IODINE (I₂)

SYNONYMS
None known.
GENERAL PRECAUTIONS
Use a fume hood.
Avoid skin and eye contact, vapou
r or solid.
Avoid inhalation of the vapour. Store in a tightly closed container.
Wash hands thoroughly after handling.
CHARACTERISTICS
Brittle plates or small crystals, greyish violet in colour, with a metallic sheen. Irritating odour.
HEALTH HAZARD DATA
A toxic and corrosive solid which attacks the central nervous system, the gastro­intestinal tract and can cause kidney damage. It can be absorbed through the skin in large enough doses to be toxic. Inhalation can cause corrosion of the respiratory tract. Over exposure to vapour can be fatal. Vapour exposure to the eyes causes severe irritation and burning. Skin contact causes localised burning and irritation. Inhalation causes severe irritation with coughing and wheezing. Ingestion can cause gastroenteritis, hypotension, delirium, collapse, stupor and death.
TREATMENTS
Skin ­ remove contaminated clothing and immediately wash the affected area with large amounts of water until all evidence of the chemical has been removed (approximately 15 minutes). If burning or irritation persist seek medical attention. Wash contaminated clothing before re­use.
Eyes ­ immediately wash the affected eye with large amounts of water until all evidence of the chemical has been removed (approximately 15 minutes). If burning or irritation persist seek medical attention.
Inhalation ­ remove from the area of exposure to fresh air. If breathing has ceased apply artificial respiration. Keep warm and allow to rest. Seek medical attention if necessary.
Ingestion ­ if the victim is conscious give promptly milk, starch, flour or eggs, then seek immediate medical advice.
INCOMPATIBILITY
Heating produces toxic fumes of iodine and iodine compounds. Iodine is incompatible with ­ acetylene, ammonia, alkaloids, starch, tannins and reducing agents.
STORAGE
Store in a tightly closed container in a cool, dry atmosphere away from heat or incompatible substances.
HANDLING
Use a fume hood to keep the level of exposure below the recommended threshold level, ie. 0.1ppm (NH & MRC, Australia). If exposure is expected to exceed this limit then a respirator is recommended. Wear protective clothing. A long sleeved laboratory coat or gown, rubber gloves, safety goggles and a face mask as a minimum standard.
DISPOSAL
WEAR:
Rubber gloves, face shield and laboratory coat. A body shield should be available for the more active agents. Replace the face shield with self contained breathing apparatus for such agents as chlorine and bromine.
SPILLS:
Gas leak: if the valve is leaking because it cannot be closed, the gas can be bubbled through a reducer (sodium sulphite) and excess sodium bicarbonate solution. Be sure to include a trap in the line to prevent the solution being sucked back into the cylinder. If this cannot be done the cylinder should be placed in or adjacent to a fume hood and left to bleed off. If the leak is in the valve assembly, a plastic bag can be fastened over the head of the cylinder which can then be taken outside or to a fume hood.
Liquid or solid: cover with a reducer (sodium thiosulphate, a bisulphite or a ferrous salt not carbon, sulphur or strong reducing agent). Mix well and spray with water. A sulphite or a ferrous salt will require addition of 3mol/l sulphuric acid to promote a rapid reduction. Scoop the slurry into a container of water and neutralise with soda ash. Discharge to sewer with a large excess of water. Wash the site thoroughly with a soap solution containing some reducer.
PACKAGE LOTS:
Add to a large volume of concentrated solution of reducer (sodium thiosulphate, a bisulphite or a ferrous salt and acidify with 3mol/l sulphuric acid). When the reduction is completed add soda ash or dilute hydrochloric acid to neutralise the solution. Discharge to sewer with a large excess of water.
ENVIRONMENT:

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