Dipotassium oxide

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

other: Published data

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

Principles of method if other than guideline:

Potassium was added a geometric series of concentrations for obtaining approximation of toxicity. After determination of test concentration, 8 groups of animals were tested at the mean nominal concentrations 54,8 and 102.8 mg potassium /l added to Lake Superior water with 1.2 mg chloride /l. Test concentrations were renewed each week. Test temperature was 18 ±1 oC and photoperiod 18 hours. Reproduction was assessed each week by counting juveniles produced. Three to seven tests were performed and the results of all tests were pooled and statistically analysed.

GLP compliance:

not specified

Analytical monitoring:

yes

Vehicle:

yes

Details on test solutions:

Potassium was added a geometric series of concentrations for obtaining approximation of toxicity. After determination of test concentration, 8 groups of animals were tested at the mean nominal concentrations 54,8 and 102.8 mg potassium /l added to Lake Superior water with 1.2 mg chloride /l. Test concentrations were renewed each week. Test temperature was 18 ±1 oC and photoperiod 18 hours. Reproduction was assessed each week by counting juveniles produced. Three to seven tests were performed and the results of all tests were pooled and statistically analysed.

Test organisms (species):

Daphnia magna

Details on test organisms:

SPECIES #
(NAME): 5 Daphnia magna
(Water Flea)
AGE: 12 h
LIFE STAGE: not reported, unknown
COMMENT: NR

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

21 d

Hardness:

45.3 mg/L CaCO3

Test temperature:

18 °C

pH:

7.74

Dissolved oxygen:

9 mg/L

Reference substance (positive control):

not specified

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

68 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

as potassium

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

97 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

as potassium

Basis for effect:

immobilisation

Remarks on result:

other: 87 mg/l-108 mg/l

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

87 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

as potassium

Basis for effect:

immobilisation

Details on results:

A 21d NOEC of 68 mg/L has been determined for the effects of the test substance (as potassium) on reproduction of the Daphnia magna.
A 21d NOEC of 87 mg/L has been determined for the effects of the test substance (as potassium) on immobilisation of the Daphnia magna.

Validity criteria fulfilled:

yes

Conclusions:

A 21d NOEC of 68 mg/L has been determined for the effects of the test substance (as potassium) on reproduction of the Daphnia magna.
A 21d NOEC of 87 mg/L has been determined for the effects of the test substance (as potassium) on immobilisation of the Daphnia magna.

Reference 2

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

(Q)SAR

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

QSAR prediction: US EPA accepted QSAR method for chemicals properties assessment.

Qualifier:

according to guideline

Guideline:

other: QSAR

Principles of method if other than guideline:

EPI Suite v 4.0/ECOSARv1.00

GLP compliance:

no

Remarks:

not applicable to QSAR models

Analytical monitoring:

not required

Vehicle:

not specified

Test organisms (species):

other: Daphnid species

Details on test organisms:

no further information

Test type:

other: QSAR model

Water media type:

freshwater

Limit test:

no

Total exposure duration:

30 d

Hardness:

not applicable. QSAR model

Test temperature:

not applicable. QSAR model

pH:

not applicable. QSAR model

Dissolved oxygen:

not applicable. QSAR model

Salinity:

not applicable. QSAR model

Details on test conditions:

-Name of test material (as cited in study report:Potassium oxide
CAS Number: 12136-45-7
SMILES : KOK
CHEM : Potash (potassium oxide)
MOL FOR: O1 K2
MOL WT : 94.20
Values used to Generate ECOSAR Profile

Log Kow: -1.380 (EPISuite Kowwin v1.68 Estimate)
Wat Sol: 1E+006 (mg/L, EPISuite WSKowwin v1.43 Estimate)

Reference substance (positive control):

no

Duration:

30 d

Dose descriptor:

NOEC

Effect conc.:

273.134 mg/L

Nominal / measured:

not specified

Conc. based on:

not specified

Basis for effect:

not specified

Remarks on result:

other: cited as a ChV value

Details on results:

Daphnid, 30-day,NOEC for freshwater species cited as ChV (chronic value) = 273.134 mg/L (ppm)

Overview of QSARs estimations on long-term aquatic toxicity of  of Dipotassium oxide/Potassium oxide to Daphnid     

Method	Results	Remarks	Reference
QSAR estimate	Daphnid, 30-day, ChV (chronic value) = 273.134 mg/L (ppm)   Daphnid , 48-hr LC50 =  6675.5 mg/L (ppm)	Reliable with restrictions, QSAR estimated data	ECOSAR Program (v1.00)

ECOSAR QSAR model predicts that NOEC for fresh water species Daphnid cited as ChV (chronic value) would to be 273.134mg/l. 

 

Daphnid, 30-day, ChV (chronic value) = 273.134 mg/L (ppm)

Daphnid , 48-hr LC50 = 6675.5 mg/L (ppm)

 

Validity criteria fulfilled:

yes

Remarks:

US EPA accepted QSAR method for chemicals properties assessment.

Conclusions:

Daphnid, 30-day,NOEC cited as ChV (chronic value) = 273.134 mg/L

Executive summary:

ECOSAR QSAR model predicts that NOEC for fresh water species Daphnid cited as ChV (chronic value) would to be 273.134 mg/l .

Description of key information

A 21d  NOEC of 68 mg/L  has been determined for the effects of the test substance (as potassium) on reproduction of the Daphnia magna.
A 21d  NOEC of 87 mg/L  has been determined for the effects of the test substance (as potassium) on immobilisation of the Daphnia magna.
ECOSAR QSAR model predicts that NOEC for fresh water species Daphnid cited as ChV (chronic value) would to be 273.134 mg/l 
The available data for saltwater invertebrates are limited and to obtaine the value for PNECs for saltwaters is taken account a assesment factor 10 to extrapolate to NOEC following the “Guidance on Information Requirement and Chemical Safety Assessment R.10: Characterisation of dose [concentration]- response for environment”and “Table R.10-5 Assessment factors proposed for deriving PNEC water for saltwater for different data sets”, to account for the possibility that greater taxonomic diversity in the marine environment makes it likely that some marine taxa may be more sensitive than the most sensitive freshwater taxa
21-day NOEC(Salt water) =8.7 mg/L (ppm)
 

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

87 mg/L

Marine water invertebrates

Marine water invertebrates

Effect concentration:

8.7 mg/L

Additional information

A 21d NOEC of 68 mg/L has been determined for the effects of the test substance (as potassium) on reproduction of the Daphnia magna.

A 21d NOEC of 87 mg/L has been determined for the effects of the test substance (as potassium) on immobilisation of the Daphnia magna.

ECOSAR QSAR model predicts that NOEC for fresh water species Daphnid cited as ChV (chronic value) would to be 273.134 mg/l

 

The available data for saltwater invertebrates are limited and to obtaine the value for PNECs for saltwaters is taken account a assesment factor 10 to extrapolate to NOEC following the “Guidance on Information Requirement and Chemical Safety Assessment R.10: Characterisation of dose [concentration]- response for environment”and “Table R.10-5 Assessment factors proposed for deriving PNEC water for saltwater for different data sets”, to account for the possibility that greater taxonomic diversity in the marine environment makes it likely that some marine taxa may be more sensitive than the most sensitive freshwater taxa

 

 

21-day NOEC(Salt water) =8.7 mg/L (ppm)