May 26, 2011

PPG and NSF Warn Against Using Uncertified Chlorine Tablets in Pools

Free booklet highlights safety and health risks from improper use of chlorinator systems

As commercial and community pools across the nation prepare for summer, NSF Intl. and the ACCU-TAB system commercial pool water treatment group of PPG Industries are working to inform aquatic health inspectors and pool owners and operators about the importance of using properly certified chlorine tablets. They have co-published a free guide called “For Safety’s Sake” that explains how to spot improper operation and why substitute tablets can be dangerous.

“The start of pool season is a critical time for NSF and for health inspectors to educate pool owners and operators on the importance of using only chlorine tablets certified for use as part of an NSF-certified feeder system,” said Dave Purkiss, general manager of the water treatment and distribution products program at NSF. “Failure to use tablets certified as part of an NSF Standard 50 chemical feeder system cannot only put swimmers’ health at risk, but it can also place the pool out of compliance with state and local health codes that require NSF/ANSI Standard 50 certification.”

According to NSF and PPG, substituting generic or “knock-off” tablets may create health and safety risks for patrons that could lead to health code violations and shutdowns. It can result in the under- or over-chlorination of water due to varying delivery rates, and it can increase the potential for noxious fumes and even fire or explosion caused by mixing incompatible chemicals.

“The use of mismatched ‘knock-off’ tablets in a chlorinator system can not only void the manufacturer’s warranty and give uncontrolled delivery rates, but it can result in an inadvertent mixing of incompatible chemicals that may generate heat, release toxic gas and potentially cause a violent detonation in the feeder,” said Dr. Stan Pickens, PPG senior research associate for the Accu-Tab chlorination system.

The results can be catastrophic, as such explosions could damage equipment and cause injuries to personnel nearby. As a result, it is important not only for pool owners to be aware of the dangers, but also for health inspectors to be on the lookout for violations.

“The responsibility lies with pool operators to thoroughly understand and follow their chlorinator manufacturer’s product guidelines in order to prevent health and safety risks for patrons and operators,” Pickens said.

To download or order a copy of the free booklet, visit