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

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was performed between 21 February 2007 and 07 March 2007.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Date of inspection: 30/08/05; Date of signature: 12/04/07

Test type:

fixed dose procedure

Limit test:

yes

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

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River (UK) Ltd, Margate, Kent, UK.
- Age at study initiation: eight to twelve weeks
- Weight at study initiation: at least 200g
- Fasting period before study: Not stated in report.
- Housing: suspended solid floor polypropylene cages furnished with woodflakes.
- Diet - ad libitum
- Water - ad libitum
- Acclimation period: at least five days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 to 25°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 14

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

water

Details on dermal exposure:

TEST SITE
- Area of exposure: Back and flanks
- % coverage: 10%
- Type of wrap if used: surgical gauze


REMOVAL OF TEST SUBSTANCE
- Washing (if done): wiped with cotton wool moistened with distilled water to remove any residual test material
- Time after start of exposure: After the 24-hour contact period


TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2000 mg/kg individual weight based on animals body weight
- Concentration (if solution): not applicable
- Constant volume or concentration used: yes
- For solids, paste formed: moistened with distilled water

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 exposure:

24 hours

Doses:

2000 mg/kg.

No. of animals per sex per dose:

5 males and 5 females

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: The animals were observed for deaths or overt signs of toxicity ½, 1, 2 and 4 hours after dosing and subsequently once daily for fourteen days. After removal of the dressings and subsequently once daily for fourteen days, the test sites were examined for evidence of primary irritation. Individual bodyweights were recorded prior to dosing and seven and fourteen days after treatment.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, necrospy

Statistics:

Not stated in report.

Results and discussion

Preliminary study:

Not applicable

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

2 000 mg/kg bw

Remarks on result:

other: 95% confidence limits not given.

Mortality:

There were no deaths.

Clinical signs:

other: There were no signs of systemic toxicity (see Table 1).

Gross pathology:

No abnormalities were noted at necropsy (see Table 5).

Other findings:

- Organ weights:
- Histopathology: Not stated in report.
- Potential target organs: Not stated in report.
- Other observations: Dermal reactions see tables 2 and 3

Any other information on results incl. tables

Table1               Individual Clinical Observations and Mortality Data

Dose Level mg/kg	Animal Number and Sex	Effects Noted After Initiation of Exposure (Hours)				Effects Noted After Initiation of Exposure (Days)
		½	1	2	4	1	2	3	4	5	6	7	8	9	10	11	12	13	14
2000	1-0 Male	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	1-1 Male	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	1-2 Male	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	1-3 Male	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	1-4 Male	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	2-0 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	2-1 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	2-2 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	2-3 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	2-4 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0

0= No signs of systemic toxicity

Table 2               Individual Dermal Reactions - Males

Dose Level mg/kg	Animal Number and Sex	Observation	Effects Noted After Initiation of Exposure (Days)
			1	2	3	4	5	6	7	8	9	10	11	12	13	14
2000	1-0 Male	Erythema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Oedema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	1-1 Male	Erythema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Oedema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	1-2 Male	Erythema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Oedema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	1-3 Male	Erythema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Oedema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	1-4 Male	Erythema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Oedema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0

0= No reactions

Table 3               Individual Dermal Reactions - Females

Dose Level mg/kg	Animal Number and Sex	Observation	Effects Noted After Initiation of Exposure (Days)
			1	2	3	4	5	6	7	8	9	10	11	12	13	14
2000	2-0 Female	Erythema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Oedema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	2-1 Female	Erythema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Oedema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	2-2 Female	Erythema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Oedema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	2-3 Female	Erythema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Oedema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	2-4 Female	Erythema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Oedema	0	0	0	0	0	0	0	0	0	0	0	0	0	0
		Other	0	0	0	0	0	0	0	0	0	0	0	0	0	0

0= No reactions

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The acute dermal median lethal dose (LD50) of the test material in the Sprague Dawley CD strain rat was found to be greater than 2000 mg/kg bodyweight.

Executive summary:

Introduction: The study was performed to assess the acute dermal toxicity of the test material in the Sprague‑Dawley CD strain rat. The method was designed to meet the requirements of the following:

§        OECD Guidelines for the Testing of Chemicals No. 402 “Acute Dermal Toxicity” (adopted)

§        Method B3 Acute Toxicity (Dermal) of Commission Directive 92/69/EEC

Method: A group of ten animals (five males and five females) was given a single, 24-hour, semi‑occluded dermal application of the undiluted test material to intact skin at a dose level of 2000 mg/kg bodyweight. Clinical signs and bodyweight development were monitored during the study. All animals were subjected to gross necropsy.

Mortality: There were no deaths.

Clinical Observations: There were no signs of systemic toxicity.

Dermal Irritation: There were no signs of dermal irritation.

Bodyweight: All animals showed expected gains in bodyweight over the study period.

Necropsy: No abnormalities were noted at necropsy.

Conclusion: The acute dermal median lethal dose (LD₅₀) of the test material in the Sprague‑Dawley CD strain rat was found to be greater than 2000 mg/kg bodyweight.