Magnesium potassium fluoride silicate (Mg2.7K0.7Si4O10F2)

Endpoint summary

Description of key information

Two studies are used to draw a conclusion on the acute toxicity of magnesium potassium fluoride silicate (Mg2.7K0.7Si4O10F2).

The acute oral toxicity of the substance was investigated in a non-guideline limit test. Male and female rats received single gavage doses of 5000 mg/kg bw. There were no deaths, no changes to body weight gain during the 14-day observation period, and no macroscopic abnormalities in the organs observed at necropsy. The LD50 was concluded to be > 5000 mg/kg bw.

The acute inhalation toxicity of fluorphlogopite, a substance closely structurally-related to magnesium potassium fluoride silicate (Mg2.7K0.7Si4O10F2), was investigated in a guideline study, conducted in accordance with GLP. Male and female rats were exposed nose-only for 4 hours to an atmosphere containing the test material at a concentration of 5.1 mg/L air. There were no deaths, no clinical signs of toxicity and no changes to body weight gain during the 14-day observation period. No macroscopic abnormalities were observed at necropsy. The LC50 was therefore concluded to be > 5.1 mg/L air. Consequently, the target substance magnesium potassium fluoride silicate (Mg2.7K0.7Si4O10F2) is considered to be non-toxic by the inhalation route.

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:

09 January 1992 - 04 February 1992

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

no guideline followed

Principles of method if other than guideline:

Standard acute oral toxicity method. The test substance was administered to rats by oral gavage at a single dose of 5000 mg/kg bw, and animals were monitored for 14 days.

GLP compliance:

not specified

Test type:

fixed dose procedure

Limit test:

yes

Specific details on test material used for the study:

Nonswellable mica MK (Micromica), supplied by Co-op Chemical Co., Ltd.

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Sankyo Lab Service
- Age at study initiation: 4 weeks
- Weight at study initiation: 91.6 g (males)/81.2 g (females)
- Fasting period before study: 16 hours
- Housing: 5/sex in polycarbonate cages bedded with wood chips
- Diet (e.g. ad libitum): commercial diet ad libitum
- Water (e.g. ad libitum): drinking water ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23 °C (± 2 °C)
- Humidity (%): 50% ± 10%
- Air changes (per hr): 17
- Photoperiod (hrs dark / hrs light): 12 hours (artificial light provided 0600 - 1800)

IN-LIFE DATES: Not specified

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 25% (w/v)
- Amount of vehicle (if gavage): 20 mL/kg
- Justification for choice of vehicle: standard vehicle

Doses:

5000 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

yes

Remarks:

Vehicle only

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: once daily (in the morning)
- Necropsy of survivors performed: yes
- Other examinations performed: macroscopic examination of "organs" [not further specified]

Statistics:

Not specified

Preliminary study:

Not applicable

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Mortality:

No deaths were observed in any treated animals

Clinical signs:

other: No changes were noted in the general condition of any treated animals

Gross pathology:

No macroscopic abnormalities were found in any organs of the rats examined

Other findings:

Food intake in females appeared to be reduced on the day after dosing, then returned to normal; food intake in males was unaffected by treatment. Locomotion activity was normal in all treated rats.

Interpretation of results:

GHS criteria not met

Conclusions:

In an acute oral toxicity limit test, the LD50 of magnesium potassium fluoride silicate (Mg2.7K0.7Si4O10F2) was determined to be > 5000 mg/kg bw.

Executive summary:

The acute oral toxicity of magnesium potassium fluoride silicate (Mg2.7K0.7Si4O10F2) was investigated in a non-guideline limit test. Male and female rats received single gavage doses of 5000 mg/kg bw. There were no deaths, no changes to body weight gain during the 14-day observation period, and no macroscopic abnormalities in the organs observed at necropsy. The LD50 was concluded to be > 5000 mg/kg bw.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

5 000 mg/kg bw

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

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

Adequacy of study:

key study

Study period:

07 August 2008 - 28 October 2008

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Guideline, GLP study conducted on read-across source substance.

Justification for type of information:

A full justification for the use of data on fluorphlogopite as read-across for this substance, magnesium potassium fluoride silicate (Mg2.7K0.7Si4O10F2), is attached to Section 13 of this dossier.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Version / remarks:

12 May 1981

Deviations:

yes

Remarks:

"Values for humidity above the target range were occasionally observed. This deviation was considered to have no impact on the study outcome."

GLP compliance:

yes (incl. QA statement)

Test type:

traditional method

Limit test:

yes

Specific details on test material used for the study:

Identification: Art. 278900 (Fluorphlogopite)
Batch number: 080406.
Particle Size: 10 - 40 µm
Expiry Date: 09 May 2013.

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: At room temperature, protected from direct sunlight.

Species:

rat

Strain:

Wistar

Remarks:

HanRcc:WIST(SPF)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: RCC Ltd, Füllinsdorf, Switzerland.
- Females (if applicable) nulliparous and non-pregnant: Not specified.
- Age at study initiation: Males, 9 weeks; Females, 10 weeks.
- Weight at study initiation: Males, 264.2 - 275.7 g; Females, 207.5 - 224.2 g
- Fasting period before study: Not specified.
- Housing: Groups of max. 5 of the same sex/cage.
- Diet: Standard pelleted diet ad libitum, except during exposure period.
- Water: Tap water ad libitum, except during exposure period.
- Acclimation period: Not specified.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22°C ± 3 °C
- Humidity (%): 30 - 70%
- Air changes (per hr): 10 - 15
- Photoperiod (hrs dark / hrs light): 12 hour photocycle. "A radio program was played during the most of the light period"

IN-LIFE DATES: Not specified. Experimental phase completed 21 Aug 2008 (i.e. animals aged 11 - 12 weeks old)

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

air

Mass median aerodynamic diameter (MMAD):

2.44 µm

Geometric standard deviation (GSD):

2.2

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Rotating brush aerosol generator. Broillet, CR 3020 Equipements SA, Tannay, Switzerland.
- Method of holding animals in test chamber: Restraint tubes.
- Method of particle size determination: Cascade impactor.

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Remarks on duration:

"Single, 4-hour exposure period with five interruptions for a total of 7 minutes for cleaning purpose. Nevertheless, the animals were exposed for a total of 4 hours, as those interruptions were accounted for."

Concentrations:

5.1 mg/L

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Clinical signs recorded once daily. Body weights recorded before exposure (day 1), and subsequently on days 4, 8 and 15 (terminal body weight).
- Necropsy of survivors performed: yes
- Other examinations performed: lungs, trachea, larynx and the head containing the nasopharyngeal tissues were collected and fixed for histopathological examination.

Statistics:

"No statistical analysis was performed as only one dose group was allocated to the study."

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5.1 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Mortality:

All animals survived the scheduled observation period.

Clinical signs:

other: No clinical signs were recorded during the exposure or observation period.

Body weight:

There were no test item-related changes to body weights or body weight gains reported.

Gross pathology:

There were no macroscopic findings.

Interpretation of results:

GHS criteria not met

Conclusions:

In an acute inhalation toxicity limit test, the LC50 of fluorphlogopite, a substance closely structurally-related to magnesium potassium fluoride silicate (Mg2.7K0.7Si4O10F2), was determined to be > 5.1 mg/L air.

Executive summary:

The acute inhalation toxicity of fluorphlogopite, a substance closely structurally-related to magnesium potassium fluoride silicate (Mg2.7K0.7Si4O10F2), was investigated in a guideline study, conducted in accordance with GLP. Male and female rats were exposed nose-only for 4 hours to an atmosphere containing the test material at a concentration of 5.1 mg/L air. There were no deaths, no clinical signs of toxicity and no changes to body weight gain during the 14-day observation period. No macroscopic abnormalities were observed at necropsy. The LC50 was therefore concluded to be > 5.1 mg/L air. Consequently, the target substance magnesium potassium fluoride silicate (Mg2.7K0.7Si4O10F2) is considered to be non-toxic by the inhalation route.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LC50

Value:

5 100 mg/m³ air

Justification for classification or non-classification

In an acute oral toxicity limit test, the LD50 of magnesium potassium fluoride silicate (Mg2.7K0.7Si4O10F2) was determined to be > 5000 mg/kg bw. This exceeds the threshold for Category 4 classification for acute toxicity by the oral route.

In an acute inhalation toxicity limit test, the LC50 of fluorphlogopite, a substance closely structurally-related to magnesium potassium fluoride silicate (Mg2.7K0.7Si4O10F2), was determined to be > 5.1 mg/L air. This exceeds the threshold for Category 4 classification for acute toxicity by the inhalation route, and thus is it concluded that no classification is warranted for the target substance, magnesium potassium fluoride silicate (Mg2.7K0.7Si4O10F2), either.