Potassium salicylate

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Experimental test result using OECD guideline.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2014

Report date:

2014

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Principles of method if other than guideline:

This study was designed to assess the effect of the substance Sodium salicylate (CAS No. 54-21-7) on the growth of green alga Chlorella vulgaris. The study was conducted in accordance with “OECD guideline for testing of chemicals No. 201 – Alga growth inhibition test”.

GLP compliance:

no

Remarks:

Test conducted originally for other purposes than REACH and thus conducted as per the OECD guidelines only.

Test material

Test material information

Constituent 1

Reference substance name:

Sodium salicylate

EC Number:

200-198-0

EC Name:

Sodium salicylate

Cas Number:

54-21-7

Molecular formula:

C7H6O3.Na

IUPAC Name:

sodium salicylate

Test material form:

solid

Details on test material:

- Name of test material (as cited in study report):sodium salicylate- Molecular formula :C7H6O3.Na- Molecular weight : 160.1035 g/mol- Substance type: organic- Physical state: solid- Smilies notation: c1(c(cccc1)O)C(=O)[O-].[Na+]- InChI: 1S/C7H6O3.Na/c8-6-4-2-1-3-5(6)7(9)10;/h1-4,8H,(H,9,10);/q;+1/p-1

Specific details on test material used for the study:

- Name of test material (as cited in study report):sodium salicylate- Molecular formula :C7H6O3.Na- Molecular weight : 160.1035 g/mol- Substance type: organic- Physical state: solid- Smilies notation: c1(c(cccc1)O)C(=O)[O-].[Na+]- Inchi: 1S/C7H6O3.Na/c8-6-4-2-1-3-5(6)7(9)10;/h1-4,8H,(H,9,10);/q;+1/p-1

Sampling and analysis

Analytical monitoring:

not specified

Details on sampling:

Storage ConditionsStore in cool place. Keep container tightly closed in a dry and well-ventilated place. Substance is Hygroscopic.

Test solutions

Vehicle:

yes

Details on test solutions:

The test Sodium salicylate was prepared by adding 60 mg of test substance in 300 ml of BBM to get the final concentration of 200 mg/L. The remaining test solutions were prepared by dilution from the above stock solution. To have a better growth and visibility of cells, the initial cell density of the culture was kept 1 X 104 cells/ml. Care was taken to have a homogeneous solution for the experiment.

Test organisms

Test organisms (species):

Chlorella vulgaris

Details on test organisms:

The fresh water green alga Chlorella vulgaris, was used as the test organism. Sterile, unicellular, liquid cultures of algae.The culture was examined under the microscope to confirm that it was unicellular, healthy and not contaminated. The medium to be used for the growth of algae was Bold’s Basal Medium (BBM). It is a medium composed of macronutrients, micronutrients, alkaline EDTA solution and Iron solution. Stock solution of each of these was prepared separately and then a complete medium was prepared and sterilized. De-ionized water was used to prepare the BBM.

Study design

Test type:

static

Water media type:

freshwater

Total exposure duration:

72 h

Test conditions

Test temperature:

24 °C ±2°C.

pH:

6.7 to 7.4

Nominal and measured concentrations:

6.25 mg/l, 12.5 mg/l, 25 mg/l, 50 mg/l, 100 mg/l and 200mg/l

Details on test conditions:

Light QualityWhite Fluoroscent LightLight Intensity1500LuxPhotoperiod16 Hour Light Period :6 Hour Dark PeriodRPM Speed120 Revolutions per minuteWater Deionized WaerTest vessel size100mlTest solution volume60mlDilution waterBold’s Basal MediumTest concentration Six test concentration were: Replicates per concentrationThree replicates for ControlTwo replicates for each test concentration

Results and discussion

Effect concentrations

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

48.29 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: calculated from equation through probit analysis

Details on results:

The microscopic observations were also noted in each of the experimental flasks. All the cells appeared healthy, round and green throughout the test duration in the control and in the experimental flask also no significant changes were observed.

Any other information on results incl. tables

Table 1: Showing the average cell count using Haemocytometer of the experimental flasks at an equal interval of 24hrs, 48hrs and 72hrs

Experimental Flasks and testconcentration	24Hours	48Hours	72Hours
Control
Replicate 1	39 x 10^4	41.5 x 10^4	47 x 10^4
Replicate 2	28 x 10^4	46.5 x 10^4	34 x 10^4
Replicate 3	34 x 10^4	42.5 x 10^4	44 x 10^4
CAS No. 54-21-7
6.25 mg/l
Replicate 1	29.5 x 10^4	24 x 10^4	10.5 x 10^4
Replicate 2	27.5 x 10^4	26.5 x 10^4	12.5 x 10^4
12.5 mg/l
Replicate 1	27 x 10^4	17 x 10^4	19.5 x 10^4
Replicate 2	27.5 x 10^4	20.5 x 10^4	12 x 10^4
25 mg/l
Replicate 1	10.5 x 10^4	16 x 10^4	14.5 x 10^4
Replicate 2	12.5 x 10^4	18.5 x 10^4	15.5 x 10^4
50 mg/l
Replicate 1	28.5 x 10^4	11.5 x 10^4	5.5 x 10^4
Replicate 2	22 x 10^4	12.5 x 10^4	10 x 10^4
100 mg/l
Replicate 1	22.5 x 10^4	3.5 x 10^4	6 x 10^4
Replicate 2	35 x 10^4	6 x 10^4	3.5 x 10^4
200 mg/l
Replicate 1	20 x 10^4	22 x 10^4	2.5 x 10^4
Replicate 2	24.5 x 10^4	22 x 10^4	7 x 10^4

Table 2 : Showing the values of average specific growth rate and percentage inhibition after an interval of 72 hours

	CONTROL		6.25 mg/l		12.5 mg/l		25 mg/l		50 mg/l		100 mg/l		200 mg/l
Average Specific Growth rate (µ)	R1	1.283	R1	0.783	R1	0.990	R1	0.891	R1	0.568	R1	0.597	R1	0.305
	R2	1.175	R2	0.841	R2	0.828	R2	0.913	R2	0.767	R2	0.417	R2	0.648
	R3	1.261
Mean of Avg. Specific growth rate	1.240		0.812		0.909		0.902		0.667		0.507		0.477
Percentage Inhibition (%I)	_		34.451		26.680		27.222		46.141		59.081		61.531

Table 3 : Depicting pH values at test initiation (0 Hours) and test termination ( 72 Hours)

Experimental Flasks and test concentration	0 Hours	72 Hours
CONTROL
Replicate 1	7.3	7.4
Replicate 2	7.2	7.3
Replicate 3	7.4	7.5
CAS No. 54-21-7
6.25 mg/l
Replicate 1	7.2	7.2
Replicate 2	7.1	7.2
12.5 mg/l
Replicate 1	7.3	7.2
Replicate 2	7.0	7.2
25 mg/l
Replicate 1	7.3	7.4
Replicate 2	7.4	7.3
50 mg/l
Replicate 1	7.2	7.2
Replicate 2	7.1	7.1
100 mg/l
Replicate 1	7.0	7.1
Replicate 2	7.1	7.2
200 mg/l
Replicate 1	7.2	7.1
Replicate 2	7.1	7.1

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

After 72 hours of exposure to Sodium salicylate (CAS No. 54-21-7) to various nominal test concentration, EC50 calculated from probit analysis was observed to be 48.29 mg/L and EC50 graphically was observed to be 63.10 mg/L.

Executive summary:

This study was designed to assess the effect of the substance Sodium salicylate (CAS No. 54-21-7) on the growth of green algaChlorella vulgaris. The study was conducted in accordance with “OECD guideline for testing of chemicals No. 201 – Alga growth inhibition test”.

The effect of test substance Sodium salicylate (CAS No. 54-21-7) was studied on the growth of fresh water green algaChlorella vulgaris.The study was conducted following OECD guideline 201- Alga growth inhibition test. The test concentration chosen for the study were 6.25 mg/l, 12.5 mg/l, 25 mg/l, 50 mg/l, 100 mg/l and 200 mg/l were prepared using stock solution of the test substance using de-ionized water. The green alga was exposed to the test concentration for a period of 72 hours to observe average specific growth rate and % growth inhibition under the effect of test substance. EC50 calculated from probit analysis was observed to be 48.29 mg/L and EC50 graphically was observed to be 63.10 mg/L.