Dipotassium oxalate

Endpoint summary

Description of key information

Oral (no guideline followed), rat: LD50 = 375 mg/kg bw (female)

(RA from CAS 144-62-7)

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1977

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Remarks:

(no details on test animals and environmental conditions were given

Qualifier:

no guideline followed

Principles of method if other than guideline:

Single oral dose toxicity was usually determined by the method of Smyth et al. (1962) in which the LD50 and its 95% confidence limits are estimated by the moving average technique (Thompson, 1947; Weil, 1952). Occasionally enough data were obtained to use the probit method (Finney, 197 1) for calculation.

GLP compliance:

no

Test type:

standard acute method

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 200 - 300 g
- Diet: Purina Formulab Chow 5008

Route of administration:

oral: unspecified

Vehicle:

water

Control animals:

not specified

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

7.5 mL/kg bw

Based on:

test mat.

Remarks:

5% (w/v) in aqueous solution

Key result

Sex:

male

Dose descriptor:

LD50

Effect level:

9.5 mL/kg bw

Based on:

test mat.

Remarks:

5% (w/v) in aqueous solution

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

375 mg/kg bw

Based on:

test mat.

Remarks:

100% by calculation

Key result

Sex:

male

Dose descriptor:

LD50

Effect level:

475 mg/kg bw

Based on:

test mat.

Remarks:

100% by calculation

Interpretation of results:

other: Category 4 based on CLP/EU GHS criteria, according to Regulation (EC) No 1272/2008

Conclusions:

CLP: Acute Oral 4, H302 (Annex VI harmonized classification)

The available data on acute toxicity (oral) are in consistency with the harmonized classification according to Regulation (EC) 1272/2008, Annex VI.

Reference 2

Endpoint:

acute toxicity: oral

Type of information:

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

Adequacy of study:

weight of evidence

Justification for type of information:

Please refer to analogue justification provided in IUCLID section 13

Reason / purpose for cross-reference:

read-across source

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

375 mg/kg bw

Based on:

test mat.

Remarks on result:

other: Source, Vernot et al., 1977

Key result

Sex:

male

Dose descriptor:

LD50

Effect level:

475 mg/kg bw

Based on:

test mat.

Remarks on result:

other: Source, Vernot et al., 1977

Interpretation of results:

other: Category 4 based on CLP/EU GHS criteria, according to Regulation (EC) No 1272/2008

Conclusions:

CLP: Acute toxicity, Cat. 4, H302 (Annex VI harmonized classification)

The available data on acute toxicity (oral) of the source substance are in consistency with the harmonized classification according to Regulation (EC) 1272/2008, Annex VI (Index No. 607-006-00-8).
Applying the RA-A approach and in consistency with the harmonized classification of the target substance according to Regulation (EC) 1272/2008, Annex VI (Index No. 607-007-00-3), the target substance meets the criteria for classification as Acute Tox. Cat. 4, oral, H302.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

375 mg/kg bw

Quality of whole database:

The available information comprises an adequate and reliable study (Klimisch score 2) from a reference substance with similar structure and intrinsic properties. Read-across is justified based on structural similarity and similarities in physico-chemical properties. The selected studies are thus sufficient to fulfil the standard information requirements set out in Annex VII, 8.5, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006.

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Justification for read-across

There are no reliable data available regarding acute toxicity for either dipotassium oxalate monohydrate (CAS 6487-48-5) or dipotassium oxalate anhydrate (CAS 583-52-8). Read-across from an appropriate substance (oxalic acid (CAS 144-62-7) is conducted in accordance with Regulation (EC) No 1907/2006, Annex XI, 1.5. in order to fulfil the standard data requirements defined in Regulation (EC) No 1907/2006, Annex VII, 8.5. Common functional groups, structural similarities and comparable toxicological properties (according to the joint consideration in Annex VI to CLP) of the source and target substance are the basis of read-across. A detailed justification for the analogue read-across approach is provided in the technical dossier (see IUCLID Section 13).

Acute oral toxicity

CAS 144-62-7

Acute toxicity of oxalic acid was tested in male and female rats (Vernot et al., 1977). In this publication acute toxicity data for some organic and inorganic compounds and aqueous solutions (among them 5% (w/v) oxalic acid) were tested. The test substance 5% (w/v) aqueous solution of oxalic acid was orally administered. Based on the result of this study, a LD50 of 375 and 475 mg/kg bw was derived for females and males, respectively.

A poisoning incident was described by Umezum (1980). A Japanese 26-year old woman took 30 g of oxalic acid. 10 hours after hospitalisation, the patient died. The patient complained about a burning sensation in the throat, dizziness, diarrhoea and cold sweat as well as shock symptom (no further details were given in the report). Following examination, corrosion of the tongue, inflammation of the esophagus, atony and inflammation of the stomach, and black digested material in stomach and small intestine was observed (please refer to 7.10.3).

Justification for classification or non-classification

According to Article 13 of Regulation (EC) No. 1907/2006 "General Requirements for Generation of Information on Intrinsic Properties of substances", information on intrinsic properties of substances may be generated by means other than tests e.g. from information from structurally related substances (grouping or read-across), provided that conditions set out in Annex XI are met. Annex XI, "General rules for adaptation of this standard testing regime set out in Annexes VII to X” states that “substances whose physicochemical, toxicological and ecotoxicological properties are likely to be similar or follow a regular pattern as a result of structural similarity may be considered as a group, or ‘category’ of substances. This avoids the need to test every substance for every endpoint". Since the analogue concept is applied to dipotassium oxalate, data will be generated from information on reference source substance(s) to avoid unnecessary animal testing. Additionally, once the analogue read-across concept is applied, substances will be classified and labelled on this basis.

Applying the RA-A approach and in consistency with the harmonized classification of the target substance according to Regulation (EC) 1272/2008, Annex VI (Index No. 607-007-00-3), the target substance dipotassium oxalate meets the criteria for classification as Acute oral Tox. Cat. 4, H302 and Acute dermal Tox., Cat. 4, H312.