Preventing Listeriosis – Recommended Cleaning Procedures by the USDA

Jun 25, 2015 Food Grade Seals | Gaskets | FDA O-Rings

Listeriosis is developing into a problematic disease in the United States. The growth and spread of this disease is being observed by the Center for Disease Control and Prevention (CDC). In January 2015, Bidart Bros., a food and beverage company that supplies Granny Smith and Gala apples, recalled its entire apple inventory. Testing revealed that the apples were contaminated with listeria. A total of 35 people from 12 states were infected with the bacteria. Out of the total number, 34 patients were hospitalized, and three people succumbed to the disease.

What is Listeriosis?

For the US Department of Agriculture (USDA), and the US Food and Drug Administration (FDA), Listeriosis is a high priority disease. Listeriosis is an infection created by the bacteria Listeria. The infection can contaminate processed as well as unprocessed food. Listeriosis affects the central nervous system, and can cause meningitis, cerebritis brain abscess, and meningoencephalitis.

USDA Recommended Procedures for Preventing Listeria

Among the many types of food products sold, dairy products like milk, cheese, and curds are particularly susceptible to listeria. As milk is a vital drink for children and adults, even a small contamination may result in an epidemic. This can lead to lost lives, massive product recall, as well as thousands of dollars wasted. For these reasons, the USDA recommends certain procedures to F&B industries, and industrial seal manufacturers to prevent this problem.

Pipeline Gaskets

Pipelines consist of rubber gaskets. If unfit seals are used in the pipeline connection, it can result in milk leakage, which will lead to contamination. The USDA recommends replacing rubber gaskets at least once every three or four months. The Department also recommends:

Manually wash the interiors of the pipeline.
Concentrate on all seals, valves, and ferrules-cleaning and replacing.
Inspect all new gaskets to ensure that fittings are tight, and will not cause leakage.
Use sterilized gaskets during reassembly.

Milk Pumps

Pump seals are generally used to support the function of milk pumps. If the pump seal is ineffective, milk can leak from the seal, leading to contamination of pasteurized milk. For this issue, the USDA recommends that:

The pumps need to be disassembled and cleaned on a daily basis.
Any leaks, cracks, or other defects should be repaired on an immediate basis.
The seals should be inspected during the regular maintenance cycles, and replaced if any defect is found.

Filler Valves

Milk pump valves also comprise fillers. These fillers are verified using Cleaning in Place processes (CIP). The following steps are recommended for fillers that have not undergone the procedure:

Once the daily milk processing cycles have been completed, the filler valves and pistons need to be completely disassembled.
Every component needs to undergo the following:
- Rinsing with warm water
- Brush washing via manual cleaning
- Final wash using a circulation COP tank
Once the above steps have been completed, conduct a thorough inspection of all gaskets, O-rings, and rubber components.
Ensure that the above mentioned components are replaced if any sign of degradation is detected.

Paper Fillers

Unless paper fillers have been verified using CIP procedures, they need to undergo the following steps:

Disassemble all filler valves, and inspect any removable part. This includes pistons, bowl floats, and rubber check valves.
Use an industrial grade cleaning detergent solution, and manually rinse and brush wash the parts.
For further sanitization, the components can be immersed in tanks for CIP recirculation cleaning.
Fill valve screens need to be removed, boiled, autoclaved, and sanitized before reassembly.
Filler bowls can be washed separately:
- They can be set up for CIP pre-rinsing and washing procedures.
- The bowls need to be washed manually by applying a detergent solution to the inside of the bowl.
Lid gaskets should be manually cleaned on a daily basis.
Clean all pipe and probe openings either with manual or CIP cleaning procedures. Pay attention to vents and screens.
Mandrels should be cleaned with a foaming detergent, and a scouring pad or brush. Properly clean all the exterior surfaces, and then rinse with clear water.

Hygiene is an essential factor in food and dairy product processing. Improper processing of materials can result in products being affected by diseases like Listeriosis. Efficient cleaning and replacing as well as using FDA seals, gaskets, and O-rings can help avoid such problems in the future.