Proxan-sodium

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

activated sludge nitrification inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

equivalent or similar to guideline

Guideline:

ISO 9509 (Toxicity test for assessing the inhibition of nitrification of activated sludge microorganisms)

Principles of method if other than guideline:

The influence of 28 nitrification inhibitors on denitrification of nitrate in soil was studied by determining the effects of different amounts of each inhibitor on the amounts of nitrate lost and the amounts of nitrite, N2O and N2 produced when soil samples were incubated anaerobically after treatment with nitrate or with nitrate and mannitol.

GLP compliance:

not specified

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

Nitrosomonas sp.

Details on inoculum:

Nitrosomonas
Scientific classification
Domain: Bacteria
Phylum: Proteobacteria
Class: Beta Proteobacteria
Order: Nitrosomonadales
Family: Nitrosomonadaceae
Genus: Nitrosomonas

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Hardness:

NR

Test temperature:

20 to 30°C

pH:

6.0-9.0

Dissolved oxygen:

NR

Salinity:

NR

Nominal and measured concentrations:

10 g g–1 soil ,50 g g–1 soil ,100 g g–1 soil.

Reference substance (positive control):

no

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

50 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of nitrification rate

Remarks on result:

other: Sodium Isopropyl Xanthate (SIPX) is a nitrification inhibitor that has a been observed to inhibit soil denitrification at concentrations around 50 ppm, but only in soils previously amended with mannitol to stimulate denitrifying activity

Details on results:

Sodium Isopropyl Xanthate (SIPX) retarded denitrification when applied at the rate of 50 g g–1 soil to soil that had been amended with mannitol to promote microbial activity.
No inhibition of denitrification was observed when this compound was applied at the rate of 10 g g–1 soil, and enhancement of denitrification was observed when it was applied at the rate of 50 or 100 g g–1 soil.

The influence of 28 nitrification inhibitors on denitrification of nitrate in soil was studied by determining the effects of different amounts of each inhibitor on the amounts of nitrate lost and the amounts of nitrite, N2O and N2 produced when soil samples were incubated anaerobically after treatment with nitrate or with nitrate and mannitol.

The inhibitors used included nitrapyrin (N-Serve), etridiazole (Dwell), potassium azide, 2-amino-4-chloro-6-methylpyrimidine (AM), sulfathiazole (ST), 4-amino-1,2,4-triazole(ATC),2,4-diamino-6-trichloromethyl-s-triazine (CL-1580), potassium ethyl xanthate, guanylthiourea (ASU), 4-nitrobenzotrichloride, 4-mesylbenzotrichloride, sodium thiocarbonate (STC), phenylmercuric acetate (PMA), and dicyandiamide (DCD).Only one of the nitrification inhibitors studied (potassium azide) retarded denitrification when applied at the rate of 10 g g–1 soil, and only two (potassium azide and 2,4-diamino-6-trichloromethyl-s-triazine) inhibited denitrification when applied at the rate of 50 g g–1 soil. The other inhibitors either had no appreciable effect on denitrification, or enhanced denitrification, when applied at the rate of 10 or 50 g g–1 soil, enhancement being most marked with 3-mercapto-1,2,4-triazole. Seven of the inhibitors (potassium azide, sulfathiazole,potassium ethyl xanthate,sodium isopropyl xanthate, 4-nitrobenzotrichloride, sodium thiocarbonate, and phenylmercuric acetate) retarded denitrification when applied at the rate of 50 g g–1 soil to soil that had been amended with mannitol to promote microbial activity.Reports that nitrapyrin (N-Serve) and etridiazole (Dwell) inhibit denitrification when applied at rates as low as 0.5 g g–1 soil could not be confirmed. No inhibition of denitrification was observed when these compounds were applied at the rate of 10 g g–1 soil, and enhancement of denitrification was observed when they were applied at the rate of 50 or 100 g g–1 soil.

Validity criteria fulfilled:

yes

Conclusions:

Sodium Isopropyl Xanthate (SIPX) is a nitrification inhibitor that has been observed to inhibit soil denitrification at EC50= 50 mg/l.

Executive summary:

Sodium Isopropyl Xanthate (SIPX) retarded denitrification when applied at the rate of 50 g g–1 soil to soil that had been amended with mannitol to promote microbial activity. No inhibition of denitrification was observed when this compound was applied at the rate of 10 g g–1 soil, and enhancement of denitrification was observed when it was applied at the rate of 50 or 100 g g–1 soil.

Reference 2

Endpoint:

activated sludge nitrification inhibition testing

Type of information:

other: published data

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Sodium Isopropyl Xanthate (SIPX) readily decomposes to carbon disulphide, especially in the presence of moisture/water. Therefore, the health effects of carbon disulphide (CS2) need to be considered in the assessment of Sodium Isopropyl Xanthate (SIPX).

Qualifier:

no guideline available

Principles of method if other than guideline:

The Microtox test for reduction of luminescence in Photobacterium phosphoreum was used. The test was carried out using the procedure described in the manual of the Beckman 2055 apparatus (1982).

GLP compliance:

no

Analytical monitoring:

not required

Vehicle:

no

Test organisms (species):

Photobacterium phosphoreum

Details on inoculum:

marine bacterium

Test type:

static

Water media type:

saltwater

Limit test:

no

Total exposure duration:

15 min

Hardness:

90 mg CaCO3/L

Test temperature:

20 ± 1 °C

pH:

8.7 ± 0.2

Dissolved oxygen:

Not reported

Salinity:

Not reported

Nominal and measured concentrations:

The test was carried out in sealed flasks to prevent evaporation of CS2.
The medium contained major salts, urea, Ca-glycerophosphate, dextrose and trace elements. The complete composition of the test medium is given in Van Leeuwen and Maas, Environ. Pollution A37: 105-115 (1985).

Details on test conditions:

The test was carried out in sealed flasks to prevent evaporation of CS2.

Reference substance (positive control):

no

Duration:

15 min

Dose descriptor:

EC50

Effect conc.:

341 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: inhibition of bacterial luminescence

Remarks on result:

other: 95% C.I.: 260-448 mg/L

Duration:

15 min

Dose descriptor:

EC50

Effect conc.:

708.6 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Sodium Isopropyl Xanthate (SIPX)

Basis for effect:

other: inhibition of bacterial luminescence

Remarks on result:

other: On a molecular weight scaled basis, the EC50 would be 708.6 mg/l. (341 x 158.2) /76.13 =708.6 mg/l

Details on results:

Sodium Isopropyl Xanthate (SIPX) readily decomposes to carbon disulphide, especially in the presence of moisture/water. Therefore, the health effects of carbon disulphide (CS2) need to be considered in the assessment of Sodium Isopropyl Xanthate (SIPX).
On a molecular weight scaled basis, the EC50 would be 708.6 mg/l. (341 x 158.2) /76.13 =708.6 mg/l

This study reports a 15-min EC50 of 341 mg/L (carbon disulphide (CS2) for the marine bacterium Photobacterium phosphoreum based on the results of a Microtox test.

Validity criteria fulfilled:

yes

Conclusions:

The 15-min EC50 of CS2 for Photobacterium posphoreum luminescence was 341 mg/L.
Sodium Isopropyl Xanthate (SIPX) readily decomposes to carbon disulphide, especially in the presence of moisture/water. Therefore, the health effects of carbon disulphide (CS2) need to be considered in the assessment of Sodium Isopropyl Xanthate (SIPX).
On a molecular weight scaled basis, the EC50 would be 708.6 mg/l. (341 x 158.2) /76.13 =708.6 mg/l

Executive summary:

The 15-min EC50 of CS2 for Photobacterium posphoreum luminescence was 341 mg/L.

Sodium Isopropyl Xanthate (SIPX) readily decomposes to carbon disulphide, especially in the presence of moisture/water. Therefore, the health effects of carbon disulphide (CS2) need to be considered in the assessment of Sodium Isopropyl Xanthate (SIPX).

On a molecular weight scaled basis, the EC50 would be 708.6 mg/l. (341 x 158.2) /76.13 =708.6 mg/l

Reference 3

Endpoint:

activated sludge respiration inhibition testing

Type of information:

other: published data

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Sodium Isopropyl Xanthate (SIPX) readily decomposes to carbon disulphide, especially in the presence of moisture/water. Therefore, the health effects of carbon disulphide (CS2) need to be considered in the assessment of Sodium Isopropyl Xanthate (SIPX).

Qualifier:

according to guideline

Guideline:

other: A-Z test, Deutsches Einheidsverfahren DEV-L 9

Principles of method if other than guideline:

Measurement of oxygen consumption of activated sludge in a closed system to prevent evaporation of CS2.

GLP compliance:

no

Analytical monitoring:

not specified

Vehicle:

no

Test organisms (species):

activated sludge

Details on inoculum:

Mixed bacterial population (activated sludge).

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

24 h

Hardness:

NR

Test temperature:

20 ± 1 °C

pH:

8.7 ± 0.2

Dissolved oxygen:

Not reported

Salinity:

Not reported

Details on test conditions:

not available

Reference substance (positive control):

not required

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

13 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Duration:

24 h

Dose descriptor:

EC10

Effect conc.:

4.6 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

27 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Sodium Isopropyl Xanthate (SIPX)

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Remarks on result:

other: On a molecular weight scaled basis, the EC50 would be 27 mg/l. (13 x 158.2) /76.13 =27 mg/l

Duration:

24 h

Dose descriptor:

EC10

Effect conc.:

9.6 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Sodium Isopropyl Xanthate (SIPX)

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Remarks on result:

other: On a molecular weight scaled basis, the EC10 would be 9.6 mg/l. (4.6x 158.2) /76.13 =9.6 mg/l

Details on results:

Sodium Isopropyl Xanthate (SIPX) readily decomposes to carbon disulphide, especially in the presence of moisture/water. Therefore, the health effects of carbon disulphide (CS2) need to be considered in the assessment of Sodium Isopropyl Xanthate (SIPX)
On a molecular weight scaled basis, the EC50 would be 27 mg/l. (13 x 158.2) /76.13 =27 mg/l
On a molecular weight scaled basis, the EC10 would be 9.6 mg/l. (4.6x 158.2) /76.13 =9.6 mg/l

.

Validity criteria fulfilled:

yes

Conclusions:

The EC50 for inhibition of oxygen consumption in activated sludge by CS2 is 13 mg/L.
Sodium Isopropyl Xanthate (SIPX) readily decomposes to carbon disulphide, especially in the presence of moisture/water. Therefore, the health effects of carbon disulphide (CS2) need to be considered in the assessment of Sodium Isopropyl Xanthate (SIPX).
On a molecular weight scaled basis, the EC50 would be 27 mg/l. (13 x 158.2) /76.13 =27 mg/l
On a molecular weight scaled basis, the EC10 would be 9.6 mg/l. (4.6x 158.2) /76.13 =9.6 mg/l

Executive summary:

The EC50 for inhibition of oxygen consumption in activated sludge by CS2 is 13 mg/L.

Sodium Isopropyl Xanthate (SIPX) readily decomposes to carbon disulphide, especially in the presence of moisture/water. Therefore, the health effects of carbon disulphide (CS2) need to be considered in the assessment of Sodium Isopropyl Xanthate (SIPX).

On a molecular weight scaled basis, the EC50 would be 27 mg/l. (13 x 158.2) /76.13 =27 mg/l

On a molecular weight scaled basis, the EC10 would be 9.6 mg/l. (4.6x 158.2) /76.13 =9.6 mg/l

Reference 4

Endpoint:

activated sludge nitrification inhibition testing

Type of information:

other: published data

Adequacy of study:

weight of evidence

Study period:

1980

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Propan-2-ol (Isopropyl alcohol) is both reagents used in the manufacture, as well as decomposition products of xanthates. Therefore, the health effects of Propan-2-ol (Isopropyl alcohol) need to be considered in the assessment of Sodium Isopropyl Xanthate (SIPX).

Qualifier:

equivalent or similar to guideline

Guideline:

DIN 38412-8 (Pseudomonas Zellvermehrungshemmtest)

Deviations:

not specified

Principles of method if other than guideline:

The concentration of the bacterial suspension is measured turbidimetrically; it is expressed by the extinction of the primary light of the monochromatic radiation at 436 nm for a layer of 10 mm thickness. The concentration at which the inhibitory action of a pollutant starts will be present in that step of a dilution series of the pollutant having an extinction value at the end of the test period that is ≥ 3% below the mean value of extinction for non-toxic dilutions of the test cultures.

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

Before preparing the test cultures neutralize the pollutant solution having a known content in sterile double-distilled water to be tested by using the minimum volume of acid or alkaline solution. The initial concentration of the pollutant solution was not reported.

From this pollutant solution, prepare four parallel dilution series in 300 ml Erlenmeyer flasks, stoppered with cotton-lined plastic caps. Each of the dilutions contains 1 part v/v of polutant solution in 2E0 to 2E14 parts v/v mixture. Prepare the dilution series as follows: the first flask of each series contains 160 ml of pollutant solution at the start. Starting from this flask prepare the subsequent dilution steps at a constant dilution ratio by consistently mixing 80 ml of preliminary pollutant dilution and 80 ml double distilled water. Consequently, each flask contains 80 ml of culture liquid at the start. Make up each flask of the three dilution series to be inoculated to 100 ml by adding 5 ml each of stock solution I, 5 ml of stock solution II and 10 ml each of the prepared bacterial suspension from the preliminary culture having a known adjusted extinction value.

Test organisms (species):

Pseudomonas putida

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

16 h

Hardness:

not reported

Test temperature:

25ºC

pH:

not reported

Dissolved oxygen:

not reported

Salinity:

freshwater

Nominal and measured concentrations:

2E0 to 2E14 parts v/v mixture

Details on test conditions:

Following inoculation, the extinction value of the monochromatic radiation at 436 nm for a 10-mm layer of the bacterial suspension of the test cultures will correspond to the extinction value of the Formazin standard suspension TE/F/436 nm = 10.

Leave both inoculated and non-inoculated dilution series at 25ºC for 16 hours. After termination of the test period measure the extinction of the monochromatic radiation at 436 nm in a 10-mm layer in the inoculated dilution series.

Nutrient medium (for stock and preliminary cultures)
Dissolve in 1000 ml double -distilled water:
1.060 g sodium nitrate, NaNO3
0.600 g dipotassium hydrogen phosphate, K2HPO4, anhydrous
0.300 g potassium dihydrogen phosphate, KH2PO4
0.200 g magnesium sulphate, MgSO4.7 H2O
10.000 g D(+) glucose
18.00 g Difco Bacto agar
0.010 g ferrous sulphate, FeSO4.7 H2O
1.5 ml trace elements solution.

Sterilize the solution in a steam sterilizer for 1.5 hours, after which add 3 ml of vitamin solution.

Trace elements solution (in grams per liter of double-distilled water)
0.055 Al2(SO4)3.18 H2O
0.028 KI
0.028 KBr
0.055 TiO2
0.028 SnCl2.2 H2O
0.028 LiCl
0.389 MnCl2.4 H2O
0.614 H3BO3
0.055 ZnSO4.7 H2O
0.055 CuSO4.5 H2O
0.059 NiSO4.6 H2O
0.055 Co(NO3)2.6 H2O

Vitamin solution
0.2 mg biotin (as D+ biotin)
2.0 mg nicotinic acid
1.0 mg thiamine (as thiamine HCl)
1.0 mg p-aminobenzoic acid
0.5 mg panthothenic acid (as D-panthothenic acid, Na-salt)
5 mg pyridoxamine (as pyridoxamine dihydrochloride)
2.0 mg cyanocobalamin (vitamin B12)
100 ml double distilled water

Fill 6 ml each of the nutrient medium into culture tubes, sterilize the latter in a steam sterilizer by fractionated sterilization (three times) for 30 min. Let solidify in slant position.

Stock solution I
20.000 g D(+) glucose
4.240 g sodium nitrate, NaNO3
2.400 g dipotassium hydrogen phosphate, K2HPO4 anhydrous
1.200 g potassium dihydrogen phosphate, KH2PO4
30 ml trace elements solution.

Dissolve glucose and nutrient salts separately in 500 ml double-distilled water each, sterilize in a steam sterilizer for 30 min and unite solutions when cooled.

Stock solution II
Dissolve:
0.200 g ferrous sulphate, FeSO4.7 H2O
4.000 g magnesium sulphate MgSO4.7 H2O

in 1000 ml sterile double distilled water.

Saline
Dissolve:
0.500 g sodium chloride, NaCl

in 1000 ml double-distilled water. Sterilize solution in a steam sterilizer for 30 min.

Reference substance (positive control):

no

Duration:

16 h

Dose descriptor:

other: Toxicity threshold

Effect conc.:

1 050 mg/L

Nominal / measured:

not specified

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Details on results:

For evalution of the toxicological findings at the end of the test period, the mean value (A) of the extinction is calculated for all test cultures that are free from both toxic influence and stimulation of growth except for those having extinction values outside a standard deviation of <3% and also, the mean value (B) of the extinction for those test cultures having the lowest toxic pollutant concentration within the dilution series.

For mathematical evaluation, (a) (highest non-toxic pollutant concentration) is plotted against (A) and (b) (lowest toxic pollutant concentration) against (B) as coordinates. After having entered (A - 3%), the pollutant concentration at which the inhibitory action (c) begins may be obtained from the regression line between (a;A) and (b;B) if a negative deviation of the mean extinction by a 3% difference against the mean extinction value of all test cultures having a non-toxic and non-stimulating pollutant concentration is used as an indicator of the beginning of inhibitory action.

Validity criteria fulfilled:

not applicable

Conclusions:

A 16h Toxicity threshold concentration of 1050 mg/l has been determined for growth inhibition effects to Pseudomonas putida of the test substance. Propan-2-ol (Isopropyl alcohol) is both reagents used in the manufacture, as well as decomposition products of xanthates. Therefore, the health effects of Propan-2-ol (Isopropyl alcohol) need to be considered in the assessment of Sodium Isopropyl Xanthate (SIPX).

Executive summary:

According to the ECHA Guidance on information requirements and chemical safety assessment, Chapter R.7b: Endpoint specific guidance section R.7.8.17.1 Laboratory data on toxicity on STP microorganisms, results of the cell multiplication inhibition test with P. putida (Bringmann and Kühn 1980) can be used for calculation of the PNECmicro-organisms.

Reference 5

Endpoint:

activated sludge nitrification inhibition testing

Type of information:

other: published data

Adequacy of study:

weight of evidence

Study period:

1980

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Propan-2-ol (Isopropyl alcohol) is both reagents used in the manufacture, as well as decomposition products of xanthates. Therefore, the health effects of Propan-2-ol (Isopropyl alcohol) need to be considered in the assessment of Sodium Isopropyl Xanthate (SIPX).

Qualifier:

no guideline followed

Principles of method if other than guideline:

The saprozoic flagellate protozoon Chilomonas paramaecium served as model organism in a standardized medium. The test period required for determination of the TGK was 48h. An electronic cell counter (Coulter) was used for quantitative determination of the protozoa inoculated and their multiplication within the test cultures.

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: TS was dissolved in sterile ddH2O. Whenever necessary, pH was adjusted to 6.9.

Test organisms (species):

Chilomonas paramaecium

Details on inoculum:

- Laboratory culture: yes
- Method of cultivation: C. paramaecium cultures (20 mL organic mineral medium) were incubated in 300 mL Erlenmeyer flasks, closed with metal caps, at 20 °C with the same medium as the test culture
- Preparation of inoculum for exposure: after 72 or 96 h at 20 °C, the pre-cultures were examined over an inverted microscope
- Pretreatment: none
- Initial biomass concentration: 4 mL of appr. 15000 cell/mL

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

npne

Hardness:

not reported

Test temperature:

20 °C

pH:

6.9

Dissolved oxygen:

not reported

Salinity:

freshwater

Nominal and measured concentrations:

1 part TS solution (concentration not specified) in 2E0 - 2E14 parts mixture (i.e. 1:1, 1:2, 1:4, 1:8... 1:16384) (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flask covered with metal caps
- Type: open
- Material: glass; size: 300 mL; fill volume: 20 mL
- Aeration: shaken
- No. of organisms per vessel: appr. 60000 cell
- No. of vessels per concentration: 2
- No. of vessels per control: 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: double distilled water
- Medium (20 mL) prepared with 8 mL Stammlösung 1 + 8 mL TS + 4 mL C. paramecium culture

Stammlösung 1
8 g glycine
290 mg Ca(NO3)2*4(H2O)
70 mg Mg(NO3)2*7(H2O)
40 mg KNO3
26 mg K2HPO4
dissolved in 1 L ddH2O, pH 6.9. To the sterile Stammlösung 1 were then added 7.5 mL pasteurized Stammlösung 2.

Stammlösung 2
0.2 mg D-biotine
2.0 mg nicotinic acid
1.0 mg thiamin HCl
1.0 mg p-aminobenzoic acid
0.5 mg sodium D-pantothenate
5 mg pyridoxamine dihydrochloride
2.0 mg cyanocobalamine
dissolved in 100 mL ddH2O. Pasteurized 30 min at 60 °C

- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Adjustment of pH: none

EFFECT PARAMETERS MEASURED: cell number (Coulter counter)

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

other: Toxicity Threshold Concentration

Effect conc.:

104 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Details on results:

A 48h Toxicity threshold concentration of 104 mg/l has been determined for growth inhibition effects to Chilomonas paramaecium of the test substance.

Validity criteria fulfilled:

not applicable

Remarks:

Dilution series long enough (15 concentrations) to determine a dose effect relationship

Conclusions:

A 48h Toxicity threshold concentration of 104 mg/l has been determined for growth inhibition effects to Chilomonas paramaecium of the test substance.
Propan-2-ol (Isopropyl alcohol) is both reagents used in the manufacture, as well as decomposition products of xanthates. Therefore, the health effects of Propan-2-ol (Isopropyl alcohol) need to be considered in the assessment of Sodium Isopropyl Xanthate (SIPX).

Executive summary:

A 48h Toxicity threshold concentration of 104 mg/l has been determined for growth inhibition effects to Chilomonas paramaecium of the test substance. Propan-2-ol (Isopropyl alcohol) is both reagents used in the manufacture, as well as decomposition products of xanthates. Therefore, the health effects of Propan-2-ol (Isopropyl alcohol) need to be considered in the assessment of Sodium Isopropyl Xanthate (SIPX).

Description of key information

Sodium Isopropyl Xanthate (SIPX) is a nitrification inhibitor that has been observed to inhibit soil denitrification at EC50= 50 mg/l.

Key value for chemical safety assessment

EC50 for microorganisms:

50 mg/L

EC10 or NOEC for microorganisms:

10 mg/L

Additional information

Sodium Isopropyl Xanthate (SIPX) is a nitrification inhibitor that has been observed to inhibit soil denitrification at EC50= 50 mg/l.