If you’ve started looking at chemical-free cleaning, you’ll quickly find that there isn’t just one approach.
Some systems generate ozone. Others use salt and electrolysis. Some produce a solution that needs to be used relatively quickly, while others are designed to keep the solution active for longer.
For a busy facilities or cleaning team, these differences matter. They affect what you need to buy, store and maintain, how your team uses the system and what it costs to run.
So, what are the main options and what should you look at before choosing one?
What do we mean by “chemical-free” cleaning?
It’s worth clearing this up first.
When people talk about chemical-free cleaning, they are generally talking about reducing or removing the need for conventional cleaning chemicals from the cleaning process.
It doesn’t mean there is no chemistry involved. Water itself is a chemical, and systems such as electrolysed water deliberately create active chemical compounds as part of the process.
For a facilities team, the more useful question is:
Can we clean effectively without buying, storing, mixing and disposing of multiple conventional cleaning chemicals?
That’s where the different technologies come in.
The options at a glance
Three on-site generated solutions are particularly relevant to general commercial cleaning:
- Natural Aqueous Ozone (NAO), generated from oxygen, water and electricity
- Stabilised Aqueous Ozone (SAO), which uses an additional stabilising or water-treatment stage
- Electrolysed Water, which uses salt, water and electricity to generate an active cleaning or sanitising solution
They may all be used to reduce reliance on conventional cleaning chemicals, but they work in different ways.
| Natural Aqueous Ozone (NAO) | Stabilised Aqueous Ozone (SAO) | Electrolysed Water | |
|---|---|---|---|
| What it’s made from | Cold mains water, oxygen and electricity | Cold tap water and a specialised filtration and electrical infusion system | Water, salt or brine and electricity |
| Made on site? | Yes | Yes | Yes |
| Ongoing consumables | N/A | A cartridge/filter which is replaced every 3 months | Salt or brine supply every month |
| How long does it last? | Lasts up to 4 hours as a sanitiser, or up to 8 hours as a general cleaner. | Depending on the cartridge, the solution can last 4 hours as a sanitiser, or up to 6 days as a general cleaner. | Depends on the system and solution produced, however, it typically lasts between 7 and 14 days. |
| What happens after use? | Aqueous ozone naturally breaks down into water and oxygen after it finishes cleaning | Aqueous ozone naturally breaks down into water and oxygen after it finishes cleaning | Electrolysed water naturally breaks down back into ordinary salt and water after it finishes cleaning |
| Main thing to consider | There are very minimal ongoing costs. | Replacement cartridges are required every 3 months. | Salt supply is required every month, depending on usage. |
The exact specification varies between systems, so it’s important to look at the individual unit rather than assuming every system using the same technology works in the same way.
Natural Aqueous Ozone (NAO)
Aqueous ozone is a cleaning and sanitising solution derived from a naturally occurring process.
In nature, ozone (O₃) forms when oxygen molecules (O₂) are split by lightning, creating oxygen atoms (O) that bond with other oxygen molecules. This process produces ozone, a highly reactive and powerful oxidiser.
When ozone is dissolved in water, it creates aqueous ozone, a solution that combines ozone’s antimicrobial properties with water’s versatility.
This process is replicated using technology that generates ozone by applying an electrical charge to oxygen and infuses it into water. The result is natural aqueous ozone, a safe, efficient, and eco-friendly cleaning solution that can be dispensed into spray bottles, buckets or cleaning equipment and used as part of a routine cleaning process.
What are the benefits of NAO?
For a commercial cleaning team, one of the main attractions of NAO is the simplicity of producing the solution on site, when it is needed.
Because there is no stabilising cartridge, there are no ongoing cartridge replacement costs and no plastic waste from discarded cartridges. The solution is generated on demand using the resources already available on site, rather than relying on a consumable cartridge to keep the ozone active.
This can make NAO less expensive to produce over time than a SAO system, particularly when you consider the ongoing cost and waste associated with replacement cartridges.
For cleaning teams, there are also practical benefits. There is no need to order, store or remember to replace stabilising cartridges, and reusable bottles can be filled directly from the unit.
The aqueous ozone naturally breaks down into water and oxygen, so the solution does not leave behind a conventional chemical residue. Once its effective working period has passed, it continues to return to its natural state.
Aqueous ozone also uses nanobubble technology to help distribute the ozone through the water and support the stability of the solution during use.
There is another environmental consideration too. By generating the solution on site, aqueous ozone can reduce the need for deliveries and single-use packaging associated with conventional ready-to-use cleaning chemicals.
Ozoklenz NAO solution has been tested to EN 1276 and EN 14476.
Questions to ask about NAO
If you’re considering a NAO system, it’s worth asking:
- How long does the solution remain effective?
- How much solution can the unit produce?
- What maintenance is required?
- What surfaces and applications is it suitable for?
Stabilised Aqueous Ozone (SAO)
Stabilised aqueous ozone works on the same basic principle: ozone is dissolved into water.
The difference is that the system includes an additional water-treatment or stabilising stage designed to help the ozone remain active for longer.
This can be useful for sites where cleaning teams need to prepare a solution in advance or use the same solution over a longer period.
The trade-off is that stabilised systems require an additional consumable, such as a cartridge or filter, which needs to be replaced according to the manufacturer’s instructions (typically every 3 months).
That doesn’t necessarily make one system better than the other. It comes down to how the solution fits into the way your cleaning team works.
For example, a longer-lasting solution may be useful if teams need to prepare bottles ahead of a shift. On the other hand, if a team is happy to generate fresh solution as part of its daily routine, avoiding a cartridge can make the process simpler.
Questions to ask about SAO
If you’re considering a SAO, it’s worth asking:
- How long does the solution remain effective?
- How often does the cartridge need replacing?
- What does a replacement cartridge cost?
- What happens when the cartridge reaches the end of its life?
- What maintenance is required?
- What surfaces and applications is it suitable for?
Looking at the ongoing cost is important. The initial equipment cost only tells you part of the story.
Electrolysed water
Electrolysed water is another established way of producing a cleaning or sanitising solution on site.
Instead of generating ozone, the system passes an electrical current through water containing salt or brine. Depending on the system, this produces an active solution containing hypochlorous acid and other chlorine-based species.
The chemistry is therefore quite different from aqueous ozone.
Electrolysed water can provide effective antimicrobial activity, but the performance of the solution depends on factors such as its free available chlorine concentration and pH. These need to be controlled to produce a consistent solution.
There are also different types of electrolysed water systems, so it’s important to understand exactly what a particular machine produces and how it should be used.
What should you consider with electrolysed water?
If you’re considering an electrolysed water system, it’s worth asking:
- How much salt or brine does the system use?
- How is the concentration checked?
- How is the pH monitored?
- How long does the solution remain effective?
- Does the system require regular cleaning or maintenance?
- What happens to the solution after use?
- What testing is available for the intended cleaning or sanitising application?
Every system has its own requirements, and these should be understood before installation.
How do the three options compare?
There isn’t a single system that is automatically right for every site.
The biggest difference is how each solution is generated and its ongoing costs.
NAO is generated on demand whenever required. With Ozoklenz, there is no stabilising cartridge, and the solution naturally breaks down into water and oxygen after it has finished cleaning.
SAO uses an additional stabilising or water-treatment stage to extend the active life of the solution. This can make sense for teams that need to prepare solution in advance, but introduces the ongoing cost and plastic waste of a replacement cartridge or filter.
Electrolysed water uses salt, water and electricity to create an active solution. It can be useful where the chemistry and operating requirements suit the cleaning programme, but it requires consideration of salt supply, concentration, pH and maintenance.
What should you ask before choosing a system?
1. Are there any ongoing costs?
Look beyond the initial cost of installing the system.
Consider cartridges, salt, filters, replacement parts, maintenance, servicing and any other consumables.
Ask for the expected running cost over a year, not just the purchase price.
2. How long does the solution remain effective?
This can have a big impact on the cleaning routine.
Neither approach is automatically better. It depends on the site.
3. What surfaces is the solution suitable to clean?
Ask the supplier for a clear list of:
- surfaces it is suitable for
- cleaning applications
- sanitising or disinfecting applications
- required contact times
- any situations where another product or process is still needed
4. What certifications does the solution have?
This is one of the most important questions to ask.
Look for laboratory testing. For example, EN 1276 and EN 14476
5. What does the cleaning team need to do?
Consider:
- How is the solution generated?
- How are bottles and buckets filled?
- Does anything need to be mixed?
- How is the solution stored?
- What happens to unused solution?
- What training is required?
- Who is responsible for maintenance?
6. What happens if something goes wrong?
Ask about servicing and support before you install anything.
Who do you contact if the unit stops working?
How quickly can someone help?
Are spare parts available?
These questions become particularly important if you’re rolling the system out across multiple buildings or a large estate.
Chemical-free cleaning isn’t one-size-fits-all.
There are several ways for facilities teams to reduce their reliance on conventional cleaning chemicals, but the right solution depends on how each site operates.
NAO, SAO and electrolysed water all have their own advantages and considerations.
Frequently asked questions
Is Natural Aqueous Ozone (NAO) the same as Stabilised Aqueous Ozone (SAO)?
Both use ozone dissolved in water, but the difference is in the way the ozone is generated.
NAO generates aqueous ozone on demand without a stabilising cartridge. SAO systems use an additional water-treatment or stabilising stage to extend the working life of the solution.
Is electrolysed water the same as aqueous ozone?
No.
Aqueous ozone uses ozone generated from oxygen and dissolved into water.
Electrolysed water uses an electrical current and salt or brine to generate an active solution containing hypochlorous acid and other chlorine-based species.
Are there any ongoing costs with Ozoklenz?
No. Ozoklenz generates a natural aqueous ozone solution, so there are no stabilising cartridges to replace. Ozoklenz uses cold mains water and electricity to generate aqueous ozone on demand.
As with any equipment, there are routine maintenance requirements, so these should be discussed when selecting and installing a unit.
Can chemical-free cleaning replace every cleaning product?
Not necessarily.
The aim should be to reduce conventional chemical use where an alternative is suitable, rather than assuming one solution will cover every application.
It cannot completely replace targeted, heavy-duty deep cleaning products such as heavy limescale removal or oven degreasing.
Which chemical-free cleaning system is right for my site?
That depends on your buildings, cleaning routines, surfaces and what you’re trying to achieve.
At Ozoklenz, we prefer to understand how your cleaning team works and look at where aqueous ozone could fit, rather than suggesting the same product for every site.
Considering a move towards chemical-free cleaning?
Speak to the team, and we’ll talk through your current cleaning process and where Ozoklenz could fit.