Plastic Bag Gauge Explanation

What does gauge mean when describing a polythene bag?

Gauge is the measurement of thickness of standard low density plastic bags. It is related to the SI measurement of microns as 1 micron = 4 gauge. Typical gauge sizes and microns equivalent are:

  • 100 gauge = 25 microns = 0.025mm = Very light-weight, economy black bin liner typically sold in discount stores.
  • 120 gauge = 30 microns = 0.03mm = Standard bin liner.
  • 160 gauge = 40 microns = 0.04mm = General purpose, quality black bin liner for domestic kitchen waste.
  • 200 gauge = 50 microns = 0.05mm = Heavy duty black bin liner - suitable for commercial kitchen waste.
  • 300 gauge = 75 microns = 0.075mm = Heavy duty garden waste bag.
  • 400 gauge = 100 microns = 0.1mm = Typical rubble sack when gauge is not specified.
  • 500 gauge = 125 microns = 0.125mm = Tough rubble sack - suitable for up to 40kg load.

Regardless of the thickness, sharp objects will puncture polythene (glass and metal). Thin bags will tear by pure weight or once punctured, however the thicker the bags will not tear easily without first being punctured.

Some bags are made from medium or high density polythene. This makes them more crinckly (like a supermarket carrier bags) and can be made thinner for the same strength. The thickness in microns is used to describe these bags:

  • 4 microns = the thinnest paper wate bin liner we have ever seen (hardly stronger than a tea bag!)
  • 6 microns = thin bin liner used in hotels