​​Chemical sanitisers​

Chemical sanitisers are applied to food contact equipment after cleaning to kill bacteria that survive the cleaning process. A surface needs to be thoroughly cleaned before it is sanitised.

The Australia New Zealand Food Standards Code requires food businesses to ensure any equipment that comes into contact with food, such as kitchen benches, knives, chopping boards, eating and drinking utensils, pots, and meat slicers, is in a clean and sanitary condition.

To be effective in a food premises, a sanitiser should kill at least 99.99% of bacteria.

Types of chemical sanitisers

The most common chemical sanitisers are chlorine-based products, such as hypochlorite (also known as bleach), and quaternary ammonium products.  

Some sanitisers can be used as received spray and wipe activities without dilution, for example, spraying on benches. They’re not suitable for equipment that requires immersion (dipping).

Different brands of sanitiser vary greatly in how they are used. Clear instructions must be provided either on the product label or an accompanying information sheet.  

It is important to understand:

• Is it safe to use on food contact equipment?  
• Is it ready-to-use or does it require diluting?  
• If it requires dilution, what are the dilution rates?  
• What is the ‘contact time’ (the amount of time it must be in contact with an item for it to work)?  
• Is rinsing required?
• What is the shelf life of the concentrated and diluted product?

Applying chemical sanitisers

• Only use products with clear instructions and follow them.
• Thoroughly clean, and then rinse, the item before sanitising. Sanitisers are ineffective on surfaces with food and detergent residue.
• Make the sanitiser to the correct dilution rate (too low or too high is ineffective) and use the correct water temperature and contact time specified.
• Make a fresh batch every 24 hours (or as specified). The active chemical loses strength over time.
• Ensure sanitising spray bottles are labelled correctly, for example with the name of the product and when it was made up.
• Completely cover all surfaces to be sanitised with the sanitising solution using either immersion (dipping in a sink) or a spray.
• Pay special attention to difficult-to-get-to surfaces in equipment, such as stab mixers, blenders, meat slicers and can openers. Equipment may need to be dismantled (per manufacturer’s instructions). Equipment that cannot be effectively cleaned and sanitised should not be used in a food business.
• After sanitising, thoroughly dry. Wet surfaces pick up dirt or other contaminants more easily. Air drying is preferred, otherwise use clean, dry, single-use towels.  
• Take care not to re-contaminate sanitised items. They should be moved using clean hands and stored in a clean and sanitary place.

Using bleach

Businesses using bleach as a sanitiser must follow the dilution instructions in Table 1 below. Use only plain unscented bleach.

The contact time varies depending upon the product, concentration, water temperature and other factors (such as pH). A stronger concentration is required for cold water.

To be effective, bleach typically requires up to 30 seconds contact. It does not need to be rinsed off, as long as the dilution instructions were followed.

Table 1. Bleach dilution instructions

To calculate the amount of bleach required, simply multiply the appropriate bleach amount above by the number of litres in any given container.  

Examples

How much 4% chlorine bleach do I need to add to a 500ml bottle of cold water?

• If 1 litre of cold water requires 2.5 ml of bleach (at 4% chlorine)  
• 500ml = 0.5L  
• Therefore 2.5ml x 0.5 = 1.25ml  

How much 4% chlorine bleach do I need to add to a 7-litre bucket of cold water?  

• If 1 litre of cold water requires 2.5 ml of bleach (at 4% chlorine)
• Therefore 2.5ml x 7 = 17.5ml

More information

• Cleaning and sanitising in food businesses