Ozone Defined
Ozone is a gas that, when dissolved in water, kills pathogens and microorganisms, destroys organic contaminants, breaks down inorganic contaminants, kills biofilms, all by intense oxidation.
Ozone Facts
When dissolved in water (pH 7.4-7.6), ozone is at equilibrium: creating half ozone molecules and half hydroxyl radicals.
Ozone Facts and Fallacies
| Fallacy | Fact |
|---|---|
| Ozone is dangerous, corrosive and off-gasses | Ozone has been safely used in thousands of applications with no off-gas and no danger to humans or the environment with accepted management practices. |
| Ozone is cost-prohibitive or expensive | Ozone is very affordable and offers so many benefits. It is a natural, environmentally sound sanitizer to which no microorganisms can build an immunity, and adds no byproducts to the water |
| Ozone is an oxidizer only | Ozone is a highly efficacious sanitizer, disinfectant and purifier; these provided by its strong oxidation capabilities |
| Ozone is not as strong as traditional sanitizing chemicals | Ozone is exponentially stronger and more efficacious than all standard sanitizers (10-15,000 times greater) and very safe |
| Ozone is new technology | Ozone is an approved sanitizer that has been used in numerous applications since 1906 |
Ozone is an Approved Sanitizer
- Food contact surfaces, non-food contact surfaces & CIP/SIP
- Direct Food Contact and Bottled Water
- Pharmaceutical processes (CIP/SIP/surfaces/product water)
- Personal Care Product and Industrial sanitation processes
- Irrigation water, potable water and waste water
Ozone Properties
- Ozone is a gas produced at the point of use in a device called an ozone generator utilizing air or oxygen-enriched feed gas and electricity
- Oxygen molecules (O2) split with the addition of energy, resulting in two individual oxygen atoms (O1)
- Oxygen atoms (O1) unite with other oxygen molecules (O2) to produce Ozone (O3)
- (O1) + (O2) = (O3) as represented in the diagram
Ozone Oxidizing/Sanitizing Properties (Gaseous or Aqueous)
- The third oxygen atom is held by a weak single bond
- An oxidation reaction occurs upon any collision between an ozone molecule and a molecule of an oxidizable substance
- The weak bond splits off leaving oxygen as a by-product
- The third atom oxidizes the cell membrane, ultimately causing cell bursting (Lysing) and destruction
- This process can attain complete sanitation on surfaces (i.e. 6 log reduction – 99.9999%)
Electron Micrographs of E. coli
Before/After Ozone Treatment
Ozone Functionality
- Ozone is a strong oxidizer, disinfectant and sanitizer
- Ozone has a short half-life (seconds to minutes depending on temperature and pH if aqueous; minutes to hours in air), and reverts to oxygen
- Ozone is generated and applied on-site
- Ozone can be utilized as a gas or a fog (in a confined and controlled-access space) or it can be dissolved in water for targeted application
Ozone Benefits
- Ozone is an efficacious antimicrobial oxidizing agent, disinfectant, and sanitizer
- The disinfecting capability of 1 PPM Aqueous Ozone is equivalent to many times (10 to 4,000 times) the concentration of free available chlorine (Morris, 1975 – Disinfection: Water & Wastewater), depending on pH, temperature, and on the specific microorganism(s) to be destroyed
- Some microorganisms (oocysts such as Cryptosporidium parvum) are tolerant to chlorine but are destroyed by ozone
- Bacteria (and viruses) cannot develop a tolerance to ozone because disinfection occurs by the high oxidation power of ozone attacking cell walls/membranes (bacteria) or the DNA chains (viruses)
- Aqueous ozone is documented to effectively break down and remove biofilms of varying types
- Ozone (sometimes alone, sometimes combined with UV radiation or hydrogen peroxide) is documented to destroy pharmaceutical pollutants such as endocrine disruptors
Ozone is a Sustainable Technology
- Ozone is produced with ambient air and electricity in an apparatus (ozone generator) which utilizes very low energy
- There are no consumables utilized in an ozone generator
- Ozone is not stored, transported or discarded
- Its primary byproduct is natural oxygen, the same oxygen we breath to sustain life
- Microorganisms cannot build up a tolerance to ozone
- Ozone is an approved food and organic food additive
- Its use cannot harm the environment or eco system
- It is more efficacious than traditional sanitizing chemicals; reducing their use and disposal
- Ozone is used in cold water; resulting in energy savings
Ozone Innovative Applications
- Ozone can be applied as an aqueous product
- It can be hard-plumbed into existing sanitation lines as a centralized system
- It can be utilized with hand-held or fixed sprayers
- It can also be used as a flood or cascade
- Aqueous ozone is sprayed at low pressure (20 psi or less) in cold water (<70°F)
- Low-pressure use is designed to gently flood surfaces without causing pressurized over-spray that can inadvertently spread microorganisms to other areas of a facility.
- Gaseous ozone and ozone fog can be applied in controlled environments for microorganism control and spoilage reduction which results in increased shelf-life and increased yield.
- Gaseous ozone and ozone fog can be applied in controlled environments for microorganism control and spoilage reduction which results in increased shelf-life and increased yield.
Ozone Proven Technologies
- Ozone use will reduce levels of fat, oil & grease on surfaces, and it will break down microorganism and biofilm build-up on all surfaces
- Its continuous use will sanitize floor drains with no adverse effect on wastewater treatment systems
- Ozone helps to rid drains and plumbing of biofilm and other microorganisms that can migrate back into the processing area (esp. Listeria monocytogenes)
- Ozone is beneficial to sewage treatment systems because it adds dissolved oxygen to the wastewater to be treated
- Ozone sanitation sprays keep conveyor belts clean and free of build-up. “Build-up” may consist of food debris, sugar, fat, grease, etc., while harboring biofilm that may consist of any number of human pathogens, as well as fungi
Chlorine vs. Ozone – 11 Days Without Sanitation – Fruit Production Facility
Ozone Sanitizing in Industrial Applications
Other facilities utilizing ozone for various sanitation processes include:
- Pharmaceutical processing facilities
- High purity water for biotech processors
- High purity water for semiconductor producers
- Cosmetic and Personal Care product processors
- Process Water Recycling
- Municipal drinking water and wastewater treatment
- Anywhere wettable surfaces need to be sanitized.
Ozone Safety & Control
Ozone (Gaseous) Safety & Control
- OSHA PEL: 0.1 PPM 8 hour
- OSHA STEL: 0.3 PPM 15 min
Ozone (Aqueous) Safety & Control
- PEL: none established
- STEL: none established
- Eye Contact:: may cause mild irritation; not expected
- Ingestion Hazard: not ingested during application
- Inhalation Hazard: not likely; exposure to aerosolized aqueous ozone could become irritating
- Skin Contact: not hazardous
Aqueous ozone systems operated according to GMP, are safe for workers; these systems utilize monitor/control devices to continuously adjust operational parameters to ensure proper efficacy and safety.
If catastrophic leaks happen, air monitor set point is exceeded; monitors instantly cut off electricity flow to ozone generators stopping production of ozone.
Ozone Material Compatibility
Components & Piping
| Material | Ozone gas < 2500 ppm | Ozone gas > 2500 ppm |
| Glass | ||
| Ceramics | ||
| PVC | NR | |
| CPVC | NR | |
| UPVC (unplasticized) | NR | |
| Aluminum | (4% wt max) | |
| 304 L stainless steel | ||
| 316 L stainless steel | ||
| UPVC (unplasticized) | ||
| Superalloys Such as Inconel1 and Hastelloy-C2 | ||
| Titanium | ||
| Perfluoroalkoxy Resin (PFA) such as Teflon®3 or equivalent | ||
| Fluorinated ethylene propylene (FEP) such as Teflon®3 or equivalent | ||
| Polytetrafluoroethylene (PTFE) such as Teflon®3 or equivalent | ||
| Ethylene tetrafluoroethylene (ETFE) such as Tefzel®3 or equivalent | ||
| Ethylene chlorotrifluoroethylene (ECTFE) such as Halar®4 or equivalent | ||
| Neoprene® or equivalent | NR | |
| Polyvinylidene fluoride (PVDF) such as Kynar®5 or equivalent | ||
| P-chlorotrifluoroethylene P-CTFE such as Kel-F®6 2800 and Neoflon®7 or equivalent | ||
|
NOTE 1 — Abbreviations for components, piping, gasket and seals are in accordance with ASTM D4000. 1 Special Metals Corporation, 2 Haynes International, Inc., 3 Dupont, 4 Ausimont USA, Inc, 5 Elf Atochem North America, 6 3M Company, 7 Daikin Industries NOTE 2 — NR – not recommended |
||
Gaskets & Seals
| Material | Ozone gas < 2500 ppm | Ozone gas > 2500 ppm |
| p-chlorotrifluoroethylene (P-CTFE) such as Kel-F®1 or equivalent | ||
| perfluorelastomer such as Kalrez®2 or equivalent | ||
| perfluorinated copolymer such as Chem-Rez®3 or equivalent | ||
| Gortex® or equivalent | ||
| PTFE tape | ||
| chlorosulfonated polyethylene such as Hypalon®2 or equivalent | NR | |
| vinylidene fluoride such as Viton®2 or equivalent | (4% wt max) | |
| polydimethyl siloxane (silicone) | (4% wt max) | |
| ethylene propylene diene monomer (EPDM) | NR | |
|
1 3M Company 2 Dupont 3 Green, Tweed and Company NOTE — NR – not recommended |
||
Surfaces
| Material | Ozone gas < 2500 ppm | Ozone gas > 2500 ppm |
| Concrete, painted concrete | ||
| Rubber Modified Vinyl | NR | |
| Galvanized Steel | NR | |
| NOTE — NR – not recommended | ||
How is Ozone Measured
- Dissolved ozone is measured by an Oxidation Reduction Potential (ORP) monitor/controller, as well as an electronic dissolved ozone monitor/controller
- The ORP reading can range between 600 mV to 900 mV at the point of introduction into the main return line before entering the pool
- An ORP of 800 mV is ~ 0.2 PPM dissolved ozone which is estimated to equate to ~40 PPM Cl in terms of oxidation and antimicrobial efficacy
- An increase of 100-200 mV ORP over the Cl ORP is a significant increase in oxidation of contaminants
Understanding ORP (REDOX)
- ORP (Redox) stands for Oxidation Reduction Potential
- ORP measures the water’s cleanliness, the ability to break down contaminants, and the antimicrobial potential of the water
- Oxidation is measured by the ORP probe sending the signal in millivolts (mV)
- Positive ORP indicates the presence of an oxidizing agent
- Negative ORP indicates the presence of a reducing agent (severe impurity)
- In general, tap water has an ORP of about 200 mV
- Chlorinated tap water can be up to 600 mV
- Water with an ORP of 650 mV or greater will not harbor harmful pathogens