Safe Shower: A New Point-of-Use Strategy for Reducing Legionella Risk in Building Water Systems
By Lidor Zabari, MPH
Founder & Inventor, Safe Shower®
Despite significant advances in water treatment technologies and comprehensive water management programs, Legionella remains one of the leading causes of waterborne disease outbreaks worldwide. Hospitals, hotels, long-term care facilities, and other large buildings continue to report cases of Legionnaires' disease, even where regulatory guidance and routine monitoring programs are implemented.
One of the reasons is that conventional control strategies primarily focus on the building's central water distribution system, while relatively little attention is given to the final section of the plumbing system—the point of use—where water may stagnate for extended periods before being aerosolized.
Safe Shower® introduces a novel engineering approach designed to address this critical vulnerability.
The Hidden Risk at the Point of Use
Legionella bacteria proliferate under favorable environmental conditions, particularly within biofilms and stagnant water found in plumbing systems.
Although modern buildings frequently employ centralized control measures such as thermal disinfection, chlorine dioxide, monochloramine, copper-silver ionization, or ultraviolet treatment, water may remain stagnant inside shower heads and the final section of piping between uses.
During this stagnation period, disinfectant residuals can decrease, temperatures may enter the optimal growth range for Legionella, and biofilms may continue to develop.
When a shower is activated, these stagnant waters can be among the first to become aerosolized and inhaled, particularly by vulnerable individuals.
This final meter of plumbing therefore represents an important—but often under-addressed—component of Legionella risk management.
A Different Engineering Philosophy
Safe Shower® was developed around a simple engineering principle:
Instead of focusing exclusively on treating the building's water supply, why not continuously manage the water that actually remains inside the shower system between uses?
The technology is designed to continuously recirculate stagnant water within the shower assembly while the shower is not in operation.
The recirculated water passes through an external disinfection unit before returning to the shower head, reducing the microbial load within the stagnant volume.
Rather than allowing water to remain motionless for hours or days, Safe Shower® aims to maintain a controlled recirculation cycle during idle periods.
1. Point-of-Use Protection
The system targets the location where exposure actually occurs—the shower outlet—rather than relying solely on upstream water treatment.
2. Continuous Management of Stagnant Water
Instead of waiting until the next user opens the shower, Safe Shower® is intended to manage water quality during periods of non-use, when microbial growth is most likely to occur.
3. Complementary to Existing Water Safety Plans
Safe Shower® is not intended to replace established Water Safety Plans or Legionella control programs.
Instead, it provides an additional engineering barrier that complements existing treatment technologies and monitoring practices.
4. Potential Reduction in Maintenance Burden
Routine flushing, dismantling, and disinfecting shower heads require considerable labor and operational resources.
By addressing microbial growth directly within the shower assembly, Safe Shower® may contribute to reducing maintenance requirements, subject to validation under real-world operating conditions.
5. Particularly Relevant for High-Risk Facilities
The technology may provide particular value in:
where immunocompromised individuals or large numbers of users may be exposed.
Safe Shower® incorporates a closed hydraulic recirculation concept that maintains circulation of water trapped within the shower assembly during idle periods.
The design is intended to integrate with conventional plumbing infrastructure while minimizing disruption to normal user experience.
Unlike conventional point-of-use filters—which physically remove microorganisms but require regular replacement—or routine flushing protocols that depend on operational compliance, Safe Shower® seeks to provide an automated engineering solution operating continuously between shower uses.
Public Health Perspective
Legionella prevention increasingly relies upon a multi-barrier strategy that combines:
System design
Temperature management
Residual disinfectants
Routine monitoring
Risk assessment
Operational maintenance
Emerging evidence suggests that additional attention to point-of-use conditions may further strengthen building water safety programs.
Solutions specifically addressing stagnant water at the outlet may represent an important evolution in Legionella prevention strategies.
As building water systems become more complex and expectations for patient safety continue to increase, innovation must extend beyond centralized treatment technologies.
Safe Shower® represents a shift toward proactive management of water quality at the exact location where exposure occurs.
Ongoing field evaluations and future independent studies will be essential to quantify its impact on microbial water quality and Legionella risk reduction. If validated, point-of-use recirculation technologies may become an important addition to the next generation of building water safety solutions.
The final section of a building's plumbing system remains one of the least controlled environments in Legionella prevention.
By actively managing stagnant water inside the shower assembly during periods of non-use, Safe Shower® introduces a new engineering concept focused on reducing microbial risk at the point of exposure.
Rather than replacing existing control measures, the technology is intended to complement comprehensive Water Safety Plans and strengthen the multiple barriers already used to protect public health.
As healthcare facilities, hotels, and public buildings continue to seek more effective approaches to Legionella prevention, innovative point-of-use technologies such as Safe Shower® may play an increasingly important role in future water safety management.