X-Ray Inspection Services & Technology for the Food Industry
    Frequently Asked Questions

    Q        What contaminants can x-ray systems detect in food products?
    A        Generally, anything that is denser than the product will be detectable.
              This includes most hazardous materials such as:
                     Metals
                     Glass, stone, etc.
                     Bone (in some cases. Contact OnGuard for further information)
                     Shell fragments in seafood

    Q        Is there anything it can’t detect?
    A        Unfortunately the x-ray system is not a universal foreign material detector!
              Some materials are not detectable because of low density, or because they are too thin
              to make a detectable signal in the x-ray image. The following are typically not  
              detectable:
                 Paper, cardboard and wood fragments
                 Plastic film, aluminum foil, rubber gloves
                 Hair, string, insects
                 Pits mixed in with fruit, shells in nuts, cartilage in meats

    Q        What about plastics and rubber?
    A        Some are detectable and some are not. It depends on the density.

    Q        How can I be sure the contaminant is detectable by x-ray?
    A        OnGuard will test the product free of charge. Send a sample of good product together
              with the contaminant (in a separate bag). A Product Test Report will be sent to you.

    Q        Is there a simple test?
    A        Drop the contaminant into a glass of water. If it floats, it will not be detectable in most   
              products. If the object sinks it may be detectable. Of course this is just a generalization,
              as detectability depends on the relative density of the contaminant compared to the
              product, as well as other characteristics such as thickness and homogeneity.

    Q        Does it matter if the product is frozen?
    A        No. Unlike a metal detector (which is measuring conductivity), x-ray only sees density
              differences. This means that x-ray is especially effective when inspecting
              conductive products like meat or cheese. Its sensitivity to Stainless Steel is vastly better
              in most cases

    Q        Can x-ray be used to check product integrity?
    A        In many cases it can be used to confirm the presence of an object or correct placement
              within a pack. Contact OnGuard for further details.

    Q        Are x-rays dangerous? Do we need to take special precautions or wear lead clothing?
    A        No. OnGuard’s systems comply with safety regulations that prevent unsafe exposure of
              operators and bystanders. Just like airport security x-ray machines, they are designed
              so that there is negligible x-ray leakage from the cabinet. Each time OnGuard installs the
              system, our Technician has to measure x-ray leakage to ensure that it is safe.

    Q        Do we need a licence?
    A        No. In Ontario, OnGuard’s safety procedures have been approved by the Ministry of Labour
              so the service can be used safely without the need for registration. In other provinces,
              OnGuard will take care of necessary registration procedures.

    Q        Are x-rays likely to harm our product?
    A        No. The x-ray system used low-power x-rays that cannot cause any changes to food
              or pharmaceutical products. Food Irradiation (to kill bacteria) uses gamma radiation over
              one million times the energy of our x-ray systems.
OnGuard Product Inspection Inc.
1235 Fairview Street, Suite 331, Burlington, Ontario  L7S 2K9
Phone: (905) 690-2868   Fax: (905) 690-7871
Email: syoung@onguardinspection.com