ABC of Safety in the Biological Sciences
POTASSIUM NITRATE (KNO3)
Avoid eye contact.
Keep away from heat.
Wash hands thoroughly after handling.
Colourless crystals or a white crystalline powder.
HEALTH HAZARD DATA
A strong oxidising agent which is moderately toxic by ingestion and an eye irritant. There is insufficient data available on the health hazards associated with the handling of and exposure to this chemical.
Skin immediately wash the affected area with large amounts of water until all evidence of the chemical has been removed (approximately 15 minutes). Seek medical advice if necessary.
Eyes immediately wash the affected eye with large amounts of water until all evidence of the chemical has been removed (approximately 15 minutes). If irritation persists seek immediate medical attention.
Inhalation remove from the area of exposure to fresh air. If breathing has ceased apply artificial respiration. Seek medical advice if necessary.
Ingestion wash the mouth with water and give two to four glasses of water to drink. Induce vomiting by touching a finger to the back of the throat. Seek immediate medical attention. Never give anything by mouth to a patient that is not conscious.
Store in a cool, dry atmosphere away from heat.
Wear protective clothing to avoid eye contact. A minimum standard should be a long sleeved laboratory coat, rubber gloves, and safety goggles.
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.
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.
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.