For years ozone has been a popular disinfectant for removal of pathogens including Giardia and Cryptosporidium cysts.
Today its applications are broadening significantly in drinking water and water reuse applications for purposes that include control of taste and odor and destruction of emerging contaminants, such as pharmaceuticals.
As the use of ozone grows, utilities need to be aware of its potential hazards and how to protect treatment system operators through safe handling practices. Toward that end, the International Ozone Association — Pan American Group has created an Ozone Safety Training Video that gives essential guidance on best practices for system operation, risk mitigation and emergency response.
Jim Lauria, president-elect of the IOA and vice president of sales and marketing with Mazzei Injector Company, is helping lead the charge to ensure that ozone is both effective and used safely in municipal water treatment.
With a background in engineering, marketing and storytelling, he brings a broad perspective to the importance of training operators to handle ozone systems safely. He highlighted that imperative in an interview with Treatment Plant Operator.
TPO: How is ozone treatment expanding in the municipal water sector?
Lauria: In the past it was used mostly for disinfection, often as adjunct to chlorine or UV. Now it’s being looked at for removing cyanotoxins, for removal of taste and odor, for iron and manganese precipitation. For treating emerging contaminants ozone treatment is being combined with biologically active filtration. It breaks down longer-chain organic molecules so that they can be digested by microorganisms on the filter substrate.
TPO: Why is ozone preferable to other methods of treating these contaminants?
Lauria: First is the benefit of destruction versus concentration. For example, reverse osmosis treatment for organic compounds basically concentrates the contaminants, and then the waste has to be disposed of. Ozone with BAF actually destroys the contaminants. It’s produced on site, so there’s no need for storage of chemicals. It also breaks down into oxygen, so there are no harmful disinfection byproducts. Ozone is also a very strong oxidant that reacts quickly and works very well in precipitating iron, manganese and other nuisance constituents. In addition, it is more cost-effective in some ways.
TPO: How is ozone more cost-effective than other treatments?
Lauria: Ozone contributes to operational efficiency and long-term cost savings by reducing usage of chemicals such as chlorine and coagulants, and by lowering maintenance frequency through improved process control. It also minimizes sludge production, saving water and reducing disposal costs. And it supports energy-efficient designs, especially in sidestream injection and venturi-based systems.
TPO: What led your organization to make ozone safety training a key initiative?
Lauria: In a recent executive committee strategic planning session, it became clear that as ozone gains momentum in water treatment and reuse applications, we need to make sure that safety is front and center. Ozone is highly effective but also requires careful handling. As president-elect, I felt that one of our most important contributions to the industry would be promoting safety through practical, accessible training.
TPO: What specifically are the safety concerns around ozone?
Lauria: Once ozone is in the water, there is no problem, but if operators are exposed to airborne ozone, it can cause a range of effects including eye and respiratory tract irritation, chest tightness and shortness of breath, headaches and coughing. Of more concern, exposure at a relatively low level can cause lung tissue damage and even death.
TPO: How does ozone get into the air?
Lauria: Not all the ozone gets into the water. With a bubble diffuser, about 90% of the ozone is added to the water; with a sidestream injection system, about 95% gets in. In either case, there is a certain amount of fugitive gas. Typically, the treatment system has an ozone destructor with a catalyst that converts the ozone to oxygen. But if there is a leak in the system, or if the catalyst is compromised and is not working properly, fugitive ozone can exit the system. Something has to be wrong for that to occur, but it can happen, and operators need to understand that.
TPO: Are there any other potential hazards?
Lauria: Many systems designed to manufacture ozone use pure oxygen, so obviously from a flammability standpoint, safety protocols need to be followed. For example, there can be no smoking or open flames in the area. To further prevent ignition hazards, operators should use spark-free (nonferrous), clean tools and wear suitable clean clothing. Facilities must have ambient oxygen alarms, and working fire extinguishers should be readily available.
TPO: Why is ozone safety training especially important right now?
Lauria: As the use of ozone expands, many operators may be encountering it for the first time, or inheriting systems with limited documentation. Our goal is to provide a tool that helps bridge that gap by standardizing safe practices and supporting a strong safety culture across the industry.
TPO: What does the safety training video cover, and who is it designed for?
Lauria: The video is designed for municipal treatment plant operators — those on the front lines of managing ozone systems. It covers everything from the basic properties of ozone and system design considerations to leak detection, personal protective equipment, and emergency response protocols. It’s not meant to replace hands-on training or standard operating procedures but to supplement them by reinforcing best practices and increasing operator confidence when working with ozone.
TPO: Does your association also offer hands-on training?
Lauria: We try to have operators become members and attend industry workshops. We conduct a workshop at our annual conference. Another thing we’re pursuing is to become accredited as an organization that can offer continuing education units. We’re taking the steps through our municipal committee to get the accreditation so that operators attending our workshops can attain CEUs.
TPO: What are some basic safety precautions operators have to observe when dealing with ozone treatment systems?
Lauria: You can smell ozone, so operators should keep their nose attuned and avoid walking into a room where ozone is present. They should never go into a potentially hazardous situation alone. They also need to make sure the catalysts for the ozone destruction unit are up to date, and follow a maintenance protocol. Before maintenance, it is critical to purge the piping, generators and contactors to prevent accidental exposure. The ozone generation room should have at least two regularly calibrated ambient ozone analyzers with appropriate alarm settings. Portable ozone monitors should be used to detect leaks during inspections and maintenance.
TPO: What was involved in putting the safety video together?
Lauria: The Ozone Safety Training Video is a 46-minute instructional resource created by a multidisciplinary team of experts, including consulting engineers, municipal operators, professional trainers and ozone equipment manufacturers from the IOA-PAG Municipal Committee. It’s designed to help utility staff understand and apply best practices for the safe handling of oxygen and ozone.
TPO: How does this safety initiative fit into your association’s larger mission?
Lauria: Our mission is to promote the development, understanding and application of ozone and related oxidants. That’s not just about pushing technology; it’s about protecting the people who make that technology work. We want to be a trusted resource for utilities, engineers and operators, and this training video is a step in that direction.
TPO: How does your own company support that mission?
Lauria: As part of the startup documentation for every ozone dissolution system we produce, we include a direct link to the safety training video. During commissioning and operator training, we consider it a critical supplement to our system-specific instructions. By pointing operators to this video, we make sure they have access to trusted guidance long after the installation is complete.
TPO: Where can utilities and operators access the video?
Lauria: The training video is freely available on the IOA-PAG website at ioa-pag.org/safety-training-video. We encourage utilities to include it onboarding, refresher training and toolbox talks. If they have questions or need support, we’re here to help.
