X-ray inspection systems used in food production are known as cabinet x-ray systems. These systems use x-ray generators instead of naturally occurring radioactive material. As a result, the system does not produce radiation unless electricity is flowing through the generator. The use of a generator also allows for emergency shutoff mechanisms that cut power when the cabinet is opened, preventing x-ray exposure to operators. In addition, cabinet systems automatically shut down the x-ray generator in the event of any error or stoppage of the system. All METTLER TOLEDO x-ray systems are equipped with a warning light tower to indicate when the x-ray generator is active, along with warning labels in the local language to help prevent misuse.

An additional radiation test is performed after installation to verify that no damage occurred during transport or installation. After installation, operators must follow the safety procedures that are in place. These procedures include:

• The correct method for removing products from the system in the event of a jam or conveyor malfunction
• The proper cleaning procedures
• Appropriate handling and removal of rejected products

They also include routine system maintenance, since keeping the system functioning properly is the best way to keep x-ray exposure as low as reasonably achievable.

Depending on local regulations, periodic or annual radiation surveys of the production site may also be required. Local radiation guidance and regulatory requirements vary by country, so operators should always follow the specific rules and procedures applicable in their location. This is an effective way to verify the safety of the system throughout its operational lifespan.

ALARA does not apply only to the use of x-ray inspection systems in production, it also applies to the manufacturing of the systems themselves. All handling of the components that make up an x-ray generator and system is carried out to minimize the risk of radiation exposure.

The most likely points of radiation leakage in an x-ray inspection system are where products enter and exit the system, areas where operators are not typically standing. In addition, operators are not likely to be near the system at all for most of their shifts. Combined with other reasonable safety measures, maximum exposure to radiation can remain well below 1 µSv/hour.

X-ray inspection systems are used to help keep consumers safe from foreign body contamination, and their construction and operating procedures are designed to help keep operators safe from radiation exposure. There is no way to avoid exposure entirely, but by keeping the risk of exposure as low as reasonably achievable, operators can continue their routines with confidence.

ALARA’s principles of risk reduction can be expanded into a general workplace health and safety philosophy. Instead of ALARA, or As Low As Reasonably Achievable, this becomes ALARM: As Low As Reasonably Manageable.

A contamination control plan has three goals: eliminate contamination, prevent contamination, and detect contamination if elimination and prevention fail. The first two goals, elimination and prevention, are process-based. By “processes,” we mean cleaning routines, line equipment such as magnets or sieves, and daily operating procedures. This also includes how frequently systems are cleaned, how employees are expected to dress, and the use of personal protective equipment (PPE) such as hairnets, masks, and gloves. It also includes system maintenance to prevent contamination caused by failing equipment, such as metal or plastic shavings.