By the hardness and finish of the surface, not by how dirty it is - and always start with the least aggressive pad that might work.

The rule is that the pad must be softer than the surface. Anything harder removes material rather than soil.

Non-scratch pads suit coated cookware, plastics, painted surfaces, glass and polished finishes.

General-purpose grades handle stainless steel, ceramics, tiling and most kitchen equipment.

Heavy-duty grades belong on cast iron, unglazed floors, grills and industrial equipment where the surface can take it.

Escalate only if the milder pad genuinely fails after proper dwell time with an appropriate chemical. Soil that resists the correct pad usually needs different chemistry, not more abrasion.

Within a manufacturer's range, generally yes; across the industry, no - so the grade description matters more than the colour.

Most manufacturers use a consistent scheme within their own products, and staff learn it quickly.

There is no universal standard, so a colour from one supplier may correspond to a different aggressiveness from another's.

Mixing suppliers on one site therefore causes surface damage: staff apply the colour convention they learned and get a different pad.

Standardise on one supplier's range where possible, and where that is not practical, label the storage by grade rather than relying on colour.

Note that colour is also used for area coding in some schemes, which can conflict directly with grade coding - decide which convention the site uses and document it.

Permanent scratching and dulling - and a roughened surface that holds soil and is harder to clean afterwards.

On stainless steel, an aggressive pad leaves a scratch pattern that never polishes out with normal cleaning. On brushed finishes, scouring across the grain is immediately visible.

On coated cookware and appliance finishes, the coating is removed and the item is effectively ruined.

The less obvious consequence matters more in a commercial setting: a roughened surface has more area and more crevices, so it collects soil faster and is harder to clean and to sanitize. In food environments, a scratched work surface is a hygiene issue as well as a cosmetic one.

Test in an inconspicuous place first and work with the grain on brushed metal.

Once the damage is done, the only remedies are refinishing or replacement.

Yes - the open web holds food residue and organisms, and pads should be colour coded, cleaned and replaced like any other cleaning textile.

The structure that stops a pad clogging also gives residue somewhere to sit, and pads used on raw food, waste bins or washrooms carry that to the next surface.

Rinse thoroughly after use, wring or shake out and store where they can dry.

Colour coding by area is standard practice in food and healthcare settings, and needs to be reconciled with any grade-based colour convention.

Replace on a schedule. A pad that is glazed, flattened or discoloured is both less effective and more contaminated.

Never use the same pad across raw and ready-to-eat food areas, or between washroom and kitchen - this is a common audit finding and an obvious transmission route.

When it feels smooth, has flattened, or has clogged with residue that will not rinse out.

Abrasive particles wear away and the web compresses with use. A worn pad requires more pressure for less effect, and pressing harder on a worn pad is how surfaces get damaged.

Clogging with grease or burnt residue stops the abrasive contacting the surface at all.

Discolouration and odour indicate contamination rather than wear, and both mean replacement.

Pads are inexpensive relative to the surfaces they are used on and to the labour of using a worn one, so replacing generously is the economic choice.

In audited environments, a defined replacement frequency is easier to evidence than a judgement about condition.

Only non-scratch grades, and even then a cloth or sponge is usually the better choice.

Non-stick coatings are soft relative to most abrasives. Any general-purpose or heavy-duty pad removes them.

Non-scratch pads are formulated for exactly this and are safe on most coated cookware, though repeated use still wears a coating over time.

Manufacturers of coated cookware and appliances often specify what may be used, and using something else can void a warranty.

For burnt-on residue on a coated surface, soaking with an appropriate cleaner is almost always more effective and less damaging than abrasion.

The same applies to painted, anodised, lacquered and printed surfaces - the coating is what carries the appearance and it is thin.

Pads for flat surfaces and even pressure, brushes for texture, corners and anywhere the surface is not flat.

A pad distributes pressure across an area and gives a uniform result on a flat surface, which is why floor machines use them.

Brushes reach into texture, grout lines, corners and around fittings that a pad skims over.

Brushes are also easier to clean and dry, which makes them preferable where hygiene matters and where the tool must be sanitized between uses.

Pads hold more soil and are usually more effective on burnt-on residue over a broad area.

Most operations need both, and the choice per task is usually obvious once the surface geometry is considered rather than the soil.