Question 16 of 18: Managing Biomedical Wastes — Liquid vs. Solid

Question 16: Managing Biomedical Wastes — Liquid vs. Solid (6 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.

Biomedical waste management follows the same general hierarchy as hazardous waste — segregate at source, treat to render non-infectious, and dispose appropriately — but the specific handling method differs sharply between the solid and liquid fractions because the infection-control problem each poses is different. Solid biomedical waste (sharps, contaminated dressings/gowns, laboratory cultures, anatomical waste) is first segregated at the point of generation into colour-coded, puncture-resistant (for sharps) containers, kept separate from general municipal solid waste throughout on-site storage and transport. It is then rendered non-infectious primarily by autoclaving (steam sterilization) for most general biomedical solid waste, or by incineration for pathological/anatomical waste and for materials autoclaving cannot adequately treat; the treated residue (sterilized or incinerator ash) can then usually be landfilled as ordinary solid waste. Liquid biomedical waste (blood, body fluids, contaminated liquid laboratory waste) is managed differently because it cannot be autoclaved or incinerated as a bulk stream in the same way — it is typically chemically disinfected (e.g. with a hypochlorite or other approved disinfectant solution, at a controlled contact time and concentration to inactivate pathogens) before being discharged to the sanitary sewer under the facility's own discharge permit, or, where the volume is small, it may be absorbed into a solid absorbent and managed through the solid-waste (autoclave/incineration) stream instead. In both cases, the guiding CCME framework requires the treatment method to be validated as achieving an adequate log-reduction in indicator organisms before the treated waste can be released to a lower-hazard disposal pathway, and documentation of the treatment (temperature/time for autoclaving, disinfectant dose/contact time for liquids) is retained as part of the facility's compliance record.