Countries around the world have regulatory standards to ensure X-ray safety. These regulations are in place to make sure that the X-ray equipment can be used by technicians and operators in all possible conditions. Food processors need to make sure that their X-ray inspection machines are certified to these standards before installing systems in these regions. Some examples of key regulations by country are shown here.
Below are some of the most important design and manufacturing guidelines that should be followed stemming from these regulations:
- No more than 1.0 microsievert of radiation should escape from the system at a minimum distance of 5 cm and from the machine. Note the U.S. FDA limit is 5 microsieverts (.5 Mrem/hr) at 5 cm; the UK IRR 1999 is 1 microsievert at 10 cm, so this test is a worst case combination of the two standards. (See infographic Is X-ray Inspection of Packaged Food Safe?)
- To meet the radiation leakage standard, interior shielding should be used, such as stainless steel or lead.
- Multiple layers of radiation-blocking curtains should be used where products enter and exit the system.
- Access panels that require a tool to open and feature an electronic interlock; when a panel is opened for cleaning or maintenance, the X-ray source and conveyor should immediately shut off.
- When a conveyor belt is stopped to remove a jam, or if there is some other production issue, the X-ray must immediately turn off.
- An X-ray lockout key switch should be included in case a problem is identified, to help ensure the system cannot be turned on prior to repair.
- Warning signs should be applied to the in-feed and out-feed apertures to prevent an operator from reaching into the machine while the X-rays are on.
- A warning light tower should be included to indicate when the X-ray source is on. If the warning light becomes non-functional, the system should not allow the X-ray source to be turned on.
- Country-specific labeling in the local language should be applied to the machine when required.
- Every machine should be radiation tested after manufacturing, before shipment, and additional testing done at the customer site once installed.
- All radiation survey records are kept on file at the vendor’s location.
In addition to these manufacturing and design regulations, there are local regulations and best practices that should be followed as well, including filling out annual radiation surveys and registering x-ray equipment with authorities.
You can read more details about these safety requirements and protocols in this white paper: X-ray Inspection of Food Products: The Safety Facts You Need to Know.