effect:

cell number

Effect concentrations 3

Duration:

72 h

Dose descriptor:

IC50

Effect conc.:

2.005 mg/L

Nominal / measured:

meas. (geom. mean)

Basis for effect:

growth rate

Effect concentrations 4

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

< 1.7 mg/L

Nominal / measured:

meas. (geom. mean)

Basis for effect:

growth rate

Effect concentrations 5

Key result

Duration:

72 h

Dose descriptor:

IC50

Effect conc.:

< 1.7 mg/L

Nominal / measured:

meas. (geom. mean)

Basis for effect:

growth rate

Remarks:

growth curve area

Effect concentrations 6

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

< 1.7 mg/L

Nominal / measured:

meas. (geom. mean)

Basis for effect:

growth rate

Remarks:

growth curve area

Details on results:

See attached picture for details of the results

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Other: 0 cell density at 72h

Reported statistics and error estimates:

95% confidence interval

Any other information on results incl. tables

Table 1. Dose verification results

Sample time	Nominal (mg/l)	Verification (mg/l)
0 Hr	Control	0
	6.25	4.9
	12.5	6.73
	25	18.3
	50	36.7
	100	79.4
72 Hr	Control	0
	6.25	<1
	12.5	<1
	25	2.41
	50	3.8
	100	9.97

Table 1. Daily cell counts and terminal pH

Concentration mg/L (Dose Verified mg/L)	Replicate	Cell Density x 104 cells/mL			Terminal pH
		24 Hours	48 Hours	72 Hours
Control	A	16	30	108^a, b	7.5
	B	20	36	123^a, b	7.4
	C	10	21	101^a, b	7.5
	D	11	21	96^a, b	7.4
	E	13	27	105^a, b	7.4
	F	10	22	98^a, b	7.4
6.25 (1.7)	A	5	9	25^a, c	7.4
	B	7	10	38^a, c	7.4
	C	6	11	31^a, c	7.4
12.5 (2.3)	A	8	15	18^a, d	7.2
	B	5	11	16^a, d	7.2
	C	6	14	15^a, d	7.3
25 (6.6)	A	5	7	14^a, d	7.3
	B	8	12	20^a, d	7.3
	C	5	6	21^a, d	7.3
50 (11.8)	A	5	9	8^a, e	7.1
	B	9	9	10^a, e	7.2
	C	4	8	6^a, e	7.2
100 (28.1)	A	0	4	2^a, e	7.7
	B	2	2	1^a, e	7.7
	C	3	3	3^a, e	7.7
C2 10 mg/L ZnCl2	A	2	2	0	7.5
	B	3	3	0	7.5
	C	1	0	0	7.6

 

Initial pH was 8.1 for the control and 7.3 for 100 mg/L.  a- cells appear healthy, b- green solution, c- light green solution; d- clear solution with hint of green; e- clear solution

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The acute toxicity of the test substance on growth inhibition and phytotoxicity to the freshwater algae Pseudokirchneriella subcapitata in a 72-hr static test, resulted in an IC50 for cell density, growth rate area and growth rate of <1.7, <1.7 and 2.005 mg/L respectively, based on the geometric means of the measured concentrations. The NOECs for cell density, growth rate area and growth rate was <1.7 mg/L for all endpoints.

Executive summary:

The acute toxicity of Propionitrile to freshwater algae Pseudokirchneriella subcapitata was assessed using the methods OECD 201 standard test. The study is reliable (Klimisch 1) and with GLP certification. The exposure concentrations were measured at time 0 and time 72 hours and were found to have decreased greatly; due to the this exposure concentrations were based on the geometric mean of the time 0 and time 72 hour concentrations.

The IC50 for cell density, growth rate area and growth rate were calculated at <1.7, <1.7 and 2.005 mg/L respectively, based on the geometric means of the measured concentrations. The NOECs for cell density, growth rate area and growth rate were <1.7 mg/L for all endpoints.