What is a Hazardous Chemical Waste?

A person who generates a waste must determine if that waste is hazardous and subject to regulation by the Maryland Department of the Environment (MDE). This waste determination is conducted initially by evaluating the waste material against a series of specific waste chemicals, which can be found in COMAR 26.13.

If a waste does not appear on these lists, the person must determine if the waste exhibits any of the characteristics of hazardous waste; ignitability, corrosivity, reactivity and/or toxicity. Proper waste determination is highly dependent on the use of a given material.

I. Hazardous waste is a solid waste which exhibits one or more of the hazardous waste characteristics for:

Ignitability

1. A liquid, other than an aqueous solution containing less that 24 percent alcohol by volume, and has a flash point less than 60 degrees Centigrade (140 degrees Fahrenheit); or
2. Not a liquid but is capable under standard temperature and pressure, of causing fire through friction, absorption of moisture or spontaneous chemical changes, and when ignited burns vigorously and persistently that it creates a hazard; or
3. An ignitable compressed gas as described in 49CFR 173.300 and as determined by the test methods described in that regulation; or
4. An oxidizer as defined in 49CFR 173.151

Corrosivity

1. An aqueous liquid that has a pH less than or equal to 2 or greater than or equal to 12.5; or
2. A liquid that corrodes steel at a rate greater than 6.35 mm per year at a temperature of 55 degrees Centigrade (130 degrees Fahrenheit) as specified in the appropriate test method.

Reactivity

1. Any hazardous material that is normally unstable and readily undergoes violent change without detonating; or
2. It reacts violently or forms potentially explosive mixtures with water; or
3. Any cyanide or sulfide bearing waste that when exposed to pH between 2 and 12.5, can generate toxic gases, vapors or fumes in at quantity sufficient to present a danger to human health or the environment; or
4. It is capable of detonation or explosive reaction if it is subjected to at strong initiating source or if heated under confinement; or
5. It is readily capable of detonation or explosive decomposition or reaction as standard temperature or pressure; or
6. An explosive as defined in 49CFR 173.51, 49CFR 173.53, or 49CFR 173.88.

Toxicity

The criteria for toxicity may be fulfilled if one or more of the following chemicals are present in a solution or compound at a concentration at or above the specified regulatory level:

II. It is listed as a hazardous wastes from discarded commercial products, off-specification species, container residues, and spill residues (P & U Listed Wastes)

III. It is listed as a hazardous waste from non-specific sources (F Listed Wastes)

IV. It is listed as a hazardous waste from specific sources that include primarily industrial sources. (K Listed Wastes)