The DDC is an internal system developed by the University of Minnesota Chemical Waste Registry Searchable Database to classify substances through a two-part designation code: the Hazard Class and the Disposal Type. For example, if a substance has a DDC of 02LI then it is a liquid inorganic acid.
Hazard Class. The first part of the DDC consists of two digits that designate the chemical’s primary hazard as it relates to the Department of Transportation (not all sequential numbers are used):
01 Corrosive Bases 06 Combustibles 12 Organic Peroxides
02 Corrosive Acids 07 Flammable Gases 14 Explosives
08 Flammable Liquids
03 ORM-A (Other Regulated Materials-A) 09 Flammable Solids 16 Oxidizers
05 ORM-A (Other Regulated Materials-A) 11 Non- Flammable Gases 18 Poisons
Disposal Type. The second part of the DDC consists of two letters that further describe the chemical/physical characteristics of the substance, or defines the type of disposal or treatment methodology required.
NH NonHazardous – dispose in regular sewage or trash
BS Bulkable Solvent HP Pesticide PX PCB Contaminated
CG Compressed Gas LI Liquid Inorganic RX Radioactive Material
CL Chlorinated Organic Liquid LO Liquid Organic SC Sulfuric/Chromerge
CN Cyanide NA Nitric Acid SI Solid Inorganic
CS Chlorinated Organic Solid PA Poison A SO Solid Organic
DX Dioxin Containing PB Poison B SS Shock Sensitive
EX Explosive PI Poisonous Inorganic TS Trade Waste Incinerator
FB Fuel Blending PF Peroxide Former WS Water Sensitive
HM Heavy Metal PO Pourable Oil
FL Flammable Liquid FS Flammable Solid