Magnesium hydroxide sulfate (Mg6(OH)10(SO4)), hydrate (1:3)

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was performed between 13 November 2006 and 28 November 2006.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Date of inspection: 30/08/05; Date of signature: 14/12/06

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

483-390-9

EC Name:

-

Cas Number:

12508-61-1

Molecular formula:

H16Mg6O17S

IUPAC Name:

hexamagnesium(2+) trihydrate decahydroxide sulfate

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Not stated in report.
- Age at study initiation: twelve to twenty weeks old.
- Weight at study initiation: 2.0 to 3.5 kg
- Housing: The animals were individually housed in suspended cages.
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: at least five days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17 to 23°C
- Humidity (%): 30 to 70%
- Air changes (per hr): at least fifteen changes per hour
- Photoperiod (hrs dark / hrs light): twelve hours continuous light (06:00 to 18:00) and twelve hours darkness.


IN-LIFE DATES: From: Day 1 To: Day 7

Test system

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.1 ml of the test material, which was found to weigh approximately 30 mg (as measured by gently compacting the required volume into an adapted syringe)
- Concentration (if solution): not applicable


VEHICLE
- Amount(s) applied (volume or weight with unit): not applicable
- Concentration (if solution): not applicable
- Lot/batch no. (if required): not applicable
- Purity: not applicable

Duration of treatment / exposure:

7 days

Observation period (in vivo):

7 days

Number of animals or in vitro replicates:

3

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done): not stated in report if washing was done.
- Time after start of exposure: not stated in report


SCORING SYSTEM: Kay and Calandra


TOOL USED TO ASSESS SCORE: Examination of the eye was facilitated by the use of the light source from a standard ophthalmoscope

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24/48/72 h

Score:

1

Max. score:

1

Reversibility:

fully reversible within: 7 days

Results 2

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Score:

1

Max. score:

1

Reversibility:

fully reversible within: 72 hours

Results 3

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24/48/72 h

Score:

1.33

Max. score:

2

Reversibility:

fully reversible within: 7 days

Results 4

Irritation parameter:

conjunctivae score

Remarks:

: Redness

Basis:

mean

Time point:

24/48/72 h

Score:

2

Max. score:

2

Reversibility:

fully reversible within: 7 days

Any other information on results incl. tables

Individual and group mean scores for ocular irritation are given in Table1and Table2.

White residual test material was noted in all treated eyes at the 1-hour observation.

Scattered or diffuse corneal opacity was noted in one treated eye at the 24-hour observation, in all treated eyes at the 48-hour observation and persisted in one treated eye at the 72‑hour observation.

Iridial inflammation was noted in all treated eyes one hour after treatment and at the 24-hour observation and in one treated eye at the 48-hour observation.

Moderate conjunctival irritation was noted in all treated eyes one hour after treatment and at the 24, 48 and 72-hour observations.

All treated eyes appeared normal at the 7-day observation.

Table1               IndividualScores and Individual Total Scoresfor Ocular Irritation

Rabbit Number and Sex	65132 Male					65198 Male					65191 Male
	IPR= 2					IPR = 2					IPR = 2
Time After Treatment	1 Hour	24 Hours	48 Hours	72 Hours	7 Days	1 Hour	24 Hours	48 Hours	72 Hours	7 Days	1 Hour	24 Hours	48 Hours	72 Hours	7 Days
CORNEA
E = Degree of Opacity	0	1	1	0	0	0	0	1	0	0	0	1	1	1	0
F = Area of Cornea Involved	0	2	1	0	0	0	0	1	0	0	0	2	1	1	0
Score (E x F) x 5	0	10	5	0	0	0	0	5	0	0	0	10	5	5	0
IRIS
D	1	1	0	0	0	1	1	1	0	0	1	1	0	0	0
Score (D x 5)	5	5	0	0	0	5	5	5	0	0	5	5	0	0	0
CONJUNCTIVAE
A = Redness	2	2	2	2	0	2	2	2	2	0	2	2	2	2	0
B = Chemosis	2	2	1	1	0	2	2	1	1	0	2	2	1	1	0
C = Discharge	2Re	2	1	1	0	2Re	2	1	1	0	2Re	2	1	1	0
Score (A + B + C) x 2	12	12	8	8	0	12	12	8	8	0	12	12	8	8	0
Total Score	17	27	13	8	0	17	17	18	8	0	17	27	13	13	0

IPR= Initial pain reaction

Re= White residual test material in the treated eye

Table2               Individual Total Scores and Group Mean Scoresfor Ocular Irritation

Rabbit Number and Sex	Individual Total Scores At:
	1 Hour	24 Hours	48 Hours	72 Hours	7 Days
65132 Male	17	27	13	8	0
65198 Male	17	17	18	8	0
65191 Male	17	27	13	13	0
Group Total	51	71	44	29	0
Group Mean Score	17.0	23.7	14.7	9.7	0.0

 

IPR= Initial pain reaction

Re= White residual test material in the treated eye

Applicant's summary and conclusion

Interpretation of results:

Category 2 (irritating to eyes) based on GHS criteria

Conclusions:

The test material produced a maximum group mean score of 23.7 and was classified as a MODERATE IRRITANT (CLASS 5 ON A 1 TO 8 SCALE) to the rabbit eye according to a modified Kay and Calandra classification system.
The substance is classified as an eye irritant (Category 2: Causes serious eye irritation) under the EU CLP Regulation (EC) No 1272/2008.

Executive summary:

Introduction. 

The study was performed to assess the irritancy potential of the test material to the eye of the New Zealand White rabbit. The method was designed to meet the requirements of the following:

§        OECD Guidelines for the Testing of Chemicals No. 405 “Acute Eye Irritation/Corrosion” (adopted)

§        Method B5 Acute Toxicity (Eye Irritation) of Commission Directive 2004/73/EC

Result. 

A single application of the test material to the non-irrigated eye of three rabbits produced scattered or diffuse corneal opacity, iridial inflammation and moderate conjunctival irritation. All treated eyes appeared normal at the 7-day observation.

Conclusion. 

The test material produced a maximum group mean score of 23.7 and was classified as a MODERATE IRRITANT (CLASS 5 ON A 1 TO 8 SCALE) to the rabbit eye according to a modified Kay and Calandra classification system.

The substance is classified as an eye irritant (Category 2: Causes serious eye irritation) under the EU CLP Regulation (EC) No 1272/2008.