Samarium

Endpoint summary

Description of key information

Acute Oral Toxicity

In accordance with Section 2 of REACH Annex XI, this study does not need to be conducted as testing is not technically possible. It is not possible to produce a powdered form of the substance suitable for testing as the powdered form is flammable.

It is not considered appropriate to test an extract following dissolution of the massive form in aqueous media as the substance is highly insoluble meaning there would be an insufficient concentration of dissolved metal ions in the extract solution to be tested.

- Supporting information on the read-across substance, samarium oxide

- 1990 Study:

Under the conditions of the study the acute oral LD50 to male and female Sprague dawley rats was determined to be in excess of 5 000 mg/kg.

- 1963 Study:

Under the conditions of the study the acute oral LD50 to female rats was determined to be in excess of 1 000 mg/kg.

Since the surface of samarium metal oxidises on contact with air to form an outer layer of samarium oxide, it is considered appropriate to read across information from samarium oxide to the metal where testing on the metal is not technically possible.

Acute Inhalation Toxicity

In accordance with Section 2 of REACH Annex XI, this study does not need to be conducted as testing is not technically possible. It is not possible to produce a powdered form of the substance suitable for testing as the powdered form is flammable.

It is not possible to generate an atmosphere of test material that would be suitable for testing. The smallest size of substance that can be generated without the risk of fire would be too dense to produce a test atmosphere for testing.

Furthermore, exposure of humans via inhalation will not occur as the substance is not used in powdered form and the powdered form of the substance will not be generated during substance use.

Acute Dermal Toxicity

In accordance with Section 2 of REACH Annex XI, this study does not need to be conducted as testing is not technically possible. It is not possible to produce a powdered form of the substance suitable for testing as the powdered form is flammable.

It is not considered appropriate to test an extract following dissolution of the massive form in aqueous media as the substance is highly insoluble meaning there would be an insufficient concentration of dissolved metal ions in the extract solution to be tested.

As the substance is highly insoluble, the study is also omitted on grounds there would be no potential for a significant rate of absorption through the skin.

Furthermmore, information from an acute oral toxicity study conducted with the read across substance, samarium oxide, suggests the substance does not meet the criteria for classification as acute toxicity or STOT SE (acute oral LD50 > 5 000 mg/kg).

Since the surface of samarium metal oxidises on contact with air to form an outer layer of samarium oxide. It is therefore considered appropriate to read across information from samarium oxide to the metal where testing on the metal is not technically possible.

- Supporting information on the read-across substance, samarium oxide

Under the conditions of the study, the acute dermal LD50 to male and female Sprague Dawley rats was determined to be in excess of 2 000 mg/kg bw.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: oral

Data waiving:

study technically not feasible

Justification for data waiving:

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
In accordance with Section 2 of REACH Annex XI, this study does not need to be conducted as testing is not technically possible. It is not possible to produce a powdered form of the substance suitable for testing as the powdered form is flammable.
It is not considered appropriate to test an extract following dissolution of the massive form in aqueous media as the substance is highly insoluble meaning there would be an insufficient concentration of dissolved metal ions in the extract solution to be tested.

Reference 2

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

not reported

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Justification for type of information:

The surface of samarium metal oxidises on contact with air to form an outer layer of samarium oxide. It is therefore considered appropriate to read across information from samarium oxide to the metal where testing on the metal is not technically possible.

Reason / purpose for cross-reference:

other: read-across target

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Principles of method if other than guideline:

A Limit Dose of 5.0 g/kg was administered by gavage (50 % w/w solution in distilled water) to 10 fasted Sprague-Dawley rats (200-300 g) using 5/sex. Animals were observed for clinical signs for 14 days following dosing.

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Route of administration:

oral: gavage

Vehicle:

other: distilled water

Details on oral exposure:

DOSAGE
5.0 g/kg as a 50 % w/w solution in distilled water

Doses:

5.0 g/kg

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 other: mg/kg

Based on:

test mat.

Interpretation of results:

other: Not classified in accordance with EU criteria

Conclusions:

Under the conditions of the study the acute oral LD50 to male and female Sprague dawley rats was determined to be in excess of 5 000 mg/kg.

Executive summary:

The acute oral toxicity of the test material, samarium oxide, was investigated.

During the study, a Limit Dose of 5.0 g/kg was administered by gavage (50 % w/w solution in distilled water) to 10 fasted Sprague-Dawley rats (200-300 g) using 5/sex. Animals were observed for clinical signs for 14 days following dosing.

Under the conditions of the study the acute oral LD50 to male and female Sprague dawley rats was determined to be in excess of 5 000 mg/kg.

Reference 3

Endpoint:

acute toxicity: oral

Type of information:

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

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study conducted on read-across material

Justification for type of information:

The surface of samarium metal oxidises on contact with air to form an outer layer of samarium oxide. It is therefore considered appropriate to read across information from samarium oxide to the metal where testing on the metal is not technically possible.

Reason / purpose for cross-reference:

read-across source

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 other: mg/kg

Based on:

test mat.

Reference 4

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

not reported

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Justification for type of information:

The surface of samarium metal oxidises on contact with air to form an outer layer of samarium oxide. It is therefore considered appropriate to read across information from samarium oxide to the metal where testing on the metal is not technically possible.

Reason / purpose for cross-reference:

other: read-across target

Qualifier:

no guideline followed

Principles of method if other than guideline:

A single 1 000 mg/kg dose of test material was administered, as a 50 % aqueous solution, by gavage to a group of female rats. The rats were subsequently observed for a period of 30 days.

GLP compliance:

no

Remarks:

Study pre-dates GLP

Test type:

standard acute method

Limit test:

yes

Species:

rat

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 190 - 250 g
- Diet: Ad libitum (Rockland Rat Diet)
- Water: Ad libitum


ENVIRONMENTAL CONDITIONS
Animals were housed in air-conditioned quarters.

Route of administration:

oral: gavage

Details on oral exposure:

DOSAGE PREPARATION
The samarium oxide dose was prepared as a 50 % suspension by homogenisation in an aqueous 0.2 % solution of carboxymethylcellulose.

Doses:

1 000 mg/kg

Details on study design:

- Duration of observation period following administration: 30 days

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 1 000 other: mg/kg

Based on:

test mat.

Interpretation of results:

study cannot be used for classification

Conclusions:

Under the conditions of the study the acute oral LD50 to female rats was determined to be in excess of 1 000 mg/kg.

Executive summary:

The acute oral toxicity of the test material, samarium oxide, was investigated.

During the study, a single 1 000 mg/kg dose of test material was administered, as a 50 % aqueous solution, by gavage to a group of female rats. The rats were subsequently observed for a period of 30 days.

Under the conditions of the study the acute oral LD50 to female rats was determined to be in excess of 1 000 mg/kg.

Reference 5

Endpoint:

acute toxicity: oral

Type of information:

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

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study conducted on read-across material

Justification for type of information:

The surface of samarium metal oxidises on contact with air to form an outer layer of samarium oxide. It is therefore considered appropriate to read across information from samarium oxide to the metal where testing on the metal is not technically possible.

Reason / purpose for cross-reference:

read-across source

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 1 000 other: mg/kg

Based on:

test mat.

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

Data waiving:

study technically not feasible

Justification for data waiving:

the study does not need to be conducted because exposure of humans via inhalation is not likely taking into account the vapour pressure of the substance and/or the possibility of exposure to aerosols, particles or droplets of an inhalable size

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
In accordance with Section 2 of REACH Annex XI, this study does not need to be conducted as testing is not technically possible. It is not possible to produce a powdered form of the substance suitable for testing as the powdered form is flammable.
It is not possible to generate an atmosphere of test material that would be suitable for testing. The smallest size of substance that can be generated without the risk of fire would be too dense to produce a test atmosphere for testing.
Furthermore, exposure of humans via inhalation will not occur as the substance is not used in powdered form and the powdered form of the substance will not be generated during substance use.

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: dermal

Data waiving:

study technically not feasible

Justification for data waiving:

the study does not need to be conducted because the physicochemical and toxicological properties suggest no potential for a significant rate of absorption through the skin

the study does not need to be conducted because the substance does not meet the criteria for classification as acute toxicity or STOT SE by the oral route and, in the absence of an in vivo study by the oral route, no systemic effects after dermal exposure are predicted on the basis of non-testing approaches (e.g. read across, QSAR studies)

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
In accordance with Section 2 of REACH Annex XI, this study does not need to be conducted as testing is not technically possible. It is not possible to produce a powdered form of the substance suitable for testing as the powdered form is flammable.
It is not considered appropriate to test an extract following dissolution of the massive form in aqueous media as the substance is highly insoluble meaning there would be an insufficient concentration of dissolved metal ions in the extract solution to be tested.
As the substance is highly insoluble, the study is also omitted on grounds there would be no potential for a significant rate of absorption through the skin.
Furthermore, information from an acute oral toxicity study conducted with the read across substance, samarium oxide, suggests the substance does not meet the criteria for classification as acute toxicity or STOT SE (acute oral LD50 > 5 000 mg/kg).
Since the surface of samarium metal oxidises on contact with air to form an outer layer of samarium oxide. It is therefore considered appropriate to read across information from samarium oxide to the metal where testing on the metal is not technically possible.

Reference 2

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

16 May 2012 to 30 May 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

The surface of samarium metal oxidises on contact with air to form an outer layer of samarium oxide. It is therefore considered appropriate to read across information from samarium oxide to the metal where testing on the metal is not technically possible.

Reason / purpose for cross-reference:

other: read-across target

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 7 weeks (males); 8 weeks (females)
- Weight at study initiation: 231 - 243 g (males), 196 - 216 g (females)
- Housing: Animals were housed individually in solid-bottomed clear polycarbonate cages with a stainless steel mesh lid.
- Diet: Ad libitum
- Water: Ad libitum
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 - 25 °C
- Humidity (%): 30 - 70 %
- Air changes (per hr): ca. 15 air changes per hour
- Photoperiod (hrs dark / hrs light): 12 hours dark/ 12 hours light

Type of coverage:

semiocclusive

Vehicle:

water

Remarks:

(distilled)

Details on dermal exposure:

TEST SITE
- Area of exposure: Approximately 24 hours before treatment, fur was removed from the dorsal area of the trunk of the test area by clipping.
- % coverage: at least 10 %
- Type of wrap if used: Test material applications were held in place under gauze dressings.

REMOVAL OF TEST SUBSTANCE
Following the 24 hour exposure period the gauze dressings were removed and the treated areas were rinsed with distilled water.

TEST MATERIAL
- Amount(s) applied: 1 g or 4 g of test material was weighed and 5 or 20 mL of distilled water was added. The preparation was magnetically stirred to obtain a white solution just before administration. The preparation was administered under a volume of 10 mL/kg bw.

Duration of exposure:

24 hours

Doses:

2 000 mg/kg bw

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: A check for mortality was conducted daily together with systematic examinations to identify any behavioural or toxic effects on the major physiological functions. Body weights were taken just before test material application (day 0) and again on days 2, 7 and 14.
- Necropsy of survivors performed: Yes

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

None of the animals died during the study.

Clinical signs:

other: No clinical signs that were related to treatment with the test material were observed.

Gross pathology:

No treatment-related effects were noted at necropsy.

Interpretation of results:

other: Not classified in accordance with EU criteria

Conclusions:

Under the conditions of the study the acute dermal LD50 to male and female Sprague Dawley rats was determined to be in excess of 2 000 mg/kg bw.

Executive summary:

The acute dermal toxicity of the test material was investigated in a study which was conducted in accordance with the standardised guidelines OECD 402 and EU Method B.3, under GLP conditions.

During the study a group of 5 male and 5 female Sprague Dawley rats were exposed to a single dermal application of test material at the limit dose of 2 000 mg/kg bw under semi-occlusive conditions for 24 hours after which the test material was removed with distilled water. The rats were observed for 14 days.

None of the animals died during the study, no clinical signs that could be related to treatment with the test material were noted and all animals gained weight during the study. The macroscopic examination of the animals at necropsy revealed no treatment-related effects.

Therefore, under the conditions of the study, the acute dermal LD50 to male and female Sprague Dawley rats was determined to be in excess of 2 000 mg/kg bw.

Reference 3

Endpoint:

acute toxicity: dermal

Type of information:

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

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study conducted on read-across material

Justification for type of information:

The surface of samarium metal oxidises on contact with air to form an outer layer of samarium oxide. It is therefore considered appropriate to read across information from samarium oxide to the metal where testing on the metal is not technically possible.

Reason / purpose for cross-reference:

read-across source

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Additional information

Acute Oral Toxicity

In accordance with Section 2 of REACH Annex XI, this study does not need to be conducted as testing is not technically possible. It is not possible to produce a powdered form of the substance suitable for testing as the powdered form is flammable.

It is not considered appropriate to test an extract following dissolution of the massive form in aqueous media as the substance is highly insoluble meaning there would be an insufficient concentration of dissolved metal ions in the extract solution to be tested.

- Supporting information on the read-across substance, samarium oxide

- 1990 Study:

The acute oral toxicity of the test material, samarium oxide, was investigated.

During the study, a Limit Dose of 5.0 g/kg was administered by gavage (50 % w/w solution in distilled water) to 10 fasted Sprague-Dawley rats (200-300 g) using 5/sex. Animals were observed for clinical signs for 14 days following dosing.

Under the conditions of the study the acute oral LD50 to male and female Sprague dawley rats was determined to be in excess of 5 000 mg/kg.

- 1963 Study:

The acute oral toxicity of the test material, samarium oxide, was investigated.

During the study, a single 1 000 mg/kg dose of test material was administered, as a 50 % aqueous solution, by gavage to a group of female rats. The rats were subsequently observed for a period of 30 days.

Under the conditions of the study the acute oral LD50 to female rats was determined to be in excess of 1 000 mg/kg.

Since the surface of samarium metal oxidises on contact with air to form an outer layer of samarium oxide, it is considered appropriate to read across information from samarium oxide to the metal where testing on the metal is not technically possible.

Acute Inhalation Toxicity

In accordance with Section 2 of REACH Annex XI, this study does not need to be conducted as testing is not technically possible. It is not possible to produce a powdered form of the substance suitable for testing as the powdered form is flammable.

It is not possible to generate an atmosphere of test material that would be suitable for testing. The smallest size of substance that can be generated without the risk of fire would be too dense to produce a test atmosphere for testing.

Furthermore, exposure of humans via inhalation will not occur as the substance is not used in powdered form and powdered form of the substance will not be generated during substance use.

Acute Dermal Toxicity

In accordance with Section 2 of REACH Annex XI, this study does not need to be conducted as testing is not technically possible. It is not possible to produce a powdered form of the substance suitable for testing as the powdered form is flammable.

It is not considered appropriate to test an extract following dissolution of the massive form in aqueous media as the substance is highly insoluble meaning there would be an insufficient concentration of dissolved metal ions in the extract solution to be tested.

As the substance is highly insoluble, the study is also omitted on grounds there would be no potential for a significant rate of absorption through the skin.

Furthermmore, information from an acute oral toxicity study conducted with the read across substance, samarium oxide, suggests the substance does not meet the criteria for classification as acute toxicity or STOT SE (acute oral LD50 > 5 000 mg/kg).

Since the surface of samarium metal oxidises on contact with air to form an outer layer of samarium oxide. It is therefore considered appropriate to read across information from samarium oxide to the metal where testing on the metal is not technically possible.

- Supporting information on the read-across substance, samarium oxide

The acute dermal toxicity of the test material was investigated in a study which was conducted in accordance with the standardised guidelines OECD 402 and EU Method B.3, under GLP conditions.

During the study a group of 5 male and 5 female Sprague Dawley rats were exposed to a single dermal application of test material at the limit dose of 2 000 mg/kg bw under semi-occlusive conditions for 24 hours after which the test material was removed with distilled water. The rats were observed for 14 days.

None of the animals died during the study, no clinical signs that could be related to treatment with the test material were noted and all animals gained weight during the study. The macroscopic examination of the animals at necropsy revealed no treatment-related effects.

Therefore, under the conditions of the study, the acute dermal LD50 to male and female Sprague Dawley rats was determined to be in excess of 2 000 mg/kg bw.

Justification for classification or non-classification

In accordance with the criteria for classification as defined in Annex I, Regulation (EC) No 1272/2008, the substance does not require classification with respect to acute toxicity via the oral or dermal routes.