8. Emergency Procedures

Guidelines for Dealing with TDI Product Incidents

All incidents tend to be unique, and it is not possible to write guidelines to deal with every circumstance. Each incident must be assessed from the information available.

All people involved with handling or transportation of TDI must be aware of the hazards associated with TDI, the appropriate emergency procedures, and their individual responsibilities in the event of an emergency.

The primary response to any release of TDI, whether a transportation incident or an in-plant spill, is to evacuate all unprotected people to a safe location. Only then should properly protected and trained personnel evaluate, contain, stop, clean up, and decontaminate any spill. The odor threshold of TDI is above the established exposure limits for TDI.

Depending upon the size, location and type of release, government agencies or authorities may require notification. In the United States, transportation incidents involving TDI must be reported to the National Response Center (NRC) (1-800-424-8802) for any release over the reportable quantity of 100 lbs. (approximately 10.0 gallons). This is a requirement of (U.S.A.) Federal CERCLA regulations.

Any release to the environment of over 100 lbs. must be reported to the NRC and the local planning commission as outlined under EPCRA regulations (U.S.A.). Regulations involving the release of hazardous chemicals is continually evolving, therefore, it is important that all companies handling TDI be aware of the current legislative requirements in each jurisdiction.

Each plant should have a system for dealing with emergencies within the plant. Such systems are only effective if regularly practiced. It is appropriate to form a plant fire crew and emergency team, so a well- trained team can quickly address an emergency. Everyone, however, should be aware of the hazards involved and the limitations of self-help. The priority should always be to save life rather than limit physical damage.

Areas should not be considered free of diisocyanate vapors until the area has been monitored.

Spills and Leaks

Only properly trained and equipped personnel (see Section 5) should attempt to clean up spills and leaks. The spill should be contained, and the leak stopped to prevent further contamination.

It is necessary to distinguish between minor incidents that may occur in a laboratory or a workshop handling TDI regularly, and major spills involving, for example, a bulk tank truck. The most important criterion for distinguishing between the two is the ability of the personnel on the spot to deal with the occurrence, rather than the actual size of the incident.

Minor incidents

For small spills or leaks, trained people wearing appropriate PPE and respiratory protection should ventilate the area by opening doors and windows, then completely cover the spill with an absorbent material such as an all-purpose oil absorbent, dry sand, or cat litter.

Use more than enough absorbent material to absorb all of the liquid TDI. Shovel or scoop the absorbent into another open top container and remove it to a safe location for neutralization. Do not tightly seal this container since the TDI will react with any moisture present and generate CO2 gas, which could cause a sealed container to burst. After the drums are moved to a safe area, fill the container with an appropriate neutralizing solution and allow it to stand at least 48 hours. After 48 hours, the container may be closed. The container should remain vented, however, to prevent any pressure build-up. The contents of the container should be properly disposed of (See Section 9).

After the absorbent has been shoveled from the spill site, the site should be washed and scrubbed down with a liquid neutralizer. Once the area is clean, it should be tested for diisocyanate vapors. If TDI vapors continue to be present, the decontamination should be repeated until the area is free of TDI vapors.

Decontaminating or neutralizing solutions are mixtures of agents that react with TDI and the agents that promote the reaction. The choice of solution will depend on the location (inside or outside), temperature (below or above freezing), and the flammability requirement for the intended use. A typical decontaminating solution can be made by mixing water (90 – 95 vol%), household ammonia (3 – 8 vol%), and liquid detergent (1 – 7 vol%). The water and ammonia will react with the TDI to form polyurea solids and CO2 gas, while the ammonia and detergent help promote the reaction. This solution works well indoors at normal room temperatures. Solid neutralizers, which are neutralizers premixed with an absorbent, may be used for the quick cleanup of very small spills. It is important to note the hazards and regulatory limitations of any neutralizing hazards and regulatory limitations of any neutralizing solution.

Ammonia may be regulated as a hazardous material. Before using ammonia, refer to any exposure limits and applicable regulations. The use of sawdust in combination with any decontaminate solution may cause auto-ignition.

Large spills

For large spills of TDI, a “state of emergency” must be declared as noted in the Risk Management Plan. This may require notification of local emergency response services such as the fire department. Such an event should be factored into every TDI user’s community awareness program.

All persons should be evacuated to a safe location. Properly trained and equipped personnel should then isolate and contain the spill. TDI should be contained and not be allowed to flow into any sewers or waterways.

Once the spill has been isolated and contained, the appropriate clean-up procedures should be used to remove or decontaminate the TDI. For specific instructions or assistance, the BASF emergency help line is available 24 hours a day in the United States (1-800-832-4357). For transportation incidents in the United States, the American Chemistry Council (ACC) operates CHEMTREC.

The CHEMTREC number (1-800-424-9300) is available 24 hours a day and is on all BASF Bills of Lading and SDSs. A call to CHEMTREC will set the emergency response notification process in motion and provide emergency response information to response personnel. A list of emergency response contact numbers for the United States, Canada, and Mexico can be found in section 1 of this handbook.

TDI Involved in Fires

All involved personnel must put on self-contained breathing apparatus and complete chemical protection. (I.e., rubber gloves, boots, goggles, and protective clothing.) All non-essential personnel must evacuate the immediate area. The fire should be extinguished using one of the following:

a) Dry chemical powder
b) Protein-based foam
c) CO2 extinguisher
d) Large quantities of water

Once the fire is extinguished, the next step is to prevent any material that spilled from spreading by using collecting containers and absorbers such as sand or earth.

The use of water or foam to extinguish the fire and cool the container makes it likely that moisture will enter the damaged tank or drum. Since water reacts with TDI to form solid polyureas and CO2, the danger exists that after the damaged area is plugged, a pressure build-up can occur. To prevent damage to the tank, it must be vented.

Depending on the condition of the tank and / or vehicle, the TDI product should be transferred to another container for disposal. This new tank must also be vented. In any case, the TDI product should not be shipped until the degree of water contamination is clarified.

If the TDI product is stored in the vicinity of fire but TDI is not directly involved in the fire, the container should be moved clear of the area. If the container or tank cannot be moved away from the fire, a water curtain should be positioned between it and the fire. If this cannot be accomplished safely, the tank should be cooled using a direct water spray. This should prevent damage to the tank body and its contents.

 

Pressurized Drums

A bulging drum of TDI should be assumed to be the result of contamination of the product, usually with water. This slow but unstoppable reaction with a diisocyanate produces CO2, which increases the pressure inside the container. Since it is not easy to judge the acute risk of bursting, the drum under pressure should not be moved. A tarp should be placed over the drum.

It is necessary to relieve the pressure safely before the drum bursts. This is best accomplished by puncturing the top of the drum with a long-handled spike. Some response companies have specialized drum puncturing devices. During this action, all uninvolved persons must be removed from the area and the working personnel must have complete chemical protection.

The punctured drum must then be placed in an oversized drum with pressure venting capabilities. Remember that the original contamination will probably continue to cause a pressure increase, so the container must be regularly vented using proper safety precautions. Contact BASF for disposal recommendations.

 

Chemical Reactions

The combination of polyol and diisocyanate components yields large amounts of heat and gas evolution. An evacuation of the immediate surroundings should be considered due to potential large amounts of heated TDI vapors that can be evolved. The reaction, once begun, cannot be stopped and the goal must be to prevent pressure build-up by venting. In most instances, a controlled venting via the safety valve may not be possible because the safety valve may become plugged with foam or solids. If possible, stop uncontaminated material from entering the reaction by pumping it into a separate vessel.

Although difficult with insulated tanks, cooling should be attempted. Any vapors should be knocked down with water spray or foam. The reaction should proceed to end with a minimum of heat and vapor evolution. All personnel involved must wear complete protective equipment.