Intro to Chlorine Dioxide
Chlorine dioxide is a chemical compound with the formula CIO2, meaning its molecule has one atom of chlorine and two atoms of oxygen. In an industrial setting, its typically handled as an aqueous solution and appears a rusty red liquid when below 11°C (52°F). Its most common uses are antimicrobial and oxidizing agents in drinking water, poultry process water, swimming pools, and mouthwash preparations. Other uses include bleaching wood pulp, food processing - fats, oil, and flour, and sterilizing medical equipment. When comparing to chlorine gas, chlorine dioxide has a higher oxidation capacity and a lower oxidation strength—making it over 2.5 times more potent per ppm and significantly less corrosive.
While CIO2 is a hazardous gas, the risk to industrial workers isn't typically in this form since it rapidly breaks down into chlorine gas and oxygen. In the case of an exposure, short-term symptoms are typically irritation of the eyes, nose, throat, and lungs. Coughing, wheezing, and severe breathing difficulties can develop at any exposure limit. Longer-term exposure can often result in chronic bronchitis.
Gas Characteristics
- Penetrating and irritating odor (similar to chlorine and nitric acid).
- Gas: yellowish- green gas at room temperature.
- Liquid: reddish-brown between 11 and -59°C.
- Solid: orange in color like a block of ice, with a faint chlorine odor.
- As an oxidizer, may cause or intensify a fire.
- Gas is heavier than air.
- Signal word: Danger.
- Toxic if inhaled.
- Other names: Chlorine oxide, Chlorine peroxide.
- CAS 10049-04-4
FIRST AID
- Ensure anyone conducting first aid is adequately protected (safety goggles & chemical protective clothing).
- If INHALED move the person to fresh air right away. If breathing has stopped begin artificial respiration. Keep the victim still and upright if possible. Trained personnel can administer additional oxygen if necessary. Get medical attention as soon as possible.
- If SKIN CONTACT is made rinse the impacted area with soap and water immediately. See a doctor if the pain/irritation does not subside.
- If the EYES are contacted, immediately wash the eyes with large amounts of water. Next cover both eyes with sterile gauze to minimize light. Get medical attention immediately.
IF ACCIDENTALLY RELEASED
- Evacuate the area ASAP, and keep out any personnel who are not wearing protective equipment.
- Isolate the area that is concentrated with chlorine dioxide.
- If you have the necessary protection to do so, attempt to remove any incompatible/hazardous materials that could escalate the situation.
- If the gas is leaked, stop the flow if it can be done safely. If the source is in a cylinder remove it to open air. To stop the leak in place, bubble chlorine dioxide through a solution made from a reducing agent like sodium bisulfite and sodium bicarbonate with a trap in the line. Try to ventilate the area.
- If the leak is larger, follow the same steps as for a small leak. However, you can also consider knocking down the gas with fine water spray or fog. If the leak cannot be contained, contact local emergency services.
- Potential contamination in water systems should be communicated to downstream users.