Oxalic acid

Endpoint summary

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Species:

rabbit

Strain:

New Zealand White

Type of coverage:

not specified

Preparation of test site:

shaved

Vehicle:

physiological saline

Controls:

not required

Duration of treatment / exposure:

Skin preparation:
4 hours before the beginning of the test an area of approximately 240 cm2 has been shaved off from the
back and hips of the animals. An area of about 6 cm2 was used for the application of the assay sample.

Application:
500 mg of the test substance have been applied on the animal’s skin, after humidification with
physiological solution, with a square gauze (2.5 cm x 2.5 cm) and fixed with an elastic bandaging.

Removal of the patches:
The patches have been removed 4 hours after the application.
The exceeding substance has then been cleansed off from skin using a pad soaked with physiological
solution.

Observation period:

OBSERVATIONS
The general conditions of the animals have been daily verified. Skin reactions have been evaluated one
hour after removal of the patches.
The evaluation has been repeated 24, 48 and 72 hours after the application.

Number of animals:

Three rabbits have been used to perform the test.

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 60 minutes

Score:

0

Max. score:

0

Irritation parameter:

erythema score

Basis:

mean

Time point:

24 h

Score:

0

Max. score:

0

Irritation parameter:

erythema score

Basis:

mean

Time point:

48 h

Score:

0

Max. score:

0

Irritation parameter:

erythema score

Basis:

mean

Time point:

72 h

Score:

0

Max. score:

0

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 60 min

Score:

0

Max. score:

0

Irritation parameter:

edema score

Basis:

mean

Time point:

24 h

Score:

0

Max. score:

0

Irritation parameter:

edema score

Basis:

mean

Time point:

48 h

Score:

0

Max. score:

0

Irritation parameter:

edema score

Basis:

mean

Time point:

72 h

Score:

0

Max. score:

0

Other effects:

not other effect

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

On the basis of the results, interpreted according to Official Journal of the European Union
2001/59/EC dated August 6th, 2001 and OECD n° 404 April 24th 2002, the test substance “OXALIC
ACID DI-HYDRATE” must be considered NOT IRRITANT for the skin.

Executive summary:

A GLP Laboratory test has been conducted following the OECD Guideline TG 404 for Skin irritation.

On the basis of the results, interpreted according to Regulation CE 1272/2008, the test substance “OXALIC ACID DI-HYDRATE” must be considered NOT IRRITANT for the skin.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Species:

rabbit

Strain:

New Zealand White

Vehicle:

unchanged (no vehicle)

Controls:

no

Duration of treatment / exposure:

General conditions of the animals have been daily observed.
The eyes have been examined after 1, 24, and 48 hours, from the beginning of the study by means of
an ophthalmoscope.

Observation period (in vivo):

21 days

Number of animals or in vitro replicates:

1

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

other: 1 h

Score:

ca. 2

Max. score:

2

Reversibility:

not reversible

Remarks on result:

other:

Remarks:

A previous check after 1 h was carried out

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

24 h

Score:

ca. 4

Max. score:

4

Reversibility:

not reversible

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

48 h

Score:

ca. 4

Max. score:

4

Reversibility:

not reversible

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

72 h

Remarks on result:

not measured/tested

Remarks:

Evidence of results at 48 h made determination at 72 h unnecessary

Irritation parameter:

iris score

Basis:

animal #1

Time point:

other: 1 h

Score:

ca. 1

Max. score:

1

Reversibility:

not reversible

Remarks on result:

other:

Remarks:

A previous check after 1 h was carried out

Irritation parameter:

iris score

Basis:

animal #1

Time point:

24 h

Score:

ca. 2

Max. score:

2

Reversibility:

not reversible

Irritation parameter:

iris score

Basis:

animal #1

Time point:

48 h

Score:

ca. 2

Max. score:

2

Reversibility:

not reversible

Irritation parameter:

iris score

Basis:

animal #1

Time point:

72 h

Remarks on result:

not measured/tested

Remarks:

Evidence of results at 48 h made determination at 72 h unnecessary

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

other: 1 h

Score:

ca. 3

Max. score:

3

Reversibility:

not reversible

Remarks on result:

other:

Remarks:

A previous check after 1 h was carried out

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

24 h

Score:

ca. 3

Max. score:

3

Reversibility:

not reversible

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

48 h

Score:

ca. 3

Max. score:

3

Reversibility:

not reversible

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

72 h

Remarks on result:

not measured/tested

Remarks:

Evidence of results at 48 h made determination at 72 h unnecessary

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

other: 1 h

Score:

ca. 3

Max. score:

3

Reversibility:

not reversible

Remarks on result:

other:

Remarks:

A previous check after 1 h was carried out

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

24 h

Score:

ca. 4

Max. score:

4

Reversibility:

not reversible

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

48 h

Score:

ca. 4

Max. score:

4

Reversibility:

not reversible

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

72 h

Remarks on result:

not measured/tested

Remarks:

Evidence of results at 48 h made determination at 72 h unnecessary

Other effects:

Cornea: 60 minutes after treatment translucent area were easily discernible and details of iris were slightly obscured. 24 hours later cornea appeared opaque and iris wasn’t discernible through the opacity

Iris: 60 minutes after treatment were observed congestion and swelling, iris was reactive to light (a sluggish reaction). 24 hours later iris wasn’t discernible through the cornea opacity

Conjunctivae:
(Congestion) 60 minutes after the treatment the conjunctivae appeared of a diffuse beefy red. The ymptom persisted for all observation time.

Conjunctivae:
(Chemosis) 60 minutes after treatment the conjunctivae showed a swelling with lids about half closed. 24 hours later a swelling, with lids more than half closed.

Eye reactions have been evaluated according to the values reported in the following table:

 

CORNEA

Opacity - degree of density (the most dense area is chosen for the evaluation)

No ulceration or opacity                                                                                0

sporadic or diffused areas of opacity (different from the slight opacity of normal luminosity)

details of iris clearly visible                                                                         1

Easily discernible translucent area, details of iris slightly obscured                   2

Iridescent area, no details of iris visible, size of pupil barely discernible              3

Opaque cornea, iris not discernible through opacity                                        4

 

IRIS

Normal                                                                                                      0

Notably opened rugae, congestion, swelling, moderate circumcorneal

hyperaemia, or injection, any of these effects or a combination of them, iris stil

reacting to light (slow reaction is positive)                                                     1

No reaction to light, haemorrhage, macroscopic injuries (any or all of these)       2

 

CONJUNCTIVAE

Redness (refers to palpebral and bulbar conjunctivae, cornea and iris)

Normal blood vessels                                                                                   0

Some blood vessels definitely hyperaemic (congested)                                   1

Diffuse, crimson colour, individual vessels not easily discernible                        2

Diffuse beefy red                                                                                          3

 

Chemosis: lids and/or nictitating membranes

No swelling                                                                                                 0

Any swelling above normal (includes nictitating membrane                               1

Obvious swelling with partial ectoprion                                                         2

Swelling with lids about half closed                                                              3

Swelling with lids more than half closed                                                       4

Interpretation of results:

Category 1 (irreversible effects on the eye)

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

On the basis of the results, interpreted according to Official Journal of the European Union 1272/2008
(CLP) dated December 16th, 2008 and OECD n° 405 April 24th 2002, the test substance “OXALIC
ACID” causes IRREVERSIBLE EFFECTS ON THE EYE and must be included in CATEGORY 1.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Additional information

The following table summarizes the data on skin and eye irritation.

 

Study reference	Study type	Result	Remarks	Reliability
Skin irritation
NON_KEY_Scholz, Weigand, 1968_IS	in vivo (rabbit)	Highly irritating	1:10 and 1:30 solution	2
NON KEY_1993_lit_Wahlberg	in vitro (guinea pig)	Dose-response relationship	Development of method for predictive testing and screening	3
KEY_2010_BIOILAB	KEY: In vivo (rabbit)	Not irritant	OECD Guideline, GLP study	1
Eye irritation
NON KEY_Guillot et al, 1982_IS	OECD 405, AFNOR protocol and French cosmetic guideline	Extremely irritating (AFNOR protocol)	Saturated aqueous solution	2
NON KEY_1968_Farbwerke Hoechst AG_Scholz	in vivo (rabbit)	Irritating	1:10 solution (no irritation caused by 1:100 solution)	2
KEY_Eye irritation_BIOLAB	In vivo rabbit	Highly Irritating	OECD Guideline, GLP study	1

 

 

The skin irritation potential was determined for a solid sample of oxalic acid, which was considered not irritating. The eye irritation potential was considered extremely irritating.

Effects on eye irritation: highly irritating

Justification for classification or non-classification

On the basis of the results, interpreted according to Official Journal of the European Union 1272/2008 (CLP) dated December 16th, 2008 and OECD n° 405 April 24th 2002, the test substance “OXALIC ACID” causes IRREVERSIBLE EFFECTS ON THE EYE and must be included in CATEGORY 1.