Farm hack: Use a hose end sprayer to quickly sanitize surfaces

 Annalisa Hultberg, Extension Educator, food safety

One of the most important (yet least exciting) parts of managing a farm is the cleaning and sanitizing of totes, tools, and equipment to keep your produce safe and long-lasting. As I have been visiting farms this summer, one of the more common issues farms are encountering is developing systems for larger sanitizing jobs, like sanitizing tables, many totes, or pieces of equipment. For these jobs, consider using a hose-end sprayer to apply surface sanitizer. 

Why do I need to sanitize surfaces?

Sanitizing reduces the contamination level on surfaces by killing  microorganisms that cause disease. Applying sanitizer does not mean that the surface will be totally free of microorganisms, but they will be greatly reduced. If done correctly, this process results in safer products and improved postharvest quality. It can also kill plant pathogens that can spread on surfaces and tools. 

Before you sanitize a surface you must clean it. Here are the cleaning steps: 

1.) Remove visible soil with water or a brush

2.) Scrub the surface with detergent (like Dawn) and potable water

3.) Rinse again with potable water to remove all the detergent

Applying the sanitizer

Next, apply a sanitizer approved for food contact surfaces. This might be food-grade bleach (unscented and not thickened) or SaniDate 5.0 or other PAA-based sanitizers. Consider using a hose-end sprayer to apply the sanitizer, especially if you are applying the sanitizer to a lot of totes or large surfaces. 

Read more about finding a sanitizer here. 

Steps to use a hose-end sprayer to apply surface sanitizer:

First, fill the sprayer reservoir with the sanitizer. Here, we are using SaniDate 5.0 from Biosafe. Next, turn the valve to 2 teaspoons per gallon, which is the rate to sanitize food contact surfaces. Make sure that the internal siphon is set to teaspoon, not tablespoon. You might have to insert the small plug inside the siphon straw to make it set to teaspoon per gallon.

Next, run the hose for a few minutes. Then fill a container with some solution to test for concentration. Make sure you use the tester strips made for the sanitizer you are using. We are using the PAA tester strips in the 1-160 range.

Next, make sure the concentration is appropriate. SaniDate 5.0 has a labeled rate of about 150 PPM for food contact surfaces. If the strip turns black very quickly, it is likely too high. You might need to reset the sprayer. 

You can now use the sprayer to sanitize surfaces after cleaning, like totes, tables, brush washers, drains, and cooler walls. Remember: Always wear the correct PPE when using these chemicals! SaniDate 5.0 is OMRI listed and approved and is made of vinegar, hydrogen peroxide and water and breaks down in the environment, but at full concentration it can be very dangerous to skin and eyes. Wear goggles, gloves and an apron when dispensing it at full concentration. 

Another tip - rinse the hose end sprayer with water frequently. The container will corrode. And recheck and calibrate often. If it seems too high, the internal teaspoon dispenser may have become dislodged. You should not apply PPM over 160 PPM, as per the label. 

You might be using a different surface sanitizer on your farm. Make sure to read the label and understand what rate the sanitizer needs to be applied at, and adjust the dispenser valve accordingly.