Cleaning and disinfecting are critical parts of all biosecurity programs. The goal is not to completely sterilize the environment, but rather to decrease the pathogen load significantly to a point where disease transmission does not occur.

There are many important steps to any cleaning and disinfecting process. Those steps and some important concepts will be identified here.

Cleaning and disinfecting are included in the National Pork Board's Pork Quality Assurance Plus and the Trucker Quality Assurance programs.

Cleaning and Disinfecting

To maximize the effectiveness of cleaning and disinfecting, focus on these four steps:

1. Cleaning. The first step is to remove all organic material. This is best achieved using a broom, shovel or scraper. Remove as much solids as possible to minimize the use of water in the next step.

In a farrowing house, this step is easy to do (except for emptying the sow feeders). On the other hand, when cleaning a semi trailer, the removal of wood chips or other bedding material takes significant time. Time spent properly doing this step will decrease the overall time of the process.

2. Washing. This step is the most time-consuming of the entire process, but it is also the most important. When done correctly, washing will remove 99.99% of the microorganisms in the environment.

The objective here is to remove all remaining organic matter (manure, feed, urine, etc). This is usually done with a high-pressure washer. There are two important numbers to look at when comparing equipment: pressure (pounds per square inch = psi) and how much water is being moved (gallons per minute = gpm). To calculate the effective cleaning units (or ecu), multiply the psi by the gpm (ecu = psi × gpm).

For example, a machine that delivers 4 gpm of water at 2,000 psi is considered to have 8,000 ecu (2,000 × 4.0 = 8,000), which would be comparable to a 2,500-psi machine delivering 3.2 gpm (2,500 × 3.2 = 8,000).

However, using too high of pressure, more than 3,000 psi, can cause problems. This rate of pressure can cause damage to surfaces or even cause organic matter to be displaced at high speeds, which can be dangerous to personnel.

As a general rule, 9,000 ecu are usually needed to strip paint off a wall.

The speed of cleaning will be dependent on the volume of water used. A psi of more than 2,000 is usually sufficient to do the job. A 4-gpm machine will remove manure twice as fast as a 2-gpm unit.

Besides having a good power washer, there are several other steps to facilitate this washing process.

• Soaking — Soaking surfaces before washing will cut down on the amount of time needed to do a more complete job. Soaking can be achieved by placing a sprinkler system in the rooms to be washed. When soaking a trailer, you may want to just wet the entire trailer first with a moderate amount of water, then start thorough washing at one end while other surfaces have more time to soak.

• Detergents — Another excellent way to maximize cleaning and minimize time spent on the chore is to use special detergents to help break down manure and other organic matter. This is the equivalent of using soap to wash your hands. You can wash your hands with plain water, but it is much quicker to use soap.

  Detergents are products used to reduce surface tension and suspend particles to facilitate cleaning. They can be acidic (good for protein removal) or alkaline (good for fats). Some commercial products contain both types.

  Many operations forget the value of detergents, mainly because of the added expense. In reality, most products are worth the investment not only because they cut down on labor, but also because they maximize the cleaning process and can break down bacterial biofilms (slime), which can harbor bacteria.

• Hot water — Hot water can also speed up the washing process. The one disadvantage of hot water is that it can produce steam and hamper visibility, particularly in winter. The goal is to have the water hot enough to facilitate cleaning without putting employees at risk. You will not be able to have the water hot enough to kill bacteria or viruses, as these high temperatures would cause skin burns. Studies have shown that the money used to heat the water will be saved in reduced labor.

3. Disinfecting — This is a critical step in the cleaning process that requires some use of science. Unless surfaces are completely cleaned (none-to-minimal organic matter), disinfection will not be effective.

Disinfectants are defined as chemicals used to control, prevent or destroy microbes on inanimate objects or surfaces. Most disinfectants are inactivated when they come in contact with organic material. There is no disinfectant that will work for all situations.

Traditionally, disinfectants are selected based on preferences or price rather than on specific objectives. All disinfectants used in the United States must be approved by the Environmental Protection Agency (EPA). So it is very important to read the labels. The following will summarize the general characteristics of each of the different classes of disinfectants.

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