Disinfectant spectrum — All of the following agents are sporicidal (capable of killing endospores) EXCEPT:

Introduction / Context:
Choosing the right chemical for high-level disinfection or sterilization requires awareness of sporicidal activity. Endospores resist many routine disinfectants; only a subset of chemicals are validated as sporicidal under correct conditions (concentration, temperature, exposure time).

Given Data / Assumptions:

• We compare high-level agents (aldehydes, ethylene oxide) with intermediate agents (alcohols).
• “Sporicidal” implies proven kill of bacterial spores in standardized tests.

Concept / Approach:
Glutaraldehyde and formaldehyde (aldehydes) crosslink proteins and nucleic acids, achieving sporicidal effects with sufficient exposure. Ethylene oxide gas alkylates cellular constituents, sterilizing heat-sensitive equipment (including spores). Alcohols (ethyl, isopropyl) are excellent skin antiseptics but are not reliably sporicidal.

Step-by-Step Solution:

Verification / Alternative check:
Disinfection guidelines categorize alcohols as intermediate-level (bactericidal, tuberculocidal, virucidal) but not sporicidal; aldehydes and ethylene oxide meet sporicidal criteria with validated protocols.

Why Other Options Are Wrong:

• Glutaraldehyde: sporicidal at recommended exposure (e.g., ≥2% solutions).
• Ethylene oxide: sterilant gas for heat-sensitive instruments.
• Formaldehyde: sporicidal with adequate concentration/time.

Common Pitfalls:
Assuming strong “kill” on vegetative cells equals spore kill; spores need higher-level chemistry or heat.

Final Answer:
Alcohol