Trisodium 8-hydroxypyrene-1,3,6-trisulphonate

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to microorganisms, other

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data for the target chemical is summarized based on the structurally similar read across chemicals

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

other: as mentioned below

Principles of method if other than guideline:

WoE report is based on two toxicity study of micro-organisms for the test chemical :
1. toxicity to micro-organisms tests was carried out .
2. The Microtox acute toxicity assay was performed by using a modified strain of Vibrio fischeri

GLP compliance:

not specified

Analytical monitoring:

not specified

Details on sampling:

2. Sample storage conditions before analysis: Frozen samples were brought to room temperature, and centrifuged.

Vehicle:

not specified

Test organisms (species):

Vibrio fisheri

Details on inoculum:

2. Details on test organisms
Laboratory culture: From eight serial dilutions, the percent concentration to decrease 20% of the luminescence of amodified strain of Vibrio fischeri
(EC20) after 5 min incubation was calculated with the Microtox data analysis program
Method of cultivation: No data
Preparation of inoculum for exposure: Frozen samples were brought to room temperature, and centrifuged. The pH of the samples was adjusted where necessary to 6 by adding 0.5 ml 0.58 M KH2 PO4 and 70 μl 1 M NaOH. Colour correction was done at 490 nm.
Pretreatment: No data
Initial biomass concentration: No data

Test type:

static

Water media type:

freshwater

Total exposure duration:

5 min

pH:

2. The pH of the samples was adjusted where necessary to 6 by adding 0.5 ml 0.58 M KH2 PO4 and 70 μl 1 M NaOH

Details on test conditions:

2. TEST SYSTEM
Test vessel: Microtox 500 Analyzer
No. of vessels per concentration (replicates): triplicate analysis.

OTHER TEST CONDITIONS
Adjustment of pH: The pH of the samples was adjusted where necessary to 6 by adding 0.5 ml 0.58 M KH2 PO4 and 70 μl 1 M NaOH
Photoperiod:
Light intensity: Colour correction was done at 490 nm.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : The percent concentration to decrease 20% of the luminescence of amodified strain of Vibrio fischeri (EC20) after 5 min incubation was calculated with the Microtox data analysis program [Microtox Omni Software
(1999) Azur Environmental, Newark, Del.].

Duration:

5 min

Dose descriptor:

EC50

Effect conc.:

22.1 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

other: inhibition of light output

Remarks on result:

other: EC50: 22.19+/-2.47

Duration:

5 min

Dose descriptor:

other: EC20

Effect conc.:

44.6 other: % dilution

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Remarks on result:

other: EC20 is the percent dilution of the sample (v/v) to cause 20% decrease of bioluminescence in the Microtox assay

Details on results:

2. EC50 refers to the concentration of compound (mg/L) required to inhibit the light output of V. fischeri by 50% after a 5 min exposure period.

Results with reference substance (positive control):

2. Result with reference substance (positive control)
Results with reference substance valid?: Yes
Other: Glucose was used as negative control and it was non- toxic

2. Table 1 : Toxicity of the components in the Microtox assay

 

Sample	EC20 (% DILUTION)
Positive control [ZnSO4.7H20]	0.72±0.1
Distilled water	>100
100mg/l Amaranth	44.6±11.6
1g/l Glucose	>100

 

EC20 is the % dilution of the sample (v/v) to cause 20% decrease of bioluminescence in the Microtox assay

>100% indicates no toxic effect

Validity criteria fulfilled:

yes

Conclusions:

Toxicity value of test material to Vibrio fisheri was found to be EC50: 22.19 and EC20 44.6 on the basis of growth inhibition after a 5 min exposure period.

Executive summary:

Data available for the structurally and functionally similar read across chemicals has been reviewed to determine the toxicity of micro-organisms of the test chemical test material.The studies are as mentioned below:

1. Toxicity value of test chemical to Vibrio fisheri was found to be EC50: 22.19+/-2.47 on the basis of inhibition of the light output after a 5 min exposure period.

2. The Microtox acute toxicity assay was performed by using a modified strain ofVibrio fischeri

Frozen samples were brought to room temperature, and centrifuged. The pH of the samples was adjusted where necessary to 6 by adding 0.5 ml 0.58 M KH2 PO4 and 70μl 1 M NaOH. Colour correction was done at 490 nm. The Microtox acute toxicity assay was performed in a Microtox 500 Analyzer on samples before and after decoloration according to the test protocols defined by the manufacturer From eight serial dilutions, the percent concentration to decrease 20% of the luminescence of amodified strain ofVibrio fischeri(EC20)after 5 min incubation was calculated with the Microtox data analysis program [Microtox Omni Software(1999) Azur Environmental, Newark, Del.]. A solution of 1 g/l ZnSO4·7H2O was used as the positive control and 1 g/l glucose as the negative control. Each EC20 reported is the average of triplicate analysis.

The concentration to decrease 50% of the bacterial luminescence in the Microtox acute assay (EC50) is normally reported. However, in most of these studies, the EC50 before or after decoloration was greater than 100% indicating that there was no toxicity or toxicity change. To better evaluate whether the decoloration process affected toxicity, the dilution required to decrease 20% of the bacterial luminescence relative to the control (EC20)was reported instead. The following rating was adapted from Coleman & Qureshi (1985) –

EC20:>100%=nontoxic;

>75–100%=slightly non-toxic;

 >50–75%=toxic;

>25–50%=moderately toxic;

<25% very toxic.

The toxicity of 100mg/l of test material determined in terms of EC20 (% dilution) was 44.6±11.6.

According to the ranking scheme for Microtox assay using EC20 values, test material can be categorized under moderately toxic category.

Thus based on the above summarised studies, test material and it’s structurally and functionally similar read across substance, it can be concluded that test material is not likely to be toxic to the micro-organisms.

Description of key information

Toxicity to microorganisms:

Data available for the structurally and functionally similar read across chemicals has been reviewed to determine the toxicity of micro-organisms of the test chemical test material.The studies are as mentioned below:

1. Toxicity value of test chemical to Vibrio fisheri was found to be EC50: 22.19+/-2.47 on the basis of inhibition of the light output after a 5 min exposure period.

2. The Microtox acute toxicity assay was performed by using a modified strain ofVibrio fischeri

Frozen samples were brought to room temperature, and centrifuged. The pH of the samples was adjusted where necessary to 6 by adding 0.5 ml 0.58 M KH2 PO4 and 70μl 1 M NaOH. Colour correction was done at 490 nm. The Microtox acute toxicity assay was performed in a Microtox 500 Analyzer on samples before and after decoloration according to the test protocols defined by the manufacturer From eight serial dilutions, the percent concentration to decrease 20% of the luminescence of amodified strain ofVibrio fischeri(EC20)after 5 min incubation was calculated with the Microtox data analysis program [Microtox Omni Software(1999) Azur Environmental, Newark, Del.]. A solution of 1 g/l ZnSO4·7H2O was used as the positive control and 1 g/l glucose as the negative control. Each EC20 reported is the average of triplicate analysis.

The concentration to decrease 50% of the bacterial luminescence in the Microtox acute assay (EC50) is normally reported. However, in most of these studies, the EC50 before or after decoloration was greater than 100% indicating that there was no toxicity or toxicity change. To better evaluate whether the decoloration process affected toxicity, the dilution required to decrease 20% of the bacterial luminescence relative to the control (EC20)was reported instead. The following rating was adapted from Coleman & Qureshi (1985) –

EC20:>100%=nontoxic;

>75–100%=slightly non-toxic;

 >50–75%=toxic;

>25–50%=moderately toxic;

<25% very toxic.

The toxicity of 100mg/l of test material determined in terms of EC20 (% dilution) was 44.6±11.6.

According to the ranking scheme for Microtox assay using EC20 values, test material can be categorized under moderately toxic category.

Thus based on the above summarised studies, test material and it’s structurally and functionally similar read across substance, it can be concluded that test material is not likely to be toxic to the micro-organisms.

Key value for chemical safety assessment

EC50 for microorganisms:

22 mg/L

Additional information

Toxicity to microorganisms:

Data available for the structurally and functionally similar read across chemicals has been reviewed to determine the toxicity of micro-organisms of the test chemical test material.The studies are as mentioned below:

1. Toxicity value of test chemical to Vibrio fisheri was found to be EC50: 22.19+/-2.47 on the basis of inhibition of the light output after a 5 min exposure period.

2. The Microtox acute toxicity assay was performed by using a modified strain ofVibrio fischeri

Frozen samples were brought to room temperature, and centrifuged. The pH of the samples was adjusted where necessary to 6 by adding 0.5 ml 0.58 M KH2 PO4 and 70μl 1 M NaOH. Colour correction was done at 490 nm. The Microtox acute toxicity assay was performed in a Microtox 500 Analyzer on samples before and after decoloration according to the test protocols defined by the manufacturer From eight serial dilutions, the percent concentration to decrease 20% of the luminescence of amodified strain ofVibrio fischeri(EC20)after 5 min incubation was calculated with the Microtox data analysis program [Microtox Omni Software(1999) Azur Environmental, Newark, Del.]. A solution of 1 g/l ZnSO4·7H2O was used as the positive control and 1 g/l glucose as the negative control. Each EC20 reported is the average of triplicate analysis.

The concentration to decrease 50% of the bacterial luminescence in the Microtox acute assay (EC50) is normally reported. However, in most of these studies, the EC50 before or after decoloration was greater than 100% indicating that there was no toxicity or toxicity change. To better evaluate whether the decoloration process affected toxicity, the dilution required to decrease 20% of the bacterial luminescence relative to the control (EC20)was reported instead. The following rating was adapted from Coleman & Qureshi (1985) –

EC20:>100%=nontoxic;

>75–100%=slightly non-toxic;

 >50–75%=toxic;

>25–50%=moderately toxic;

<25% very toxicy

The toxicity of 100mg/l of test material determined in terms of EC20 (% dilution) was 44.6±11.6.

According to the ranking scheme for Microtox assay using EC20 values, test material can be categorized under moderately toxic category.

Thus based on the above summarised studies, test material and it’s structurally and functionally similar read across substance, it can be concluded that test material is not likely to be toxic to the micro-organisms.