Lithium benzoate

Endpoint summary

Description of key information

Assessment has been made based on the well established toxicity profile of benzoate (specifically sodium benzoate) and lithium salts.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

500 mg/kg bw

Quality of whole database:

Extensive reviews by national and international regulatory agencies on lithium and benzoate salts.

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

2 000 mg/kg bw

Additional information

There are limited data relating to dermal absorption of lithium and benzoate ions.

 

Certain lithium salts are corrosive or irritating to skin and dermal toxicity data from such salts are not considered valid for assessment; lithium carbonate is of low irritation and is the main salt for therapeutic use. Acute dermal toxicity results are reports from different sources to be > 2000 mg/kg and the carbonate is not classified.

 

Benzoic acid and sodium benzoate have also been assessed for acute dermal toxicity and these are not considered hazardous and are not classified.

 

One source of data is in the opinion of the scientific committee on cosmetic products and non-food products intended for consumers (European Commission 2002). This review is based on a number of primary sources of data and is considered sufficient to confirm that these salts are of low dermal toxicity.

 

No further animal testing can be justified.

Reviews have been found, published by:

 

World Health Organisation, International Programme on Chemical Safety (IPCS)

http://www.inchem.org/documents/cicads/cicads/cicad26.htm

 

Scientific Committee On Consumer Products, Opinion on Benzoic Acid and Sodium Benzoate, 2005

http://ec.europa.eu/health/ph_risk/committees/04_sccp/docs/sccp_o_015.pdf

 

SIDS INITIAL ASSESSMENT PROFILE: Benzoates, 2001

http://www.chemicals.moew.government.bg/chemical/site/File/registers/profile/BENZOATESp.pdf

http://www.inchem.org/documents/sids/sids/BENZOATES.pdf

  

Benzyl Alcohol, Benzoic Acid, and its Salts and Ester,  CIR Expert Panel Meeting 2011

http://www.cir-safety.org/sites/default/files/119_draft_benzyl.pdf

Justification for classification or non-classification

Lithium carbonate, sodium benzoate and benzoic acid have all been extensively reviewed by national and international agencies. Lithium carbonate is the most commonly used form of lithium for medicinal use, in view of good water solubility and low irritancy; some data on organic salts are available and these have been used when appropriate to enhance this assessment.

Clinical signs of intoxication (for benzoates in rats) included diarrhoea, muscular weakness, tremors, hypoactivity and emaciation. No clinical signs of over exposure in humans has been reported.

The US FDA suggest lithium overdose in humans may lead to diarrhoea, vomiting, drowsiness, muscular weakness and lack of coordination.

The LD50 is estimated on the basis that lithium is likely to be the more toxic ion

Using reported oral LD50 for lithium carbonate (500 - 700 mg/kg), the estimated LD50 for lithium element is 50 - 70 mg/kg in rats.

Extrapolating to lithium benzoate suggests that with the presence of approximately 5% by weight lithium, the toxicity of lithium benzoate is estimated 1000 - 1400 mg/kg

No further animal testing is justified and the substance should be classified as Acute Tox 4