Getting Caught in the Vortexx -
Using Peracid Sanitizers

There has been a lot of interest lately from the goat milk community in the Ecolab product Vortexx, a sanitizer that contains a chemical called a "peracid" (also called "peracetic acid" or "peroxyacetic acid"). This product is designed to combat biofilms, and has been very effective in reducing the fluctuating bacteria counts recently experienced by some producers. However, Vortexx is not the answer to all milk quality problems and therefore needs some careful consideration before use.

Peracid is a synthetic chemical that is widely used in the meat and poultry processing industry as a sanitizer for food contact surfaces. It is a very strong oxidizer, what that means is that it can strip bacteria of its basic components, thereby killing them. Therefore the stronger the oxidizer, the more effectively bacteria are killed. Below is a table illustrating the oxidizing power of some common chemicals.

From NOSB TAP Review of Peracetic acid, compiled by OMRI, November 2000

Peracid can have a longer residual activity in the milkline than chlorine making it a more effective sanitizer. It eventually breaks down into water and oxygen so there is virtually no residue left in the line, little chance of contamination of product, or environmental impact. Peracids also work well at lower temperatures and pH (from acidic to neutral) and can also control minerals from depositing on the milkline.

Overall, peracids have shown to be extremely effective in situations where a biofilm may be present in the milkline. Manufacturers and distributors of Vortexx can supply you with detailed written instructions for its use. Follow them carefully to achieve best results.

So do you switch sanitizers and use peracid over chlorine? Peracid products should be used to replace the chlorine sanitizer only when a biofilm is suspected. It is recommended by Dr. Mansel Griffith at the University of Guelph that you "use peracid-based sanitizers for only two weeks to ensure biofilm removal…..then go back to your regular sanitizer routine" (Ontario Milk Producer, September 2002). If you suspect that a biofilm may be present in your milkline, which usually occurs when your bacteria counts fluctuate or "spike", and doubling your detergent and chlorine concentration or using a hot acid wash has had little effect, you may want to use a peracid product to combat the biofilm until counts settle. Rotating sanitizers in your cleaning regime may also be an option to consider, using chlorine as the regular sanitizer and then "shocking" the milkline with peracid once a month to help keep bacteria levels at bay. Vortexx is also more expensive than most chlorinated products, so using it only in the event of a suspected biofilm will help keep your cleaning costs down.

Do not fall into a false sense of security after using a peracid and achieving a low bacteria count that the problem has been resolved. If your counts start to rise or you notice a dull sheen to the inside of your pipes and bulk tank, use a peracid sanitizer as a preventive step against a possible biofilm from forming. Also do not take for granted that the milkline cleaning step is the only measure against poor milk quality. There may be other areas that are contributing to the bacteria levels in the milk, such as animal health, poor milking procedures, excessive dust in the environment during milking, or worn rubber parts like inflations and hoses. As with any sanitizer, the less contamination in the milk, the more effective the sanitizer will be, so maintaining good hygiene practices and equipment maintenance routines (refer to "Do I have a Biofilm?" in this issue) will help your cleaning regime be more effective and prevent your bulk tank from being rejected.

A producer spends so much time looking after the welfare of the goats they may dismiss their own personal safety. Peracid is an irritant to the eyes, skin and respiratory tract, and care should be taken when using this chemical or products containing peracid. Always protect yourself when working with any type of chemical, wear eye protection and gloves, and when pouring chemicals make sure the room is well ventilated. Most importantly, read the label on the product for proper handling and storage instructions.