Lime (chemical), hydraulic

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

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

Adequacy of study:

key study

Study period:

1994-12-22

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Guideline study, reliable with restrictions. - The purity and stability was not given in the test report. Minor deviation with no effect on the study results: - According to the guideline, any effects other than ocular which are observed should be stated. It was not mentioned in this study if other than ocular effects were observed. According to Annexes VII and VIII, point 8.2.1 of Regulation No 1907/2006 information on eye irritation (in vitro or in vivo) of substances shall be provided. Column 2 of Annex VII states that in vitro tests for eye irritation need not be conducted if the criteria for classification as irritating to the eyes are met. In addition, Annex XI specifies rules for adaptation of the standard testing requirements. Point 1.5 of Annex XI permits read-across from substances showing similarities based on, amongst others, common functional groups. This read-across concept is applicable to lime (chemical) hydraulic. When administered to the eye for testing irritating properties (according to the test guideline EC B.5), the main constituent of lime (chemical) hydraulic, calcium hydroxide dissociates into calcium- and hydroxyl ions in aqueous solutions (here in lachrymal fluid), whereas calcium carbonate and silicate remain largely undissolved and are therefore of limited toxicological relevance. Tests on skin and eye irritation are available for calcium hydroxide. According to the test results, calcium hydroxide fulfils the criteria for classification as “risk of serious damage to eyes” and “irritating to skin”. Calcium hydroxide dissociates into Ca2+ and OH– ions. The irritating/damaging effect is due to a pH shift caused by the released hydroxyl ions. Calcium ions are not associated with skin irritation; therefore the pH-shift is the primary effect of lime (chemical) hydraulic involved in eye irritation. In view of the fact that both calcium hydroxide and lime (chemical) hydraulic result in the same “breakdown products” when administered in the appropriate test system, they can be considered as analogue substances, fulfilling criteria (1) and (2) of Annex XI, point 1.5. In addition, the pH of a saturated solution of lime (chemical) hydraulic has been determined at 12.3 (see section 4.8, O'Connor and Woolley, 2010), whereas Ca(OH)2 creates a pH value of 12.4 (Fox, 2010b). Therefore, local effects due to lime (chemical) hydraulic will be approximately equivalent to those arising from Ca(OH)2. Based on the above considerations, lime (chemical) hydraulic is voluntarily proposed to be classified as R38 (irritating to skin) and R41 (risk of serious damage to eye) by read-across, which is therefore a conservative approach. In conclusion, since at least one of the criteria for adaptation of testing requirements specified by column 2 of Annexes VII and VIII, point 8.2 is fulfilled (risk of serious damage to eyes, irritating to skin, by read-across), any further testing is considered to be scientifically unjustified.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

, adopted 1987-02-24

Deviations:

yes

Remarks:

, see "rationale for reliability"

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Calcium dihydroxide

EC Number:

215-137-3

EC Name:

Calcium dihydroxide

Cas Number:

1305-62-0

Molecular formula:

CaH2O2

IUPAC Name:

calcium dihydroxide

Details on test material:

- Name of test material (as cited in study report): Calcium hydroxide (from Laboratoire Central Balthazar et Cotte)
- Physical state: White powder
- Batch No.: 3542
- Storage condition of test material: At ambient temperature
- pH: The pH of the product, at 10 % concentration in distilled water, measured at the International Toxicology Centre, was about 9.
No further information on the test material was stated.

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Elevage Cunicole de Val de Selle, 80160 Prouzel, France
- Weight at study initiation: 2708 g
- Housing: polystyrene cage (35 X 55 X 32 cm or 48.2 X 58 X 36.5 cm) equipped with a trough and bottle.
- Diet (ad libitum): Food in the form of granules " Rabbit maintenance, Reference 112 C" (UAR, 91360 Villemoisson-sur-Orge, France).
- Water (ad libitum): Drinking water
- Acclimation period: 5 days before the start of the study

ENVIRONMENTAL CONDITIONS
- Temperature: 18 +/- 3 °C
- Humidity: 30 to 70 %
- Photoperiod (hrs dark / hrs light): 12/12
No further information on the test animal was stated.

Test system

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied: The lower eyelid was delicately opened, and a single dose of 100 mg of the product as such was introduced in the conjuctival cul-de-sac of the left eye of the animal. The lower and upper lids were maintained in contact for a second to prevent any loss of product. The right eye was administered no product and served as control.
No further information on amount/concentration applied was stated.

Observation period (in vivo):

The eyes were examined 1 hour after the administration of the product.

Number of animals or in vitro replicates:

one male rabbit

Details on study design:

REMOVAL OF TEST SUBSTANCE
The eyes were not rinsed after the administration of the product.

SCORING SYSTEM: Draize scoring system
All other damage observed was recorded.

TOOL USED TO ASSESS SCORE: If necessary the cornea was examined with an ultra-violet lamp. In the case of doubt as to the presence of corneal opacity, the eye was subjected to UV examination (the areas of corneal impairment are distinguished by a very clear fluorescence).
No further information on the study design was stated.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

other: 1 hour after administration

Score:

4

Max. score:

4

Remarks on result:

other: Given the seriousness of the eye lesions observed, the animal was put down for humanitarian reasons, and the product was not tested on the other 2 rabbits.

Results 2

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

other: 1 hour after administration

Score:

3

Max. score:

3

Remarks on result:

other: Given the seriousness of the eye lesions observed, the animal was put down for humanitarian reasons, and the product was not tested on the other 2 rabbits.

Irritant / corrosive response data:

Very severe eye reactions were observed 1 hour after the treatment, with pronounced chemosis (score:3), necrotised appearance of the conjunctiva, whitish watering and total opacity of the cornea, showing nacreous appearance. The iris was no longer visible.
Given the seriousness of the eye lesions observed, the animal was put down for humanitarian reasons, and the product was not tested on the other 2 rabbits.

Applicant's summary and conclusion

Interpretation of results:

irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Based on the results of the study described in this report and applying read-across from calcium hydroxide, lime (chemical), hydraulic is voluntarily proposed to be classified as R38 (irritating to skin) and R41 (risk of serious damage to eye) according to Directive 67/548/EEC and subsequent regulations by read-across. This is a conservative approach following the precautionary principle, in view of the weaker pH effect of calcined dolomite.