HACCP and Critical Control Points for Metal

HACCP is a food safety system. The letters stand for Hazard Analysis and Critical Control Points. The idea is simple. Find the places where a hazard can enter the food. Put a control at each place. Check the control, and write down the result.

Metal is one of the most common physical hazards in food. This guide shows how to handle it under HACCP with magnetic separation.

Step 1: find where metal can enter

Walk the whole line, starting at intake and ending at packing. At each stage, ask where iron or steel could come from. Common sources are:

• Raw materials. Grain, sugar, flour, spices and powders arrive with nails, wire, staples and rust flakes from harvesting, storage and transport.
• Sieves and screens. Wire mesh breaks and sheds fine pieces.
• Mills, mixers and pumps. Blades, bearings and seals wear and shed particles.
• Conveyors and elevators. Bolts, chain links and belt fasteners work loose.
• Maintenance. Swarf, filings and dropped fixings after a repair.
• Packaging. Staples and wire from sacks and cases.

Write each source down with the stage where it appears.

Step 2: decide which points are critical

A critical control point is a stage where a control can prevent the hazard, or reduce it to a safe level, and where no later stage will catch it. For metal, the usual critical points are:

1. Intake, to protect your own equipment from tramp iron in the raw material.
2. After each mill, sieve or mixer, to catch wear particles that stage creates.
3. Before packing, as the final check on the finished product.

The final point is the most important. Anything that passes it reaches the customer.

Step 3: fit a control at each point

A magnetic separator is the usual control for iron and steel. Choose the type to suit the product flow:

• Grids and grates for powders and granules falling through a hopper or sieve outlet.
• Housed drawer separators for enclosed transfer lines and pneumatic conveying.
• Liquid traps for syrups, oils, sauces and slurries in a pipeline.
• Plate and chute magnets for deep product beds on belts and in ducts.

At the final point, use the highest practical strength. SMAG rods are made up to 13,500 gauss, and at this strength they hold fine particles and work hardened stainless steel as well as ordinary iron.

For metals a magnet cannot hold, such as aluminium and copper, add a metal detector or a sieve at the same point.

Step 4: set a limit and a check

Each critical control point needs a limit and a way to check it. For a magnetic separator, the checks are:

• Strength. Measure the surface field with a gauss meter and compare it with the tested certificate supplied with the unit. Do this at least once a year, and after any impact or overheating.
• Cleaning. Clean the rods on a fixed schedule. A rod covered in collected iron holds new particles weakly. Record what is found each time.
• Condition. Look for cracked or worn tubes, damaged seals and loose fixings.

Write the schedule into the HACCP plan, and keep the records with it.

Step 5: keep records and review

Auditors want to see three things. That you know where metal can enter. That you have a control at each point. And that you check the control and act on the result.

Keep the certificate of magnetic strength for each separator, the cleaning log and the gauss meter readings together. Review the plan when a line changes, when a new material is introduced, and after any metal complaint.

The SMAG range

Santosh Magnetic Works makes grids, drawer housings, liquid traps, plate and chute magnets for food lines, in 304 stainless steel and with a tested certificate of magnetic strength for each unit. See the housed easy clean grid separator and the full separation range, or contact us with a line drawing and we will mark up the control points.