What Is an Ozone Machine? How It Works and When we Use Ozone for Odour Removal & Disinfection

Relief Restorations
Jul 5
13 min read

Introduction

Ozone (O₃) is a powerful molecule composed of three oxygen atoms. Naturally occurring in the upper atmosphere, ozone plays a vital role in protecting us from harmful ultraviolet rays. However, it also has important applications here on the ground, particularly in the restoration and remediation industry. When generated in controlled amounts, ozone gas can effectively neutralize odours, bacteria, viruses, and even mould spores.

Maintaining healthy indoor air quality is a critical part of any restoration project. Whether a property has experienced fire damage, water intrusion, mould growth, or prolonged odour exposure, lingering contaminants in the air can pose both health risks and comfort concerns for occupants. That’s where ozone machines come into play, offering a deep-cleaning solution that reaches areas traditional methods may miss.

In this article, we’ll explore what ozone machines are, how they work, when and why they’re used in restoration settings, and the important safety considerations that come with their use. Whether you’re a homeowner dealing with stubborn odours or a property manager handling post-remediation cleanup, understanding ozone treatment can help you make informed decisions about indoor air restoration.

What Is an Ozone Machine?

An ozone machine, also known as an ozone generator, is a specialised device designed to produce ozone gas (O₃) for the purpose of purifying indoor air and surfaces. Ozone is a highly reactive molecule that seeks out and neutralizes odours, bacteria, viruses, mould spores, and other airborne contaminants. When used properly, ozone treatment can provide a powerful solution for deep-cleaning and odour elimination, especially in spaces affected by fire, water damage, mould, or biological contamination.

Types of Ozone Generators

There are several types of ozone generators, each using a different method to produce ozone gas:

Corona Discharge Ozone Generators: This is the most common type used in restoration. These machines generate ozone by passing dry air or oxygen through a high-voltage electrical discharge, which splits oxygen molecules (O₂) and allows them to recombine into ozone (O₃). Corona discharge units are efficient and capable of producing large volumes of ozone.
Ultraviolet (UV) Ozone Generators: These systems use UV light at specific wavelengths to split oxygen molecules and form ozone. While generally less powerful than corona discharge machines, UV ozone generators can be effective for smaller spaces or more sensitive applications.
Cold Plasma or Electrolytic Ozone Generators: These are newer technologies used more commonly in water purification and medical settings rather than air purification. They are not typically used in property restoration due to their limited output for large-scale odour control.

Common Features of Commercial-Grade Units Used in Restoration

Ozone machines used by restoration professionals are built for performance and durability. Some of the key features include:

High ozone output (measured in mg/h or g/h) to treat large or heavily affected spaces
Integrated timers or programmable controls to set treatment durations and ensure safe operation
Built-in fans to help circulate ozone evenly throughout the space
Rugged, portable design suitable for use in homes, basements, commercial properties, or construction zones
Safety indicators and warning labels to remind users of occupancy restrictions during operation

At Relief Restorations, we only use professional-grade ozone equipment that meets industry safety standards and is operated by trained technicians. This ensures both effectiveness and the protection of your property and health.

How Does an Ozone Machine Work?

Ozone machines work by generating ozone gas (O₃), a molecule made up of three oxygen atoms. While regular oxygen (O₂) is stable, ozone is highly reactive because that third oxygen atom is loosely bonded. This makes ozone an extremely effective oxidizer, meaning it reacts readily with other molecules, especially those that cause odours, bacteria, viruses, and mould spores.

The Ozone Generation Process

Most commercial ozone machines use a process called corona discharge to produce ozone. Here's a simple breakdown:

Air intake: The machine pulls in ambient air, which contains oxygen (O₂).
Electrical charge: A high-voltage electrical field is created within the machine, which splits some of the O₂ molecules into individual oxygen atoms.
Ozone formation: These single oxygen atoms then bond with other O₂ molecules to form ozone (O₃).
Ozone dispersal: A fan circulates the ozone throughout the treatment area, where it interacts with airborne and surface-level contaminants.

How Ozone Neutralizes Contaminants

Once released into the environment, ozone molecules begin to seek out and react with organic and inorganic compounds in the air and on surfaces. This reaction is called oxidation. When ozone encounters bacteria, viruses, odour molecules, or mould spores, it damages their cellular structure or breaks down their chemical bonds, effectively destroying them or rendering them inactive.

Odours: Ozone breaks apart the molecular chains responsible for foul smells (such as smoke, pet urine, or decay).
Bacteria & Viruses: Ozone attacks the cell walls or viral capsids, leading to inactivation or cell death.
Mould Spores: While ozone can destroy spores, it is not a replacement for physical removal. It’s used after remediation to address any remaining airborne spores or odours.

A Visual Analogy: Ozone as a Pac-Man for Contaminants

Imagine ozone molecules as tiny “Pac-Men” with an extra oxygen atom as their power-up. They roam the space looking for unstable, smelly, or harmful molecules to bond with. Once they find a target, like a smoke odour or a spore, they latch onto it and "consume" it through oxidation. In the process, the ozone molecule breaks apart and reverts back to regular oxygen (O₂), leaving behind cleaner air.

Because of this temporary and reactive nature, ozone does not leave behind chemical residues. However, it must be used responsibly, as high concentrations can be harmful to humans, animals, and sensitive materials if not handled properly. That’s why ozone treatments are only conducted in unoccupied areas by trained professionals following strict safety protocols.

When and Why We Use Ozone Machines

At Relief Restorations, we use ozone machines as a final step in many remediation and restoration projects. Their ability to reach deep into porous materials and neutralize odours at a molecular level makes them especially valuable in environments affected by fire, mould, water damage, or biological contamination. However, it's important to note that ozone is not a stand-alone solution, it is most effective when used in combination with proper cleaning, removal, and containment protocols.

Here are the most common scenarios where ozone treatment plays a crucial role:

After Fire or Smoke Damage: Smoke odour is notoriously difficult to remove because it penetrates fabrics, drywall, insulation, and other porous materials. Even after visible soot is cleaned, the smell can linger for weeks or months. Ozone treatment is used after all fire-damaged materials have been removed and cleaned to break down smoke particles and eliminate combustion odours from the air and structure.

After Mould Remediation: Once mould-affected materials have been removed and the area has been cleaned, dried, and treated, ozone can help with two things: neutralizing any remaining odour and targeting airborne microbial contaminants that may still be present. It is never used as a replacement for proper mould remediation, but as an additional safeguard and odour control measure after physical removal is complete.

After Water Damage or Sewage Backups: Standing water, saturated materials, and sewage create strong organic odours and increase the risk of microbial growth. After the affected areas have been dried, cleaned, and disinfected, ozone machines can be used to help eliminate lingering smells and reduce the microbial load in the air. This is especially important in crawlspaces, basements, or hard-to-access areas.

In Hoarding or Trauma Cleanup Situations: Hoarding scenarios and trauma or unattended death cleanups often involve complex odours from decomposition, bodily fluids, waste, or years of contamination. These biological odours are difficult to treat using standard cleaning methods alone. Ozone gas can penetrate deeply into materials and surfaces, helping to neutralize bio-odours and sanitize the environment post-cleanup.

General Odour Removal: Even in less extreme situations, ozone is highly effective at removing tough odours such as:

Pet urine and dander
Cigarette and cannabis smoke
Gasoline
Cooking grease and strong food smells (like fish, curry, or burnt food)
Musty basement or storage odours

In these cases, ozone is often used as part of a broader indoor air quality improvement plan, especially when selling a home or preparing a property for new tenants.

In all scenarios, our team ensures the space is completely unoccupied during treatment and that re-entry guidelines are clearly communicated to ensure safety and effectiveness.

Safety Considerations and Limitations

While ozone machines are highly effective in removing odours and reducing airborne contaminants, they must be used with caution. Ozone is a strong oxidizer, this same property that allows it to destroy odour-causing molecules also means it can pose risks to human health and sensitive materials if not managed properly. At Relief Restorations, we follow strict safety protocols to ensure each ozone treatment is both effective and safe.

Why Ozone Machines Must Only Be Used in Unoccupied Spaces

Ozone is harmful to breathe. At high concentrations, it can irritate the lungs, eyes, and throat, and may trigger respiratory issues, especially for individuals with asthma or other sensitivities. For this reason, ozone machines must only be operated in unoccupied spaces. This includes not just people, but also pets, plants, and fish tanks.

Before ozone treatment begins, we ensure that the property is completely cleared of occupants and that warning signage is posted. Doors are sealed, and entry is restricted for the duration of the treatment.

Ventilation Requirements After Treatment

Once the ozone cycle is complete, the space must be thoroughly ventilated before anyone can safely re-enter. Ozone naturally breaks down and reverts back to oxygen (O₂) over time, but the process can be accelerated by increasing airflow through fans, opening windows, or using HVAC systems where appropriate.

Our team will advise you on the appropriate ventilation steps based on the size of the space and the level of ozone used during treatment. In most cases, ventilation is initiated immediately after the machine shuts off.

Timeframes for Safe Re-Entry

Safe re-entry times vary depending on the size of the space, the strength of the ozone treatment, and ventilation conditions. As a general guideline:

Small rooms may be safe to re-enter within 1–3 hours after ventilation begins
Larger spaces or high-intensity treatments may require 4–8 hours or longer
A minimum waiting period of 30 minutes to 1 hour should always pass after ozone generation ends, even with ventilation

Our technicians will provide clear instructions based on the specific treatment plan and conduct air checks if needed to confirm the area is safe.

Ozone Is a Strong Oxidizer: Effective, But Must Be Handled with Care

Due to its oxidative strength, ozone can also degrade certain materials over time if used improperly. Prolonged exposure may cause damage to rubber seals, natural fibres, electrical components, and some metals or finishes. This is why ozone is used selectively and never as a routine or casual deodorising method.

At Relief Restorations, we assess every site to determine whether ozone is the right tool for the job. It’s never a first resort, but when needed, it’s a powerful and effective option in the hands of trained professionals who understand its risks and benefits.

Ozone treatment is not a DIY solution. It requires experience, precision, and clear protocols to ensure safety for both occupants and property.

Alternatives to Ozone and When to Avoid It

While ozone machines are highly effective for certain restoration situations, they are not always the most appropriate tool. Depending on the type of damage, materials involved, and whether the space is occupied, there are alternative odour and contaminant control methods that may be safer or more suitable.

Alternative Odour and Air Purification Methods

Several proven technologies can be used in place of, or in combination with ozone treatment:

Activated Carbon Filtration: HEPA air scrubbers fitted with activated carbon filters are highly effective at trapping odour molecules and volatile organic compounds (VOCs). These systems are safe for use in occupied spaces and are a common part of air purification during and after remediation projects.
Fogging (Thermal or ULV Fogging): Fogging disperses a fine mist of deodorizing or disinfecting solution throughout a space. This method is useful for addressing general odours and microbial issues but must be used carefully to avoid over-saturation of contents and materials. Depending on the product used, re-entry times are often much shorter than with ozone.
Hydroxyl Generators: Hydroxyl machines use UV light and water vapour to create hydroxyl radicals, which neutralize odours and contaminants in a way similar to ozone, but with one major benefit: they are safe for use in occupied spaces. While they take longer to achieve the same results, they are gentle on materials and preferred when the area cannot be vacated for extended periods.

When Ozone Might Be Too Harsh or Not the Best Option

There are several situations where ozone treatment may not be appropriate:

Occupied Properties: If people, pets, or plants must remain in the space, ozone is not a safe option. In these cases, hydroxyl generators or carbon-filtered air scrubbers are better choices.
Delicate Materials or Electronics: Prolonged exposure to ozone can degrade certain rubber seals, fabrics, artwork, and some electrical components. If these materials are present and cannot be removed, a gentler treatment method should be considered.
Light Odour or Surface Contamination: For mild odours or localized issues, simpler solutions like manual cleaning, spot fogging, or filtration may resolve the problem without needing a full ozone treatment.

The Importance of Assessing Each Job Site Individually

No two restoration projects are alike. The decision to use ozone, or any other deodorization method, should be based on a professional assessment of the space, the source and severity of the odour, occupant health and safety needs, and the materials involved.

At Relief Restorations, we conduct thorough site evaluations before recommending ozone treatment. In many cases, we combine multiple technologies to provide the safest and most effective outcome for our clients. Our priority is always to restore healthy air quality without compromising safety or property condition.

How Relief Restorations Uses Ozone Machines Safely and Effectively for Ozone Odour Removal and Disinfection

At Relief Restorations, safety and precision are at the core of every ozone treatment we perform. Because ozone is a powerful tool with potential risks, we follow strict protocols to ensure it is used only in appropriate situations and always under controlled conditions. Our team is fully trained in the safe operation of ozone machines, and we tailor every deployment to the specific needs of the space, the severity of the odour, and the materials present.

Our Safety Protocols

Before any ozone treatment begins, we implement a series of safety measures to protect our team, our clients, and the property:

Confirm that the space is fully unoccupied: no people, pets, or plants may remain inside
Post clear warning signage at all entry points
Seal off treatment areas as needed to contain ozone within the affected space
Pre-plan ventilation strategies to allow for rapid and safe re-entry once treatment ends
Monitor ozone exposure time to avoid over-treatment and material degradation
Ensure our technicians use proper PPE when entering the area post-treatment for air quality verification

Step-by-Step of a Typical Ozone Deployment

Site Assessment: We evaluate the odour source, materials affected, and environmental conditions to determine if ozone is the right tool. Alternatives may be recommended depending on the findings.
Preparation and Containment: We remove sensitive contents when needed, seal HVAC vents, and close off the area to contain the ozone. Occupants are instructed to vacate the property for the required duration.
Machine Placement and Timer Setup: Ozone machines are strategically placed in the space and set on a timer based on the volume of air, level of contamination, and manufacturer guidelines.
Treatment Phase: The machine runs until the programmed cycle ends. During this period, the space remains sealed and off-limits.
Ventilation Phase: Once treatment is complete, we initiate cross-ventilation using fans and open windows or doors to rapidly disperse any remaining ozone.
Final Inspection: Our team conducts a post-treatment check to ensure the air is safe, odours have been neutralized, and no sensitive materials were affected.

Emphasis on Training, Containment, and Post-Treatment Checks

All ozone treatments at Relief Restorations are carried out by trained professionals who understand the chemical behaviour of ozone and its interaction with different surfaces. We never take a one-size-fits-all approach. Every project includes detailed containment procedures, proper signage, and clear communication with the client regarding re-entry times and safety protocols.

Following treatment, we inspect the area to ensure results have been achieved and air quality is within safe levels before the space is reoccupied.

Combining Ozone with Other Remediation Strategies

Ozone is rarely used on its own. In many projects, it forms part of a broader indoor air remediation plan that may include:

HEPA air scrubbers with activated carbon filters to remove particulates and VOCs
ULV or thermal fogging to target specific odours in localized areas
Manual cleaning and disinfecting of surfaces prior to air treatment
Dehumidification and moisture control following water damage to prevent odour recurrence

By integrating ozone into a well-rounded treatment plan, we can address the root cause of odours while ensuring long-lasting, safe, and effective results for our clients.

Final Thoughts: Is Ozone Right for Your Restoration Project?

Ozone machines can be an incredibly powerful tool when used correctly and under the right conditions. Whether you're dealing with the aftermath of fire damage, a challenging mould remediation project, water damage odours, or biohazard cleanup, ozone treatment may offer the level of deep odour neutralization and air purification that traditional methods can’t always achieve on their own.

That said, ozone is not a one-size-fits-all solution. Because it is a strong oxidizer and must be used in unoccupied spaces, professional assessment is critical. At Relief Restorations, we evaluate each job site individually to determine whether ozone is the most appropriate and effective treatment, factoring in the nature of the damage, material sensitivities, occupant safety, and long-term results.

If you’re unsure whether ozone treatment is right for your home or building, we’re here to help. Our team is happy to provide a consultation, inspect your space, and recommend a tailored solution, whether that involves ozone, filtration, fogging, or a combination of strategies.

Contact Relief Restorations today to schedule an assessment or request a quote. Let us help you restore clean, healthy air, safely and effectively.

Need odour removal after a flood, fire, or mould issue? Relief Restorations offers expert ozone treatment services that are safe, effective, and tailored to your specific situation. Whether you're dealing with persistent smoke odours, post-mould mustiness, or water damage-related smells, our trained team is here to help restore clean, breathable air to your home or business.

We proudly serve Winnipeg and surrounding areas, providing professional restoration and air quality services you can trust.

Let us help you breathe easier, safely and professionally.

Contact Relief Restorations Today – Schedule a mould air test, moisture survey, asbestos testing, inspection or consultation with our team to ensure your home is protected. Let us help you safeguard your home and restore peace of mind, knowing that you’re in good hands.

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About Relief Restorations

At Relief Restorations, we specialize in providing comprehensive mould remediation, water damage restoration, asbestos removal, light demolition, inspection and testing services across Winnipeg and Manitoba, Canada.

With a focus on safety and quality, our expert team is dedicated to restoring your property and ensuring a healthier living environment. Whether you're a homeowner, business, tenant, landlord, or property manager, you can trust us to handle any restoration or remediation challenge with professionalism and care. Contact us today to learn more about how we can help protect your property.

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