A refuse sack is judged on three things: its size, its gauge (thickness) and its CHSA rating (how much weight it can carry). This guide explains each one, so you can pick a sack that fits your bin and survives your waste without paying for strength you don't need.
The main types of refuse sack
The type you need depends on what goes in the bin and how the waste is collected.
• Black refuse sacks: the general-purpose choice. They are opaque, so they hide the contents.
• Clear refuse sacks: let you see what is inside, so they suit recycling and any waste that must be checked.
• Coloured refuse sacks: used to separate waste streams. Follow your own site's or contractor's colour code.
• Compactor sacks: larger sacks made for compactors and big bins.
• Bin liners: shaped to fit pedal, square or swing bins.
• Compostable and biodegradable sacks: for food waste or sites with a compostable collection. Check what your waste contractor accepts first.
How sack sizes work
A sack size is usually quoted as three numbers, in inches or millimetres. Take 18 x 29 x 38 inches, which is 457 x 737 x 965 mm:
1. Folded width (18 inches, 457 mm): the width of the sack with its side gussets tucked in.
2. Open width (29 inches, 737 mm): the width across the sack once the gussets are opened out. This is half the distance around the sack's mouth.
3. Length (38 inches, 965 mm): from the opening to the base.
Suppliers don't all list the numbers in the same order or wording, so check the product page to confirm which figure is which before you compare sacks.
Matching a sack to your bin
For a round bin:
1. Measure the distance around the rim. Divide it by 2 to get the open width you need. A 58 inch rim needs a 29 inch open width.
2. Measure the bin's height and add about 7 inches for overhang and tying. A 31 inch bin needs a 38 inch length.
For a square or rectangular bin, the open width is the long side plus half the short side. The length is worked out the same way, as the bin height plus about 7 inches.
A sack that is too small slips into the bin, and one that is too long wastes plastic and money. Many suppliers also quote litre capacity, but this varies between suppliers, so measure your own bin rather than relying on the figure.
Not sure which size to order? Use our Refuse Sack and Liner Finder, which filters by bin size, colour, type and strength.
What gauge means
Gauge measures the thickness of the polythene film a sack is made from. 100 gauge equals 1 mil, which is 0.001 inch or 25.4 microns, so each gauge is 0.254 microns.
|
Gauge |
Mil |
Microns |
|
70 |
0.7 |
17.8 |
|
100 |
1.0 |
25.4 |
|
150 |
1.5 |
38.1 |
|
200 |
2.0 |
50.8 |
|
250 |
2.5 |
63.5 |
A higher gauge means thicker film, which usually means a tougher and more expensive sack. But thickness is only part of the picture. Two sacks of the same gauge can perform differently, because strength also depends on the plastic used and how the film is made. That is why gauge is a useful guide to compare like with like, but not a guarantee of how much a sack can carry.
That guarantee is what the CHSA rating provides.
What the CHSA rating means
CHSA is the Cleaning & Hygiene Suppliers Association, the UK trade body for the cleaning supplies industry. Its Plastic Sacks accreditation scheme checks that sacks do what the label says, so what is on the box is what is in the box. Members' products are audited by an independent inspector against the scheme's specification and the CHSA Code of Practice.
The four duty grades
Each grade is defined by a weight rating, shown in kilograms on the pack:
|
Duty grade |
Weight rating |
|
Light duty |
5 kg or 8 kg |
|
Medium duty |
10 kg or 12 kg |
|
Heavy duty |
15 kg or 18 kg |
|
Extra heavy duty |
20 kg |
CHSA's published grades stop at 20 kg, so check the label carefully if a sack claims a higher rating.
How a sack is rated
A sack's duty is the weight it can hold without splitting. CHSA tests this with a drop test based on BS EN ISO 7965-2:
1. The sack is filled to the weight it is being rated for, for example 15 kg for a heavy duty sack.
2. It is dropped from a height of 1.5 metres.
3. It is inspected for splits.
4. This is repeated on a batch of ten sacks. At least nine of the ten must come through undamaged for the batch to pass.
5. Only sacks that pass can carry the CHSA dumbbell logo, which shows the weight rating.
The filler is a purpose-made weighted bag, a change the scheme made around 2014 so that results are consistent from one test to the next. Members run the tests themselves, and the independent inspector reviews their procedures and audits their products.
What the rating does and doesn't tell you
The CHSA rating is a real performance test, which makes it a more reliable guide than gauge alone. It does not cover every kind of waste. A sack that passes at 15 kg can still be punctured by sharp edges, so use a higher grade for broken glass, bulky offcuts or building waste. It is also a drop test result, not a safe carrying weight, so keep within your manual handling limits when lifting full sacks.
Choosing the right sack
Match the grade to what goes in the sack, not to the price. These are our general recommendations, and the sack must also fit your bin.
|
What you are throwing away |
Suggested grade |
|
Office paper, bathroom and light waste |
Light duty (5 kg or 8 kg) |
|
General office and retail waste |
Medium duty (10 kg or 12 kg) |
|
Kitchen, catering and mixed commercial waste |
Heavy duty (15 kg or 18 kg) |
|
Bottles, bulky or heavy trade waste, items with sharp edges |
Extra heavy duty (20 kg) |
When in doubt, go one grade up. A sack that splits costs more in clean-up time than the extra few pence it costs to step up.
Browse our black, clear and compactor sacks, buy in bulk with pallet deals, or use the Refuse Sack and Liner Finder to narrow the range by size, colour and strength.
