When, exactly, do hazardous materials officially enter and leave the transportation system? Though that might seem to be a fairly straightforward matter, it's one that has sometimes left regulators embroiled in disputes.

In an effort to clarify the issue, at least from a legal standpoint, the Department of Transportation's Research and Special Programs Administration (RSPA) has issued a final rule defining what functions and activities fall under the Hazardous Materials Regulations as well as what exactly constitutes transportation (for the record, it begins when a carrier takes possession of a hazardous material and continues until the hazmat is delivered to the destination indicated on the shipping documentation).

The ruling, which takes effect Oct. 1, 2004, will add "pre-transportation functions" to the list of activities covered by the regulations. Pre-transportation functions include determining the hazard class of a material; marking and labeling packages and providing placards; preparing shipping documentation and emergency response information; and blocking, bracing and segregating hazardous materials in freight containers or transport vehicles.

The rule also attempts to clarify when the hazmat regulations apply and when they don't. Transportation functions that come under the regulations' purview include loading and unloading operations when performed by carrier personnel and the storage of a hazardous material after the carrier takes possession and before it's delivered to its destination. Activities to which the regulations do not apply include storage of a hazardous material at a shipper facility prior to a carrier's taking possession of the material; unloading operations conducted by consignee personnel after a hazardous material has been delivered; and storage of a hazardous material at a consignee facility after delivery.

It's important to note that a material's regulatory status could shift several times in the course of a journey. In a recent newsletter, the National Industrial Transportation League pointed out that under the new rule, a hazardous material being held at an intermodal facility awaiting transportation or in temporary storage-in-transit would be subject to the regulations, but material in storage for repackaging would not. However, the repackaging process itself would be subject to the regulations because it would be classified as a pre-transportation function.