6. Shipment of TDI
Although TDI is a hazardous material in terms of reactivity and toxicity, it can be distributed and handled safely, provided that appropriate precautions are observed.
Regulations
The shipment of TDI – and TDI-containing products is subject to strict regulations within most countries in Europe and North America. In addition, the international movement of these products by road, rail, or sea is subject to international agreements, which lay down specific requirements concerning shipment. The transportation equipment for MDI products must meet the design and construction requirements of national and international regulations. Table 5 is a partial list of transportation regulations.
Table 4: Transportation Regulations
| Regulation |
Description |
| DOT |
United States Department of Transportation Rules Governing the Transport of Hazardous Materials (HMR) |
| ICAO |
International Civil Aviation Organization |
| IMDG |
International Maritime Dangerous Goods Code |
| IMO |
International Maritime Organization |
| TDG |
Canadian Regulations Concerning the Transport of Dangerous Goods by Land |
TDI is classified in all countries and internationally as UN2078, class 6.1, Packaging Group II, Symbol: Poison. Accompanying all shipments of TDI is an emergency response guide in North America or a Tremcard (transport emergency card) in Europe.
For shipments of TDI, BASF uses only professional transportation companies whose personnel are competent and well trained in the handling of TDI. Accompanying all shipments of TDI products is an emergency response guide and/or a Bill of Lading. CPI has published recommendations for the transport of TDI in the United States. See Reference: Guidelines for Receiving and Unloading TDI.
Shipping Containers
TDI products are generally shipped in 550 pound steel drums or in bulk. Bulk deliveries are generally made in tank trucks (road tankers and demountable tanks) containing approximately 20 tons (44,000 pounds) or tank cars (rail tank wagons) containing up to 86 tons (approx. 190,000 pounds). Each container clearly displays a tag, placard, and / or label warning of potential hazards.
TDI containers must remain closed until use, to prevent moisture contamination. Only trained individuals wearing the appropriate PPE are allowed to open containers of TDI. When a TDI container is opened, make-up dry air or nitrogen should be provided.
BASF has the responsibility to ensure that all TDI shipments leaving BASF facilities are properly prepared to comply with all the appropriate regulatory transportation requirements. Depending on the method of transportation, the rail carriers, truck lines, or airlines are responsible for the safe shipment of TDI from the shipping point to the final destination. Emergency situations in route, such as accidents or leaking containers, must be reported immediately to appropriate regulatory authorities and to BASF.
Unloading Operations
The operation of unloading (or loading) any tank truck, iso tank container, tank car, or small container of TDI is a potentially hazardous operation. Unloading facilities must be designed and located, giving due regard to the potential hazards of TDI products.
Written operating procedures covering all aspects of the unloading operation of TDI products must be prepared and available to all involved parties. All necessary PPE and emergency equipment must be available for the unloading operations. Personnel must be trained in the procedures and correct use of all protective clothing and emergency equipment (See Section 5).
Bulk Unloading
Unloading of TDI products from bulk containers should be performed with a self-priming, seal-less pump, and a vapor return line connected between the storage tank and the bulk delivery container. The seal-less design eliminates potential seal failure. Dry nitrogen or dry air must be available to purge the unloading lines and vapor return line after unloading is completed. The storage tank must be equipped with a high-level device to stop the unloading automatically if the maximum tank level is reached.
If dry air or nitrogen pressure is used to transfer TDI from a bulk container to the storage tank, the pressure must be regulated below the maximum safe operating pressure of the bulk container. The storage tank vent must be sized accordingly. After disconnecting hoses, all exposed fittings and hoses must be protected with caps or plugs. The dimensions and physical arrangement of bulk containers vary; contact your local BASF representative for unloading (and loading) diagrams; procedures are available for MC-307 tank trucks and 20,000-gallon rail cars.
Drum Handling
Drums should be handled and unloaded carefully to prevent damage. Operators must wear the proper personal protective equipment during handling. Drums should be transported by lifting to avoid damage caused by sliding or rolling. Only equipment designed for handling drums should be used. Forklift trucks equipped with “parrot beaks” or drum clamps are ideal. Each shipment should be closely examined for damaged or leaking drums. If leaking drums are found or damage occurs in movement, refer to Section 8 for procedures on proper handling of leaks or spills. Improperly equipped fork trucks may result in punctured or damaged drums.
Liquid TDI products which have solidified through cooling should be liquefied by careful heating as soon as possible. For correct heating methods and temperatures, see the appropriate Technical Data Sheet.
Drums can be emptied using a standard immersion pump or gravity discharged. Air displaced from the receiving tank should be discharged to the vapor exhaust system. A silica gel filter can be connected to the open drum vent (small bung) to prevent drums from collapsing while being emptied. This filter will also prevent moisture contamination from entering the drum. The opening of TDI drums should be minimized to reduce moisture contamination.
Water contamination of drums must be avoided. This contamination with water can result in a pressure build-up in closed containers by the generation of CO2 gas from the water-TDI reaction. Drums showing evidence of pressure build-up must be vented immediately with caution, otherwise there is a potential for a violent drum rupture.
Refer to Section 7 for storage of TDI drums and Section 9 for recommendations on the neutralization and disposal of empty TDI drums.
Sample Shipments
In order to ensure that small packages are safe for transport, customers should contact BASF for information concerning the regulations and restrictions that apply. This is especially true when the customer does not normally ship small samples of potentially hazardous materials and may not have the proper packaging material. BASF will not accept unsolicited samples of TDI.