M&SM&S Washing Up Liquid

How we test fat removing power

The most important part of our tests is finding out how well each washing-up liquid removes fat from dirty dishes. To score washing-up liquids for fat removal, we pour 1.2kg of animal fat onto 742 plates. We then count the number of plates that each liquid cleans until the fat begins to be re-deposited. The more stars, the better.

How we test tough grease removal

How well the washing-up liquid removes baked-on grease. Our tough grease test simulates cleaning leftover fat from grilled meat or roast potatoes on metal cookware to reveal how products face up to this tough challenge. The more stars, the better.

How we test foam duration

How long the foam lasts before it looks like you need to change the water when cleaning everyday grime from plates. The more stars, the longer the foam lasted in comparison to other products. This star rating is indicative only and foam duration does not contribute to the total test score of each washing-up liquid.

How we test sustainability

Whether these washing up liquids contain chemicals that have any negative environmental effects. This includes whether they are biodegradable, harmful to aquatic life or persistent, which means the chemicals could linger and accumulate in waterways. In addition, we examine the packaging material to see whether it's recyclable or made from recycled materials and we also consider whether refills are available.