Magnesium chloride

Endpoint summary

Description of key information

Acute toxicity studies have been conducted with magnesium chloride hexahydrate via the oral and dermal route.

The results have been corrected to magnesium chloride anhydrous.

Thus:

- For oral acute toxicity, the LC50 was > 2330 mg MgCl2/kg bw for Wistar rats (OECD 423).

- For dermal acute toxicity, the LC50 was considered as > 2000 mg MgCl2/kg bw for Wistar rats (OECD 402 and toxicity data).

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

October 2009 till december 2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Version / remarks:

17 December 2001

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Version / remarks:

December 2002

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)

Version / remarks:

30 May 2008

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

no

Specific details on test material used for the study:

- Name of test material (as cited in study report): Magnesium chloride hexahydrate
- EC-Number: 232-094-6
- Physical state: Colourless; Solid, crystals
- Stability after opening: Instable after repeated contact to air
- Storage condition of test material: At room temperature, in a tightly closed package.
- pH: 5.5 - 7.0 (5% solution at 20 °C)
- Solvent: Water
No further information on the test material was stated.

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

Species/strain: Healthy rats, WISTAR rats Crl: WI(Han) (Full-Barrier)
Source: Charles River, 97633 Sulzfeld, Germany
Sex: female, non-pregnant, nulliparous
Age at the beginning of the study: 8 - 12 weeks old
Body weight at the beginning of the study: animals no. 1 – 3, step 1: 151 – 158 g and animals no. 4 – 6, step 2: 161 – 170 g;
The animals were derived from a controlled full barrier maintained breeding system (SPF).

Housing and Feeding Conditions: full-barrier in an air-conditioned room, temperature: 22 (+/-3) °C, relative humidity: 55 (+/-10) %, artificial light, sequence being 12 hours light, 12 hours dark, air change: 10 x / hour, free access to Altromin 1324 maintenance diet, free access to tap water, sulphur acidified to a pH value of approx. 2.8, the animals were kept in groups in IVC cages, type III H, polysulphone cages on Altromin saw fibre bedding, adequate acclimatisation period (at least five days).

Route of administration:

oral: gavage

Vehicle:

water

Remarks:

Aqua ad injectionem

Details on oral exposure:

The test item was administered at a single dose by gavage using a feeding tube.
The test item was administered at a dose volume of 5 mL/kg body weight.

Doses:

2000 mg/kg body weight

No. of animals per sex per dose:

3 per step (two steps) (Total: 6 female rats)

Control animals:

no

Details on study design:

The animals were marked for individual identification by tail painting.
Prior to the administration, a detailed clinical observation was made of all animals.
Prior to the administration food was withheld from the test animals for 16 to 19 hours (access to water was permitted). Following the period of fasting, the animals were weighed and the test item was administered. Food was provided again approximately 3-4 hours post dosing.

All animals were observed for 14 days after dosing for general clinical signs, morbidity and mortality.
The animals were weighed on day 1 (prior to the administration) and on days 8 and 15.
A careful clinical examination was made several times on the day of dosing (at least once during the first 30 minutes and with special attention given during the first 4 hours post-dose). Thereafter, the animals were observed for clinical signs once daily until the end of the observation period. All abnormalities were recorded.
Cageside observations included changes in the skin and fur, eyes and mucous membranes. Also respiratory, circulatory, autonomic and central nervous systems and somatomotor activity and behaviour pattern were examined. Particular attention was directed to observations of tremor, convulsions, salivation, diarrhea, lethargy, sleep and coma.
At the end of the observation period, the animals were sacrificed with an overdosage of pentobarbital injected intraperitoneally at a dosage of approx. 8 mL/kg bw. All animals were subjected to gross necropsy. All gross pathological changes were recorded.

Statistics:

No

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: LD50 cut off

Key result

Sex:

female

Dose descriptor:

LD0

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

All animals survived until the end of the study.

Clinical signs:

other: All animals survived without showing any signs of toxicity.

Gross pathology:

At necropsy, no macroscopical findings were observed in any animal of any step.

Table1: Results per Step

Step	Sex/no.	Dose (mg/kg)	Number of animals	Number of intercurrent deaths
1	f/1-3	2000	3	0
2	f/4-6	2000	3	0

Table 2: Absolute Body Weights in g and Body Weight Gain in %

Animal no. / sex	g Day 1	g Day 8	g Day 15	% Day 1-15
Step 1 (2000 mg/kg bw)
1 / female	158	182	192	+22
2 / female	155	176	187	+21
3 / female	151	165	171	+13
Step 2 (2000 mg/kg bw)
4 / female	170	203	215	+26
5 / female	161	182	199	+24
6 / female	162	194	204	+26

Table 3: Macroscopical Findings - Individual Data

Animal no. / sex	Organ	Findings at the necropsy
1 / female	--	NAD
2 / female	--	NAD
3 / female	--	NAD
4 / female	--	NAD
5 / female	--	NAD
6 / female	--	NAD

Interpretation of results:

GHS criteria not met

Conclusions:

Under the condition of this test, a single oral application of Magnesium chloride hexahydrate to rats at a dose of 2000 mg/kg body weight was associated with no signs of toxicity or mortality. The median lethal dose of Magnesium chloride hexahydrate after a single oral administration to female rats, observed over a period of 14 days, is 5000 mg/kg body weight (LD50 cut off).

Executive summary:

The study was performed according to the OECG guideline 423 and was GLP compliant.

Two groups, each of three female WISTAR Crl: WI(Han) rats, were treated with Magnesium Chloride hexahydrate by oral gavage administration at a dosage of 2000 mg/kg body weight.

The test item was dissolved in a vehicle (Aqua ad injectionem (sterile water)) at a concentration of 0.4 g/mL and administered at a dose volume of 5 mL/kg.

The animals were observed on delivery, on inclusion in the study and before administration for mortality/morbidity and other clinical signs. All animals were examined for clinical signs several times on the day of dosing and once daily until the end of the observation period. Their body weights were recorded on day 1 (prior to the administration) and on days 8 and 15. All animals were necropsied and examined macroscopically.

 

Throughout the 14-day observation period, all animals survived until the end of the study without showing any signs of toxicity and the weight gain of the animals was within the expected range. Also at necropsy, no macroscopical findings were observed in any animal of any step.

In conclusion, the median lethal dose of Magnesium chloride hexahydrate after a single oral administration to female rats, observed over a period of 14 days is 5000 mg/kg body weight (LD50 cut off).

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 330 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

February 2010 till May 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

yes

Remarks:

One female animal was slightly below 200 g but this animal was only of 2 g below the accepted range, it was included in the study.

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

One female animal was slightly below 200 g but this animal was only of 2 g below the accepted range, it was included in the study.

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Specific details on test material used for the study:

- Name of test material (as cited in study report): Magnesium chloride hexahydrate
- EC-Number: 232-094-6
- Physical state: Colourless; Solid, crystals
- Stability after opening: Instable after repeated contact to air
- Storage condition of test material: At room temperature, in a tightly closed package.
- pH: 5.5 - 7.0 (5% solution at 20 °C)
- Solvent: Water
No further information on the test material was stated.

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Species/strain: Healthy rats, WISTAR Crl: WI(Han) (Full-Barrier)
Source: Charles River, 97633 Sulzfeld, Germany
The female animals were nulliparous and non-pregnant.
Body weight at the beginning of the study: females: 198 - 222 g, males: 241 – 262 g
Age at the beginning of the study: females: 18 - 19 weeks old, males: 8 -9 weeks old
The animals were derived from a controlled full-barrier maintained breeding system (SPF).

Housing and Feeding Conditions: full barrier in an air-conditioned room, temperature: 22 (+/-3) °C, relative humidity: 55 (+/- 10)%, artificial light, sequence being 12 hours light, 12 hours dark, air change: 10 x / hour, free access to Altromin 1324 maintenance diet for rats and mice, free access to tap water, sulphur acidified to a pH value of approx. 2.8 (drinking water, municipal residue control, microbiological control at regular
intervals), the animals were kept individually in IVC cages, type III H, polysulphone cages on Altromin saw fibre bedding, adequate acclimatisation period.

Type of coverage:

semiocclusive

Vehicle:

water

Remarks:

Aqua ad injectionem

Details on dermal exposure:

Approximately 24 hours before the test, the fur was removed from the dorsal area of the trunk by using an electric clipper. Care was taken to avoid abrading the skin, and only animals with healthy intact skin were used.
No less than 10 % of the body surface was cleared for the application.
The test item was applied at a single dose, uniformly over an area which was approx. 10 % of the total body surface.

Duration of exposure:

The test item was held in contact with the skin throughout a 24-hour period. At the end of the exposure period residual test item was not removed.

Doses:

2000 mg/kg body weight

No. of animals per sex per dose:

5 males and 5 females

Control animals:

no

Details on study design:

Prior to the application, a detailed clinical observation was made of all animals.
All animals were observed for 14 days after dosing.
The animals were weighed on day 1 (prior to the application) and on days 8 and 15.
A careful clinical examination was made several times on the day of dosing (at least once during the first 30 minutes and with special attention given during the first 4 hours post-dose). As soon as symptoms were noticed they were recorded. Thereafter, the animals were observed for clinical signs once daily until the end of the observation period. All abnormalities were recorded.
Cageside observations included changes in the skin and fur, eyes and mucous membranes. Also respiratory, circulatory, autonomic and central nervous systems and somatomotor activity and behaviour pattern were examined. Attention was directed to observations of tremors, convulsions, salivation, diarrhea, lethargy, sleep and coma.
At the end of the observation period, the animals were sacrificed by an overdosage of pentobarbital injected intraperitoneally. All animals were subjected to gross necropsy. All gross pathological changes were recorded.

Statistics:

Signs of erythema and oedema were assessed using the scoring system laid down in OECD Guideline 404.

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No

Clinical signs:

other: The test item showed slight signs of dermal irritation (slight scratches) after a single dose application for one female (n°14) on day 3 and 4. The clinical signs observed were seen only on the day of application and may partly be due to the stress induc

Gross pathology:

At necropsy, female no. 14 showed changes of the tissue on the large intestine, which was filled with liquid. As this finding was seen in only one animal and was not associated with any specific clinical signs, this finding was most probably not test item related.

Other findings:

No

Absolute Body Weights in g and Body Weight Gain in %

Animal No. / Sex	Day 1	Day 8	Day 15	% Day 1 - 15
11 female	222	219	219	-1
12 female	201	208	213	6
13 female	218	216	215	-1
14 female	214	217	215	0.5
15 female	198	195	200	1
21 male	262	288	315	20
22 male	256	275	303	18
23 male	241	268	291	21
24 male	244	264	286	17
25 male	247	273	302	22

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of this study, the dermal LD50 was determined to be > 2000 mg Magnesium chloride hexahydrate/kg body weight.

Executive summary:

This study was a limit test of the acute dermal method (OECD 402) in male and female Wistar rats carried out according to the OECD guideline 402.

Under the conditions of the present study, single dermal application of the test item Magnesium chloride hexahydrate to rats at a dose of 2000 mg/kg body weight was associated with slight signs of toxicity and irritation, but no mortality.

The dermal LD50 was determined to be > 2000 mg Magnesium chloride hexahydrate/kg body weight.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Additional information

The acute toxicity studies were conducted for the oral and dermal route. The inhalation route is not appropriate due to the nature of the substance (magnesium chloride is deliquescent, it does not stay under a granular form and hydrates quickly).

For oral acute toxicity

All the studies indicate a LD50 higher than 2000 mg/kg bw. The key study (Allingham, 2009 - Reliability 1) is a acute toxic class method (OECD 423) in female Wistar rats. The LD50 cut off was > 5000 mg/kg bw for the hydrate form. For the anhydrous form, the LD50 is considered to be > 2330 mg/kg bw.

For dermal acute toxicity

The key study (Leon, 2010 - Reliability 1) is a limit test of the acute dermal method (OECD 402) in male and female Wistar rats. The LD50 was > 2000 mg/kg bw for the hydrate form. For the anhydrous form, on the basis of

• no significant effect (clinical signs, bodyweight, gross pathology) observed on the 5 male and 5 female rats under the conditions of the OECD 402 study,
• The LD50 > 932 mg/kg bw for the anhydrous form and no mortality observed (for ten rats) under the conditions of the OECD 402 study,
• no irritation effect (local effect) of MgCl2 under the condition of GPL studies (402 and Episkin),
• for several metals (Zn, Ni, Cd, Sb, Cu, Pb), the penetration of the dermis by dissolved metal cations generally low, i.e. in the range of 0.1 -1% (HERAG, Helth Risk Assessment Guidance for metals, 2006),

it was concluded that LD50 was > 2000 mg/kg bw.

Justification for classification or non-classification

On the basis of LD50 values and some data for the dermal acute toxicity (toxicity and toxicokinetics data), the MgCl2 was not classified for acute toxicity under the CLP regulation 1272/2008.