Magnesium hydrogenorthophosphate

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 30 July 2012 and 09 August 2012.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Trimagnesium bis(orthophosphate)

EC Number:

231-824-0

EC Name:

Trimagnesium bis(orthophosphate)

Cas Number:

7757-87-1

Molecular formula:

Mg3O8P2

IUPAC Name:

trimagnesium diphosphate

Test material form:

solid: particulate/powder

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source:
Harlan Laboratories UK Ltd., Leicestershire, UK.

- Age at study initiation:
Twelve to twenty weeks old

- Weight at study initiation:
2.33 or 2.65 kg

- Housing:
The animals were individually housed in suspended cages. The animals were provided with environmental enrichment items which were considered not to contain any contaminant of a level that might have affected the purpose or integrity of the study.

- Diet:
ad libitum (2030 Teklad Global Rabbit diet supplied by Harlan Laboratories UK Ltd., Oxon, UK)

- 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 3

Test system

Vehicle:

unchanged (no vehicle)

Controls:

other: The left eye remained untreated and was used for control purposes.

Amount / concentration applied:

TEST MATERIAL

- Amount(s) applied (volume or weight with unit): A volume of 0.1 mL of the test item, which was found to weigh approximately 57 mg (as measured by gently compacting the required volume into an adapted syringe) was placed into the conjunctival sac of the right eye, formed by gently pulling the lower lid away from the eyeball.

- Concentration (if solution):
Undiluted and used as supplied

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 reported

Duration of treatment / exposure:

single treatment, eyes were not washed out

Observation period (in vivo):

Approximately 1 hour and 24, 48 and 72 hours following treatment.

Number of animals or in vitro replicates:

2 animals were tested in total. (After consideration of the ocular responses produced in the first treated animal, one additional animals was treated. )

Details on study design:

REMOVAL OF TEST SUBSTANCE

- Washing (if done):
Not applicable

- Time after start of exposure:
Not applicable


SCORING SYSTEM:
Assessment of ocular damage/irritation was made approximately 1 hour and 24, 48 and 72 hours following treatment, according to the numerical evaluation given in Appendix 2, (from Draize J H (1977) "Dermal and Eye Toxicity Tests" In: Principles and Procedures for Evaluating the Toxicity of Household Substances, National Academy of Sciences, Washington DC p.48 to 49).


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:

0

Max. score:

4

Reversibility:

other: not applicable

Remarks on result:

other: Initial pain reaction = 2

Results 2

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

2

Reversibility:

other: not applicable

Results 3

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

24/48/72 h

Score:

1

Max. score:

3

Reversibility:

fully reversible within: 72 hours

Results 4

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24/48/72 h

Score:

0.66

Max. score:

4

Reversibility:

fully reversible within: 72 hours

Irritant / corrosive response data:

Individual and group mean scores for ocular irritation are given in Table 1 and Table 2.
No corneal effects were noted during the test.
Iridial inflammation was noted in both treated eyes one hour after treatment.
Moderate conjunctival irritation was noted in both treated eyes one hour after treatment. Moderate conjunnctival irritation was one in one treated eye and minimal conjunctival irritation was noted in the other treated eye at the 24-hour observation with minimal conjunctival irritation noted in both treated eyes at the 48-hour observation.
Both treated eyes appeared normal by the 72-hour observation.

Other effects:

Bodyweight
Both animals showed expected gain in bodyweight during the study.

Any other information on results incl. tables

Interpretation of Results

The numerical values corresponding to each animal, tissue and observation time were recorded. The data relating to the conjunctivae were designated by the letters A (redness), B (chemosis) and C (discharge), those relating to the iris designated by the letter D and those relating to the cornea by the letters E (degree of opacity) and F (area of cornea involved). For each tissue the score was calculated as follows:

Score for conjunctivae =         (A + B + C) x 2
Score for iris                            =         D x 5
Score for cornea                      =         (E x F) x 5

Using the numerical data obtained a modified version of the system ( Modified Kay and Calandra Interpretation of Eye Irritation Test was used to classify the ocular irritancy potential of the test material. This was achieved by adding together the scores for the cornea, iris and conjunctivae for each time point for each rabbit. The group means of the total scores for each observation were calculated. The highest of these group means (the maximum group mean score) together with the persistence of the reactions enabled classification of the eye irritancy potential of the test material.

If evidence of irreversible ocular damage is noted, the test material will be classified as corrosive to the eye.

 

Table1               IndividualScores and Individual Total Scores for Ocular Irritation

Rabbit Number and Sex	72304Male				72338Male
	IPR= 2				IPR = 2
Time After Treatment	1 Hour	24 Hours	48 Hours	72 Hours	1 Hour	24 Hours	48 Hours	72 Hours
CORNEA
E = Degree of Opacity	0	0	0	0	0	0	0	0
F = Area of Cornea Involved	0	0	0	0	0	0	0	0
Score (E x F) x 5	0	0	0	0	0	0	0	0
IRIS
D	1	0	0	0	1	0	0	0
Score (D x 5)	5	0	0	0	5	0	0	0
CONJUNCTIVAE
A = Redness	2	2	1	0	2	2	1	0
B = Chemosis	2	1	1	0	2	2	0	0
C = Discharge	2	0	0	0	2	1	0	0
Score (A + B + C) x 2	12	6	4	0	12	10	2	0
Total Score	17	6	4	0	17	10	2	0

 

IPR=  Initial pain reaction

 

Table 2               Individual Total Scores and Group Mean Scores for Ocular Irritation

 

Rabbit Number and Sex	Individual Total Scores At:
	1 Hour	24 Hours	48 Hours	72 Hours
72304 Male	17	6	4	0
72338 Male	17	10	2	0
Group Total	34	16	6	0
Group Mean Score	17.0	8.0	3.0	0.0

 

 

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The test material did not meet the criteria for classification as irritant according to Regulation (EC) No. 1272/2008 (EU CLP). This study is conducted according to the appropriate guidelines (OECD 405 ) and under the conditions of GLP and therefore the study is considered to be acceptable and to adequately satisfy both the guideline requirement and the regulatory requirement as a key study for this endpoint. Study is sufficient for classification and labelling purposes, in accordance with Regulation (EC) No. 1272/2008 (EU CLP).