Pda Technical Report 82 May 2026

The Challenge: Pharmaceutical water systems (Purified Water, Water for Injection) require routine sanitization to control biofilm and microbial proliferation. The industry standard for thermal sanitization typically involves heating the water to 80°C or higher and circulating it at high velocities (turbulent flow, Reynolds number > 10,000) to ensure uniform temperature distribution and heat penetration to all wetted surfaces.

However, older facilities or systems with design limitations (e.g., pump cavitation issues at low flow, dead legs, or undersized pumps) may not be able to achieve or sustain these high flow rates during thermal treatment. Historically, regulators viewed low-flow sanitization with skepticism due to concerns about "cold spots" where bacteria could survive. pda technical report 82

The Solution: TR 82 bridges the gap between engineering theory and practical reality. It acknowledges that while high-velocity turbulent flow is preferred, effective thermal sanitization is still achievable at lower velocities if specific temperature mapping and validation protocols are followed. TR 82 serves as a defense for companies

TR 82 serves as a defense for companies utilizing this non-standard method. During an inspection, a regulator may question why a water system is sanitized at low velocity. The report clarifies that trickle sterilization is not

The Regulatory Defense: By following TR 82, a manufacturer can present a Validation Report demonstrating:

The report clarifies that trickle sterilization is not a shortcut but a validated alternative for constrained systems. It emphasizes that this method is often necessary to prevent mechanical failure (e.g., pump damage) that might occur if the system is forced to run at high velocity while hot.

TR 82 explicitly states what regulators will ask during an inspection: