Contact with excessive amounts of MDI vapor, liquid or aerosol can be harmful to your health. There are four possible ways you may become overexposed:

• breathing high airborne concentrations
• getting it in your eyes
• getting it on your skin
• swallowing it

Here are the effects of overexposure and some recommended first-aid:

Inhalation: If MDI is sprayed as a mist or heated, or handled where there is poor ventilation, there is a greater chance of overexposure. Even if you cannot smell MDI, you may be in danger of overexposure, because most people cannot smell MDI until concentrations are well above allowable limits. MDI can irritate your nose and lungs. You may feel tightness in your chest and have difficulty breathing. Overexposure may cause you to become sensitized or “allergic” to MDI which will cause you to have asthma-like attacks if you breathe MDI vapors again. If this happens, any further exposure must be avoided. Effects may occur immediately upon exposure, or be delayed for several hours after exposure ends.

If you suspect someone has become overexposed, remove the person to an area with fresh air, and try to keep them calm and warm — but not hot. Call a physician at once. If they are having difficulty breathing, a qualified person may provide oxygen. If they stop breathing, give artificial resuscitation. Call a doctor at once.

Eye Contact: Getting MDI in your eyes can be painful and could cause tearing and irritation. If you get MDI in your eyes, wash them immediately with a continuous flow of low pressure water, preferably from an eyewash fountain, for at least 15 minutes. See a doctor at once.

Skin Contact: Getting MDI on your skin may play a role in sensitization. Animal tests have indicated that respiratory sensitization may occur from skin contact with MDI. Repeatedly getting MDI on your skin may also cause discoloration, redness, swelling, blistering, or burns. It is best to conduct your work to avoid skin contact, but if you get MDI on your skin, wash thoroughly with soap and flowing water (warm water if available).

If your skin is irritated or burned, seek medical attention. Any clothing contaminated with MDI must be removed and small amounts can be decontaminated by soaking them in an 8% ammonia solution for one hour before washing with detergent and hot water. Leather items cannot be decontaminated. Any contaminated leather items, including shoes, belts, and watchbands or clothing which has been exposed to large amounts of MDI, should be properly discarded.

Ingestion: Swallowing MDI can cause irritation, burns or sores in your mouth, throat and stomach. If you swallow MDI, drink two to three glasses of water or milk. Do not try to vomit. See a physician immediately.

With proper precautions, you can use MDI safely by protecting yourself from overexposure. Where there is adequate ventilation and potential for overexposure to MDI liquid or vapor is minimal, you should use:

• Safety glasses or chemical worker’s goggles
• MDI-resistant chemical gloves
• Long-sleeve coveralls (Heavy cotton preferred)
• Safety shoes or boots

Where there is a risk of exposure to MDI liquid or vapor above allowable exposure limits, you should use:

• An approved respirator, either air-supplied or air-purifying (consult your company safety professional or the product MSDS for guidance)
• Chemical worker’s goggles
• MDI-resistant long-sleeve coveralls or full body suit
• MDI-resistant fitted boots and
• Head protection, such as a close-fitting hood

MDI is a very reactive chemical. Reactions with buildup of heat or pressure can result from improper mixing with:

• Acids, inorganic bases (such as sodium hydroxide), ammonia, and amines;
• Magnesium, aluminum and their alloys
• Other metal salts, especially halides (such as tin, iron, aluminum and zinc chlorides)
• All strong oxidizing agents (such as bleach or chlorine)
• Polyols
• Water

Caution: Resealing MDI containers contaminated with any of the above materials can cause a buildup of pressure in the container and cause it to explode. All forms of MDI can also self-react in a fire or at very high temperatures, releasing carbon dioxide and causing the buildup of pressure in sealed containers sufficient to cause explosion.

To minimize hazards when handling, unloading, or storing MDI:

• Wear protective clothing
• Follow established procedures for normal operations (Take special care to minimize hazards when transferring MDI from one container to another.), emergencies, maintenance, loading/ unloading, sampling and special operations
• Use appropriate checklists for specific procedures
• Inspect equipment to ensure operating integrity following maintenance procedures
• Maintain good housekeeping
• Participate in company-sponsored training programs

Handling Drums:

• Wear protective clothing
• Follow all safety precautions for handling MDI until empty drums are decontaminated
• Handle and store drums in a well-ventilated area with containment
• Check drum shipments for leakage
• Do not strike drums and bungs with tools which may cause sparking
• Never use pressure to empty drums
• Do not store MDI in open-head drums
• Use plugs/caps on terminal valves or fittings and bleed valves
• Keep drum overpacks available
• Do not stack palletized drums more than three high
• Never cut empty MDI drums with a torch
• Never remove empty MDI drums from a worksite for personal use

Fires, spills and other emergencies involving MDI require immediate responses by trained, knowledgeable personnel. If you are not a trained, designated emergency responder, leave the area immediately and notify the appropriate emergency response personnel.

If the spill involves a tank car or tank truck, or you need additional guidance, call CHEMTREC® at 1-800-424-9300.

CHEMTREC® operators are available 24 hours a day, seven days a week.