Lithium hydroxide

Endpoint summary

Description of key information

Acute toxicity data are available for two routes of exposure: LD50 (rat, oral): female: 210 mg/kg bw; male: 280 mg/kg bw , both for lithium hydroxide anhydrous LD50 (mouse, oral): 363 mg/kg bw, for lithium hydroxide anhydrous As these values are most likely linked to local tissue damage due to the corrosiveness of the substance and are not only a result of "primary" systemic toxicity the LD50 oral of lithium chloride and lithium carbonate were taken into account after conversion. A LD50 value of 330 mg/kg bw and of 578 mg/kg bw were found to reflect properly the systemic toxicity of the corrosive substances lithium hydroxide anhydrous and lithium hydroxide monohydrate, respectively.  LC50 (rat, inhalation): > 6.15 mg/L air (analytical) for lithium hydroxide monohydrate; > 3.4 mg/L air calculated for lithium hydroxide anhydrous In accordance with column 2 of REACH Regulation 1907/2006/EC Annex VII section 8.5.3 an acute dermal toxicity study does not need to be conducted if the available information indicates that the criteria are met for classification as corrosive. Both substances, lithium hydroxide and lithium hydroxide monohydrate, are found to be corrosive. However, based on the data of other lithium salts like lithium chloride or lithium carbonate a dermal LD50 > 2000 mg/kg bw can be deduced.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1999

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Only data from review article available

Qualifier:

no guideline followed

Principles of method if other than guideline:

Only data from review article available. No guideline or method indicated.

GLP compliance:

not specified

Species:

mouse

Sex:

not specified

Dose descriptor:

LD50

Effect level:

363 mg/kg bw

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

According to the handbook-data, the LD50 of lithium hydroxide is 336.0 +/- 7.8 mg/kg bw after oral administration to mice.

Executive summary:

According to the handbook-data, the LD50 of lithium hydroxide is 336.0 +/- 7.8 mg/kg bw after oral administration to mice.

Reference 2

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1999

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Only data from review article available

Qualifier:

no guideline followed

Principles of method if other than guideline:

Only data from review article available. No guideline or method indicated.

GLP compliance:

not specified

Species:

rat

Sex:

male/female

Sex:

female

Dose descriptor:

LD50

Effect level:

210 mg/kg bw

Sex:

male

Dose descriptor:

LD50

Effect level:

280 mg/kg bw

Sex:

female

Dose descriptor:

LD50

Effect level:

368 mg/kg bw

Remarks on result:

other: calculated for LiOH*H2O

Sex:

male

Dose descriptor:

LD50

Effect level:

491 mg/kg bw

Remarks on result:

other: calculated for LiOH*H2O

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

According to the handbook-data, the LD50 of lithium hydroxide is 210 +/- 21.5 mg/kg bw after oral administration to female rats and 280 +/- 34.4 mg/kg bw for male rats.

Executive summary:

According to the handbook-data, the LD50 of lithium hydroxide is 210 +/- 21.5 mg/kg bw after oral administration to female rats and 280 +/- 34.4 mg/kg bw for male rats. Based on these hand-book data, the LD50 values in rats for lithium hydroxide monohydrate are calculated to be 368 mg/kg bw after oral administration to female rats and 491 mg/kg bw for male rats. As the LD50 values of lithium hydroxide anhydrous are most likely linked to local tissue damage due to the corrosiveness of the substance and not a result of "primary" systemic toxicity, a higher LD50 is to be assumed.

Reference 3

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

no guideline followed

Principles of method if other than guideline:

Only handbook data available.

GLP compliance:

not specified

Species:

rat

Sex:

not specified

Dose descriptor:

LD50

Effect level:

526 mg/kg bw

Based on:

test mat.

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

According to the review article, the LD50 of lithium chloride is 526 mg/kg bw after oral administration to rats.

Executive summary:

According to the review article, the LD50 of lithium chloride is 526 mg/kg bw after oral administration to rats.

Reference 4

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1973

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Only data from review article available.

Reason / purpose for cross-reference:

reference to other study

Principles of method if other than guideline:

Only data from review article available. No guideline or method indicated.

GLP compliance:

not specified

Species:

rat

Key result

Sex:

not specified

Dose descriptor:

LD50

Effect level:

525 mg/kg bw

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

According to the review article, the LD50 of lithium carbonate is 525 mg/kg bw after oral administration to rats.

Executive summary:

According to the review article, the LD50 of lithium carbonate is 525 mg/kg bw after oral administration to rats.

Reference 5

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

no guideline followed

Principles of method if other than guideline:

Only handbook data available.

GLP compliance:

not specified

Key result

Sex:

male

Dose descriptor:

LD50

Effect level:

640 mg/kg bw

Based on:

test mat.

95% CL:

ca. 610 - <= 670

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

723 mg/kg bw

Based on:

test mat.

95% CL:

ca. 685 - <= 761

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

According to the handbook-data, the LD50 of lithium carbonate is 723 +/- 38 mg/kg bw after oral administration to female rats and 640 +/- 30 mg/kg bw to male rats.

Executive summary:

According to the handbook-data, the LD50 of lithium carbonate is 723 +/- 38 mg/kg bw after oral administration to female rats and 640 +/- 30 mg/kg bw to male rats.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

330 mg/kg bw

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1999-04-12 to 1999-08-20

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1300 (Acute inhalation toxicity)

Version / remarks:

August 1998

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Version / remarks:

May 1981

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.2 (Acute Toxicity (Inhalation))

Version / remarks:

December 1992

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River laboratories;
- Age at study initiation: young adult animals;
- Weight at study initiation: 200 - 300 g/animal prior to exposure
- Fasting period before study: None
- Housing: Individually, in suspended stainless steel cages with wire mesh bottoms.
- Diet: Purina laboratory Rodent Chow 5001 (pellets) ad lib.;
- Water: Domestic water supply; untreated with additional chlorine or HCl; ad lib.;
- Acclimation period: Minimum of five calendar days;


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 23.9 °C ;
- Humidity (%): 30 - 70 %;
- Air changes (per hr):Not stated;
- Photoperiod (hrs dark / hrs light): 12 hrs light/dark cycle; from 6:00 a.m. to 6:00 p.m.

Route of administration:

inhalation: dust

Type of inhalation exposure:

nose only

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: ADG nose-only exposure chamber;
- Exposure chamber volume: 11 L;
- Method of holding animals in test chamber: Individual polycarbonate nose-only tubes;
- Source and rate of air: Breathing grade compressed air; 39.1 L/min;
- Method of conditioning air: BGI Wright Dust Feeder II;
- System of generating particulates/aerosols: Compressed air dispersing the material into the exposure chamber;
- Method of particle size determination: Samples were drawn through a Sierra Series 218 cascade impactor;
- Treatment of exhaust air: Passing through an orifice tube system which continuously monitors air flow, then a commercial filter box;
- Temperature, humidity, pressure in air chamber: 20 °C; 35 % humidity;


TEST ATMOSPHERE
- Brief description of analytical method used: Sampling on Gelman Type A/E 37 mm glass fiber filters hold in cassettes.
- Samples taken from breathing zone: Centre of the chamber; directly above animal tube portals;

TEST ATMOSPHERE:
- Particle size distribution:
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): MMAD:4.68 - 4.69 µm; GSD: 2.7 to 2.74;


CLASS METHOD:
- Rationale for the selection of the starting concentration: To determine the inhalation LC50 value of the test material or to establish a non-lethal dosage level which is equal or greater than 5 mg/L or maximum attainable;

Analytical verification of test atmosphere concentrations:

yes

Remarks:

sampling on glass fiber filters; dividing filter weight gain by sample volume;

Duration of exposure:

4 h

Concentrations:

Nominal concentration. 12.7 mg/L;
Chamber airflow: 39.1 L/min;
Gravimetric concentration: 6.15 mg/L (mean)

No. of animals per sex per dose:

5 male; 5 female;

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: observation: daily; weighing: on day 0, 7, and 14 after exposure;
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, necropsy findings;

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 6.15 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 3.4 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: calculated for LiOH anhydrous

Mortality:

As a result of the exposure, two animals had severe necrosis of the snout. The severity of necrosis caused respiratory difficulties for these animals. On Study Day 5, these animals were deemed to be in moribund condition and were humanely sacrificed.

Clinical signs:

other: Treatment-related clinical signs observed during the study included abdominogenital staining, alopecia on head/neck, ataxia, chromodacryorrhea, chromorhinorrhea, decreased feces, decreased locomotion, diarrhea, dyspnea, lacrimation, necrotic snout, oral d

Body weight:

Four surviving females and two males lost weight during the day 0 through day 7 weighing interval. These same animals gained weight during the day 7 through day 14 weighing interval. The remaining male animals exhibited normal increases in body weight throughout the study.

Gross pathology:

There were no gross internal lesions observed in any animal at necropsy.

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of this study, the four-hour LC50 for lithium hydroxide monohydrate is greater than 6.15 mg/L (resp. greater than 3.4 mg/L lithium hydroxide anhydrous).

Executive summary:

The acute inhalation toxicity of lithium hydroxide monohydrate in Sprague-Dawley rats was determined according to OECD Guideline 403 and EU method B.2. A group of five male and five female Sprague-Dawley rats was exposed to a respirable aerosol of lithium hydroxide monohydrate. The animals were exposed for 4 hours at a mean concentration of 6.15 mg/L in a dynamically operated, nose-only inhalation exposure chamber. Gravimetric airborne test material samples were taken frequently during the exposure. Particle size samples were taken twice during the exposure. Observations for toxicity and mortality were performed frequently during the exposure, upon removal of the rats from the chamber, at one hour post-exposure and daily thereafter for 14 days. Individual body weights were recorded immediately prior to exposure on day 0 and on days 7, 14 and on day of unscheduled sacrifice. On day 14, all surviving animals were sacrificed and gross necropsy examinations were performed. Gross necropsies were also performed on animals that were humanely sacrificed. As a result of the exposure, two animals had severe necrosis of the snout. The severity of the necrosis caused respiratory difficulties for these animals. On Study Day 5, these animals were deemed to be in moribund condition and were humanely sacrificed. Treatment-related clinical signs observed during the study included abdominogenital staining, alopecia on head/neck, ataxia, chromodacryorrhea, chromorhinorrhea, decreased feces, decreased locomotion, diarrhea, dyspnea, lacrimation, necrotic snout, oral discharge, rales, squinting eyes, swollen snout, and unthriftiness. Other signs included unkempt fur and wet material on fur. All surviving animals were normal from day 11 through study termination. Four surviving females and two males lost weight during the day 0 through day 7 weighing interval. These same animals gained weight during the day 7 through day 14 weighing interval. The remaining male animals exhibited normal increases in body weight throughout the study. There were no gross internal lesions observed in any animal at necropsy. Under the conditions of this study, the four-hour LC50 for Lithium hydroxide monohydrate is greater than 6.15 mg/L (resp. greater than 3.4 mg/L lithium hydroxide anhydrous).

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LC50

Value:

3 400 mg/m³ air

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:

1993-10-01 to 1994-04-01

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Version / remarks:

1987

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

1987

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPP 81-2 (Acute Dermal Toxicity)

Version / remarks:

1984

Deviations:

no

GLP compliance:

yes

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
- Source: Charles River Laboratories
- Age at study initiation: Young adult
- Weight at study initiation: male: 261 g ± 4.1 g; female: 234 g ± 7.4 g
- Housing: individually housed in stainless steel suspended rat cages, wire bottom
- Diet (e.g. ad libitum): ad libitum, Purina Rodent Chow 5001 (pellets)
- Water (e.g. ad libitum): ad libitum, fresh tap water
- Acclimation period: The animals were acclimated for a minimum of 5 calendar days prior to study start.


ENVIRONMENTAL CONDITIONS
- Temperature (degree C): 19 - 22.8 degree C
- Humidity (%): 40 % - 69 %
- Photoperiod (hrs dark / hrs light): 12 hours fluorescent/ 12 hours dark

Type of coverage:

occlusive

Vehicle:

physiological saline

Details on dermal exposure:

TEST SITE
- Area of exposure: intact test site
- Type of wrap if used: The gauze was positioned on the intact test site and held place with hypoallergenic tape. The test site was then covered with an elastic bandage which was lined with plastic.


REMOVAL OF TEST SUBSTANCE
- Washing (if done): The test sites were wiped with clean gauze moistened with methanol, then rinsed with tap water.
- Time after start of exposure: 24 hours

Duration of exposure:

24 hours

Doses:

Doses corresponding to a dosage level of 2000 mg/kg were individually calculated based on the body weight of each animal on the day of dosing.

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: Observations for mortality and clinical signs (local irritation excluded): 0.5, 1, 2, 3, 4 and 6 hours on the day of dosing and twice daily thereafter for 13 days; on day 14 the animals were observed once description of the local irritation was recorded on days 1, 3, 7 and 14 of the study, body weights: on days 0, 7 and 14
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, local irritation, body weight, necropsy

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

There were no deaths.

Clinical signs:

other: All rats remained healthy during the study.

Gross pathology:

There were no gross internal lesions observed in any animals at necropsy.

Mean Body Weights ± SD

	Day 0	Day 7	Day 14
Male	261 ± 4.1	312 ± 3.4	350 ± 5.4
Female	234 ± 7.4	254 ± 7.0	264 ± 7.2

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of this study, the LD50 is greater than 2000 mg/kg in male and female rats when topically applied.

Executive summary:

In accordance with column 2 of REACH Regulation 1907/2006/EC Annex VII section 8.5.3 an acute dermal toxicity study does not need to be conducted if the available information indicates that the criteria are met for classification as corrosive. Both substances, lithium hydroxide and lithium hydroxide monohydrate, are found to be corrosive and a dermal acute toxicity study with the substances as such would not generate meaningful values because of local tissue damage due to corrosiveness. Thus, this study is not required. However, in case of non-corrosive solutions no acute dermal toxicity is expected for lithium hydroxide anhydrous and lithium hydroxide monohydrate. Similar to other lithium salts the acute dermal toxicity is expected to be LD50 is > 2000 mg/kg bw as noted for of e.g. lithium carbonate, reflecting the almost negligible skin penetration of inorganic salts. For this reason, instead of studies with lithium hydroxide and lithium hydroxide monohydrate, the dermal acute toxicity study with lithium carbonate is summarised in the following: The toxic effects of lithium carbonate in Sprague-Dawley rats were investigated according to OECD Guideline 402 and EU method B.3 on acute dermal toxicity. Ten Sprague-Dawley rats (5 males and 5 females) were treated with lithium carbonate Pharmaceutical Grade (Typical Wt% = 99.7; Guaranteed Wt% = 99) at a dosage level of 2000 mg/kg. The test material was in contact with the intact skin for 24 hours under an occlusive wrap. Observations for toxicity were conducted at 0.5, 1, 2, 3, 4 and 6 hours on the day of dosing and twice daily thereafter for 13 days; on day 14 they were conducted once. A description of local irritation was recorded on day 1, 3, 7 and 14. Body weights were recorded on days 0, 7 and 14 of the study. A gross necropsy was performed on all animals. There were no deaths. All rats remained healthy and gained weight by day 14 of the study. No irritations was noted on any of the test sites. All animals appeared normal at necropsy. Under the conditions of this study, the LD50 is greater than 2000 mg/kg in male and female rats when topically applied.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Additional information

Acute oral toxicity

According to the handbook-data, the LD50 oral of lithium hydroxide anhydrous is ca. 210 to 330 mg/kg bw in rat and mouse. Further a study with lithium hydroxide monohydrate was conducted revealing a LD50 value of 197.7 mg/kg bw /day (reliability 3). All LD50 values are most likely linked to local tissue damage due to the corrosiveness of the substance and not only a result of "primary" systemic toxicity. Consequently, the acute toxicity noted represents a sum of local and (primary and secondary) systemic effects.

For lithium salts, significantly higher LD50 (oral) values of ca. 500 -700 mg/kg bw/day are reported.

After conversion of the LD50 values of lithium carbonate and lithium chloride, the LD50 oral values are calculated to be for

- Lithium hydroxide anhydrous: ca. 340 - 526 mg/kg bw and

- Lithium hydroxide monohydrate: ca. 596 - 921 mg/kg bw.

This supports properly the conclusion, that 330 mg/kg bw and 578 mg/kg bw reflect properly the systemic toxicity of the corrosive substances lithium hydroxide anhydrous and lithium hydroxide monohydrate, respectively.

For risk characterisation, acute DNEL (oral route) was not assessed from the presented animal data but was derived from the long-term DNEL (oral route) which was based on human data (see IUCLID section 7: toxicological information).

Acute inhalation toxicity

In an acute inhalation study the LC50 was found to be greater than 6.15 mg/L for lithium hydroxide monohydrate (resp. greater than 3.4 mg/L for lithium hydroxide anhydrous).

For risk characterisation, acute DNEL (inhalation route) was not assessed from the presented animal data but was derived from the long-term DNEL (oral route) which was based on human data (see section 7: toxicological information).

Acute dermal toxicity

In accordance with column 2 of REACH Regulation 1907/2006/EC Annex VII section 8.5.3 an acute dermal toxicity study does not need to be conducted if the available information indicates that the criteria are met for classification as corrosive. Both substances, lithium hydroxide and lithium hydroxide monohydrate, are found to be corrosive. Thus, this study is not required.

However, a study on acute dermal toxicity has been conducted in 1976 with lithium hydroxide anhydrous. Four male and four female New Zealand white rabbits were treated (a 24 -hour occlusive dermal application) with an lithium hydroxide monohydrate aqueous slurry at dose levels of 200 mg/kg bw and 3000 mg/kg bw. No mortality occurred at the 200 mg/ kg bw dose group but 4/4 animals died at 3000 mg/kg bw dose group. The test material was extremely corrosive to the skin and subcutaneous tissues of the albino rabbits. Skin changes at 24 hours were characterized by total destruction of the skin and partial destruction of the skeletal muscle tissue. In addition, extreme haemorrhaging was noted at the exposure sites with large amounts of free blood under the occlusive sleeves. Necrosis was observed at the exposure sites of the 200 mg/kg animals at 7 and 14 days. Due to the limited number of dose groups together with the wide spacing between the selected concentrations (200 and 3000 mg/kg bw) and the obtained results, no classification and labelling could be determined based on the study results regarding acute dermal toxicity.

Nevertheless, results showed that the test substance is corrosive. However, in case of non-corrosive solutions no acute dermal toxicity is expected for lithium hydroxide anhydrous and lithium hydroxide monohydrate. Similar to other lithium salts the acute dermal toxicity is expected to be LD50 > 2000 mg/kg bw as noted for e.g. lithium carbonate, reflecting the almost negligible skin penetration of inorganic salts. Remark on key values acute toxicity for chemical safety assessment: Acute toxicity DNEL was derived from animal data noted for lithium chloride and lithium carbonate.

Justification for classification or non-classification

Acute oral toxicity

Based on a weight of evidence approach a LD50 of ≥ 330 mg lithium hydroxide anhydrous /kg bw and LD50 of ≥ 578 mg lithium hydroxide monohydrate /kg bw properly reflect the systemic toxicity of these corrosive substances

Thus, both substances have to be classified as Category 4 (H302) according to Regulation (EC) No 1272/2008 (CLP).

Acute inhalation toxicity

In an acute inhalation study the LC50 was found to be greater than 6.15 mg/L for lithium hydroxide monohydrate (resp. greater than 3.4 mg/L for lithium hydroxide anhydrous). Based on this data, lithium hydroxide monohydrate and lithium hydroxide anhydrous are not liable for classification and labelling for inhalation toxicity according to Regulation (EC) No 1272/2008 (CLP).

Acute dermal toxicity

In accordance with column 2 of REACH Regulation 1907/2006/EC Annex VII section 8.5.3 an acute dermal toxicity study does not need to be conducted if the available information indicates that the criteria are met for classification as corrosive. Both substances, lithium hydroxide and lithium hydroxide monohydrate, are found to be corrosive. Thus, this study is not required. However, in case of non-corrosive solutions no acute dermal toxicity is expected for lithium hydroxide anhydrous and lithium hydroxide monohydrate. Similar to other lithium salts the acute dermal toxicity is expected to be LD50 is > 2000 mg/kg bw as noted for e.g. lithium carbonate, reflecting the almost negligible skin penetration of inorganic salts. Consequently, the substances are not to be classified with respect to acute dermal toxicity according to Regulation (EC) No 1272/2008 (CLP).