2 replies to this topic

[MEM]

We extrude and thermoform plastic packaging for the food industry.  I'm trying to understand the requirements for magnet validation in this application (SQF).  I have found the HACCP International Food Safety Standard 0909MAGSEP 2-2021, but that appears to be for actual food processing, not necessarily the packaging materials.  

 

Can anyone point me in the proper direction to identify the guidelines to specify min strength and validation requirements in plastics packaging?

[clrmwebb4350]

 We used to have magnets listed as preventative step but it was too much trying to validate the magnets so we removed it. The gate size in our molds is very restrictive and will not allow metal to pass through or if it does it will be encased in plastic, thus not a food safety risk for us. We produce food grade covers and nozzles. 

 

Maybe others will have more insight but that is my experience. We are SQF certified. 

[jfrey123]

It's been awhile since I dug into magnet calibrations, but if I'm remembering correctly you want to look at two aspects:  determining the strength and shape of a magnet given where it will be located (to ensure effectiveness), and then ensuring the magnet is performing at its prescribed strength through your verifications (because magnets can't be recalibrated, they lose their strength over time).

 

Plate magnets were not effective in my spice plant as the powders and granulated product flowing over it would eventually push off anything captured.  Bar magnets in a grid shape were effective as product dropped through them as it allowed product to pass and metal to remain captured on the bottom side of the bars.  The magnets were already in-use when we went to our first SQF certification, so we wrote up a validation using 50lb of test material and tested the magnet's ability to capture metal flake and larger items (nuts, bolts, etc).  After our own in-house validation, we used those existing magnet strengths in our written program to set which strength should be purchased in the future and define the verification pull strength tests we performed to determine whether the magnet was still effective.

 

Starting with a written standard such as that food one you found can be a good starting point.  At the end of the day, depending on where your magnets are and how you intend them to control metal hazards is something you'll likely need to write up and present yourself based on your facility's needs.  If the magnet was designed into the machines you're using to produce the packaging materials, perhaps too you can ask the manufacturer for any data they have supporting the inclusion of that magnet into their design.