Which standard governs Legionella risk documentation in ventilation systems?

• A. Documentation is optional.
• B. Only requires annual testing but no standard.
• C. Requires ISO 9001.
• D. Documentation must comply with ASHRAE Standard 188.

Answer: (D)

The key idea is that Legionella risk management for building water systems is governed by a formal standard that requires a documented program. ASHRAE Standard 188 provides this framework, outlining a written Legionella risk-management program for building water systems. It calls for identifying where aerosols can be generated (such as cooling towers, humidification equipment, and other water-using components in ventilation-related systems), establishing appropriate control measures, assigning responsibilities, and maintaining records of risk assessments, controls, maintenance, monitoring, and verification. This means documentation isn’t optional or limited to annual tests; it’s a structured, ongoing program that must be documented and kept up to date.

ISO 9001 is a general quality-management standard and doesn’t specifically address Legionella risk documentation in ventilation or building water systems. Saying documentation is optional or relying on annual testing alone doesn’t meet the requirement of a formal, documented risk-management program defined by ASHRAE 188.