Question 9 of 19: Four Properties of a Hazardous Waste

Question 9: Four Properties of a Hazardous Waste (4 marks)

Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.

Hazardous waste regulatory frameworks (including Canadian federal and provincial regulations informed by CEPA) classify a waste as hazardous if it exhibits one or more of four characteristic properties:

1. Ignitability — a waste that is a liquid with a flash point below a regulatory threshold (commonly 60–65°C), a non-liquid capable of spontaneous, sustained combustion, or an ignitable compressed gas or oxidizer.
2. Corrosivity — an aqueous waste with pH ≤ 2 or ≥ 12.5 (strongly acidic or alkaline), or a liquid that corrodes steel at a specified rate, capable of destroying living tissue or containment materials on contact.
3. Reactivity — a waste that is normally unstable and readily undergoes violent change, reacts violently with water, generates toxic gases when mixed with water, or is capable of detonation.
4. Toxicity — a waste that, based on a standardized leaching test (e.g. TCLP) or acute toxicity data, contains a hazardous concentration of a toxic constituent (heavy metals, pesticides, volatile/semi-volatile organics) that could leach into groundwater or harm human health/the environment.