Choosing a sterilant for bulky and heat-sensitive items: Which method is most effective for sterilizing mattresses and plastic Petri plates without heat or moisture damage?

Introduction / Context:
Many medical and laboratory items are heat- or moisture-sensitive, bulky, or porous. Selecting an appropriate sterilization method requires understanding penetration, material compatibility, and proven lethality, including sporicidal action. This question focuses on mattresses and plastic Petri plates—classic candidates for low-temperature gas sterilization.

Given Data / Assumptions:

• Mattresses are bulky and porous; plastics may deform at high temperatures.
• Sterilization must achieve microbial kill including spores, not just surface decontamination.
• Method should penetrate fabrics and complex geometries without heat.

Concept / Approach:
Ethylene oxide (EtO) is a low-temperature, vapour-phase sterilant that alkylates DNA and proteins, achieving high-level sterilization with excellent penetration into porous materials and packaged items. Alternatives such as UV-C or liquid disinfectants have limited penetration or require immersion, which is impractical for mattresses and can damage or leave residues on plastics.

Step-by-Step Solution:
1) Define the challenge: sterilize porous/bulky and heat-sensitive items.2) Assess EtO: gaseous, low-temperature, penetrates packaging and fabrics, validated sterilant → suitable.3) Assess chlorine and glutaraldehyde: effective disinfectants, but surface-limited or immersion-based; poor for mattresses and impractical for large volumes of plastics.4) Assess UV-C: line-of-sight only with shallow penetration; shadowing prevents reliable sterilization.5) Conclude: ethylene oxide is most effective and practical.

Verification / Alternative check:
Hospital central sterile services and industry use EtO (or hydrogen peroxide gas plasma for some plastics) to sterilize heat-sensitive, porous items and sealed device sets, confirming its suitability for the items in the stem.

Why Other Options Are Wrong:

• Chlorine: surface disinfection only; not reliable for interiors of porous items.
• Glutaraldehyde: immersion required; not feasible for mattresses.
• UV-C: poor penetration; shadows limit efficacy.
• Dry heat: damages plastics; heat-sensitive and bulky items unsuitable.

Common Pitfalls:
Overestimating UV penetration; assuming high-level liquid disinfectants equal terminal sterilization for large porous objects.

Final Answer:
Ethylene oxide gas sterilization.