Currently, and only until December 31, 2013 when it will cease to exist (unless an extension requested by US DOT to December 31, 2015 is granted), there is only one category of Other Regulated Material.  In the distant past (known as “The 90’s”) however, there were five of them:  ORM-A through ORM-E.  What remains today is the one known as Other Regulated Material-D or ORM-D.

The definition of ORM at 49 CFR 171.8 identifies it as an Other Regulated Material and refers to §173.144 (see below) which goes on to define solely the ORM-D; no reference is made to the other types of ORM.  While they no longer impact the Hazardous Material Regulations, an understanding of the history the HMR does help to develop a full appreciation of the existing regulations.  To fulfill your curiosity the full list of Other Regulated Materials – both past and present – are identified below:

• ORM-A means a material which has an anesthetic, irritating, noxious, toxic, or other similar property.  It is regulated due to concern that a release during transportation could cause extreme annoyance to passengers and crew of transport vehicles.  No longer in use.
• ORM-B means a material, including a solid when wet with water, that could cause significant damage to the transportation vehicle if it were to leak during transportation. An ORM-B material (no longer in use) is:

1. Specifically designated by name in §172.101, and/or;
2. A liquid that has a corrosin rate exceeding 0.250 inch per year (IPY) on non-clad aluminum.

• ORM-C means a material which has other inherent characteristics not described as an ORM-A or ORM-B, but which make it unsuitable for shipment, unless properly identified and prepared for transportation.  ORM-C materials are specifically designated by name at §172.101.  No longer in use.
• ORM-D in use at least until December 31, 2013 and defined at §173.144 means a material such as a consumer commodity, cartridges, small arms or cartridges, power devices which, although otherwise subject to the regulations of this subchapter, presents a limited hazard during transportation due to its form, quantity and packaging.  It must be a material for which exceptions are provided in Column (8A) of the §172.101 Hazardous Materials Table.
• ORM-E means a material that is not included in any other hazard class but is subject to the requirements of this subchapter.  Materials in this class (no longer in use) include:

1. Hazardous Waste, and;
2. Hazardous Substances.

The list above is more of a historical record than an identification of current regulations since all but the ORM-D have been eliminated and it will be no more within a few more years.  The Hazardous Material Regulations (HMR) of the US DOT are always changing, and it is your responsibility to stay on top of them, my training will help you to do that.  Contact me with questions about the HMR or the Hazardous Waste regulations of the US EPA.