Potassium iodide

Endpoint summary

Description of key information

Skin irritation/corrosive: With existing evidence, it can be concluded that iodide has no effect to the human skin.Eye irritation/corrosive: Although there is some exceptional case showing the iodide can have different degrees of impact on eyes, most reports gave negative results. 

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Additional information

Iodine has been used for dermal application in human as disinfectant (as Iodine and Povidine Iodine) for long time. The mechanism of disinfecting is oxidizing bactericide by iodine; meanwhile the iodine is reduced to iodide. It means after application of iodine on skin, the iodide is left on skin. In addition, based on information from assessment report of WHO, in a human assay, five patients were applied with potassium iodide in concentrations ranging from 5% to 20% in petrolatum, the reactions were negative. With such evidence, it can be concluded that iodide has no effect to the human skin.

 

Van Ketel and van den Berg (1990) described eight patients who had skin reactions from topical administration of povidone-iodine (5% or 10% in petrolatum or Betadine solution, ointment, or scrub) and patchtested positively to these applications. In five of eight patients also tested with potassium iodide in concentrations ranging from 5% to 20% in petrolatum, the reactions were negative.

Old Testing of potassium iodide on rabbit eyes by injection of 3% solution into the comea has caused only slight reaction, graded 17 on a scale of 0 to 100. However this score currently can not be considered as irritation because 17/100 evidently below 1/4 of tody’s criteria.

A series of 5,000 intravenous injection has been given to patients in treatment of eye diseases without causing any perceptible disturbance of the visual apparatus.

In individuals hypersensitive to iodidea stateofiodismmay be precipitated by small doses, and some the lids and conjunctivae are involved. In this condition there is a watery rhinitis, lacrimation, edema of the eyelids, and conjunctival hyperemia.

Rarely superimposed infection may cause more serious disturbances, and in one instance hypopyon was observed in the anterior chambers. Serious involvement of the eyes in iodism is uncommon, but in two patients severe keratoconjunctivitis has been reported and in one of these there were hemorrhagic iritis and vitreous opacities. The eyes recovered when iodides were discontinued. The ordinary signs and symptoms of iodism clear up promptly when iodides are stopped.

However by these special cases it can not be concluded that the iodide can induce eye irritation to human.

It is occasionally reported that an exacerbation of exophthalmos shortly after very small doses of iodides by mouth. In addition a rare instance of severe reaction to iodide has been reported in a case of syphilitic osteoperiostitis of the orbit resulting in acute orbital edema and exophthalmos, leading to bilateral optic atrophy. However, these are all special cases to patients or uncommonly cases which are not statistically significant.

In treatment of glaucoma, as in treatment of many other diseases, iodides long ago were tried systemically and found to have neither adverse nor clearly beneficial effect. Experimental studies of physiologic rather than toxicological interest have shown iodide to be transported out of the aqueous humor by the ciliary body in rabbits. Sodium iodide injected into the vitreous in rabbits is reported not to have altered the ERG. However this data is not related to eye irritation.

Therefore no irritation to eyes can be concluded for iodide.

Justification for classification or non-classification

Based on existing information, iodide does not meet the skin or eyes irritation/corrosion criteria under the Regulation (EC) No. 1272/2008 nor Directive 67/548/EEC.