Worktop materials compared for specifiers

At a glance

Natural stone entries are NSI’s general statements, not data for a slab. Silica: HSE, SafeWork NSW. ‘Ask’: no figure in the sources read.

Compare declared properties, not adjectives

No worktop wins on every count, so the useful comparison is the one you can write into a specification: which properties a supplier will declare, by which test method, in which edition. Retail adjectives such as ‘hardwearing’, ‘heatproof’ and ‘low maintenance’ cannot be checked. A water-absorption percentage to a named method can.

The drawing groups the seven families this sheet compares. It is a schematic, not a photograph: the real colour, veining and texture of a slab decide how it looks, so approve a sample of the actual slab (see sample hierarchy and approval).

The test behind each property

The table names the test behind each property, family by family. It is a map of what to ask for. It gives no pass mark, because none was found in a source we could read, and because a standard that sets a test method does not set a limit for every worktop. Statuses are those on the BSI Knowledge listing on 6 November 2026: every edition named was current, and several were also marked under review. The texts themselves were not read.

Three gaps are worth knowing. No test method for thermal shock or for stain and chemical resistance of natural stone turned up in the sources read, so for natural stone those behaviours rest on trade-body guidance and on what the stone workshop is prepared to test. BS EN 15388 is the only standard we found that is written for worktops, and its listing covers agglomerated stone, not natural or sintered stone. And BSI’s plain-language summaries describe agglomerated stone as bound with cement, while the BS EN 14618 listing says such products are made mainly of cement, resin or both: ask the supplier to confirm which standard its resin-bound quartz is declared to.

Manufacturers declare values, and a declaration is a statement by the maker, not an independent result. One sintered stone maker’s published guide (August 2024) shows what a declared set looks like: water absorption below 0.1%, a minimum bending strength of 50 N/mm² at 12 mm and 60 N/mm² at 20 mm, stain resistance and chemical classes, and thermal shock ‘resistant’, each against a named ISO 10545 part, and grouped as a dry-pressed ceramic tile of very low absorption under BS EN 14411. It is one product and is not a benchmark for any other: ask for the sheet for the product you are specifying.

Silica: the column that changed in 2026

Silica is now part of the comparison, because HSE published its first COSHH guidance on engineered stone on 11 May 2026. HSE’s page, updated 29 April 2026, defines engineered stone as artificial stone made from crushed natural stone or minerals bonded together with resin, and its press release says engineered stone, widely used in kitchen and bathroom worktops, can contain up to 95% crystalline silica. The controls HSE lists for employers include working stone with the lowest crystalline silica content, on-tool water suppression, powered respirators with an assigned protection factor of at least 20, and health surveillance. HSE says the guidance effectively rules out dry cutting unless an equally effective control is shown, and that it is not a new law or a formal prohibition.

Two limits on what that means for a specifier. The guidance is written for employers who work the stone: it does not mention designers or specifiers, and it concerns dust made when stone is cut, ground or polished, not a finished surface. And natural stone is not dust-free: HSE’s guidance for installers says respirable crystalline silica is in most rocks, sands and clays and in products such as bricks, tiles and concrete, and that dust from natural, artificial and engineered stone can cause serious illness.

For a sense of scale, SafeWork NSW, an Australian regulator that has banned engineered stone containing at least 1% crystalline silica, publishes typical levels for materials: granite 20 to 45% (typically 30%), marble and limestone about 2%, and ‘manufactured stone’ 93% or higher. Those are typical levels for materials, not a guarantee for any product, and we found no figure for natural quartzite, sintered stone, solid surface or terrazzo. NSW’s definition of engineered stone leaves out resin-free sintered stone and porcelain; that is where a law draws a line, and it is not a statement that those slabs contain no silica.

What to ask for: the crystalline silica content by weight; the safety data sheet; how the partner cuts, edges and cleans the stone (wet methods or on-tool extraction); and whether sink, hob and tap cut-outs are made in the workshop. HSE’s installer guidance asks for cut-outs to be made off site where possible. This sheet does not say any surface is safe or unsafe: the supplier’s data and an occupational hygienist decide that. Our engineered stone and silica guidance sets out the HSE position in full.

Stain, etch, heat and scratch: what the sources support

• Etching belongs to the calcite stones. The Natural Stone Institute (NSI) says the calcite crystal in true marble is vulnerable to mild acids, including those in kitchen and bar settings, and that the person choosing marble for such places should accept the maintenance and the patina. It says limestone and travertine, also calcium-carbonate stones, are likewise vulnerable to mild acids, and that serpentine, often mistaken for marble, is magnesium-silicate and more acid resistant. A sealer does not change this: see sealing, staining and etching of stone.
• Quartzite is not immune. NSI says siliceous stone is generally resistant to most acids found in kitchens but that acidic cleaners are still not recommended, because such stones may contain trace minerals that are acid sensitive, and that the hydrofluoric acid in some rust removers attacks all stones, granite and quartzite included. The trade also sells some softer stones, including dolomitic and part-marble ones, as quartzite, which is why a sample of the actual slab matters. Our quartzite guide makes the same point.
• Heat needs care on every stone. NSI recommends trivets or mats, while noting that many stones can withstand heat. For granite it gives about 250 °C as typical heat resistance, and warns that localised heat can crack it. The sources read give no comparable figure for the other surfaces, so ask the maker for its hob and hot-pan guidance, and for the thermal shock result where a test exists.
• Scratching. NSI says the minerals in most granites are harder than kitchen utensils. Solid surface is described by its standard as having renewable surfaces, which is the point of choosing it where light scratches are expected and can be sanded out. We found no source that ranks the surfaces for scratch resistance on a common scale.
• Staining. NSI gives granite absorption of 0.05 to 0.40% by weight and limestone from under 1% to over 10%. It states a position on sealing countertops (adopted 2006): most granite countertops do not need sealing, though many benefit, and it says that in many cases it makes sense to seal marble and granite countertops with a quality sealer.

Thickness, weight, joins and repair

Weight matters for the cabinet below, for handling and for fixings. Without a declared density the honest answer is arithmetic: weight in kg/m² is the thickness in millimetres multiplied by the density in g/cm³. The table uses three illustrative densities, not data for any product; use the declared apparent density on the supplier’s sheet.

A worked example: a 1.2 m by 3.0 m top is 3.6 m². At 30 mm and an illustrative 2.7 g/cm³ it weighs about 290 kg before the base is counted. Our stone page describes tops as typically 20 mm or 30 mm thick, and our stone journal puts a large marble table top at 200 to 250 kg, so the order of magnitude is right.

Joins and repair. Stone slabs meet at joints that show, so book-matching and joint position are design decisions to settle on the drawing. Solid surface is the one family whose standard describes inconspicuous seams, and our solid surface page says seams are bonded and sanded. Terrazzo can be reground and repolished in place, as our terrazzo page says. For sintered stone and engineered quartz we found no source on seams or repairs, so ask the partner how each is made and mended. For overhang, span and edge thickness, which depend on the material and its support, see table-top thickness, overhang and span.

Questions that decide it

• Will acids reach the surface every day? A bar, a coffee station or a hotel kitchen points to siliceous stone or a manufactured surface, or to a client who accepts a patina on calcite stone.
• Do hot pans or hob surrounds matter? Trivets everywhere; ask for the maker’s written advice and any thermal shock result.
• Do you need long runs and few joints? Ask the partner about slab sizes and where joints fall; solid surface is the family described as having inconspicuous seams.
• Who will repair it, and how? A stone specialist can often refinish stone; solid surface is renewable; ask how engineered quartz and sintered stone are repaired.
• What does the safety data sheet say? Ask before the order, not at fabrication.
• Has the production slab been approved? See stone sample, slab and book-match approval.

Worktop: [material, variety or colour reference], [30] mm thick, to approved sample [ref] cut from the production slab. The supplier shall declare, with test method and edition, apparent density and water absorption [BS EN 13755 / BS EN 14617-1 / BS EN ISO 10545-3], flexural strength [BS EN 12372 / BS EN 14617-2 / BS EN ISO 10545-4] and, for manufactured surfaces, thermal shock and chemical and stain resistance [BS EN 14617-6 and -10 / BS EN ISO 10545-9 and -14 / BS EN ISO 19712-2]. Values to be issued with the safety data sheet before fabrication.

The supplier shall state the crystalline silica content (per cent by weight) and issue the safety data sheet before order. Fabrication by wet methods or on-tool extraction as current HSE guidance requires, with sink, hob and tap cut-outs made in the workshop, not on site. Controls to be confirmed in writing. [Contract adviser or occupational hygienist to confirm.]

The supplier shall issue written care instructions before handover: cleaner type and pH, any sealer and its reapplication, and the maker’s guidance on hot pans and hob surrounds. Trivets or heat mats to be [provided / advised] at handover.

Standards and sources

• HSE: working engineered stone (updated 29 Apr 2026); press release 11 May 2026; installing stone worktops: read 6 Nov 2026.
• SafeWork NSW, what are crystalline silica and engineered stone; Natural Stone Institute consumer pages; Stone Federation GB, Natural stone in your home: undated; read 6 Nov 2026.
• Test standards named in the tables (BS EN 13755, 12372, 13161, 14157, 12670; BS EN 14617 series, 14618, 15388; BS EN 14411, BS EN ISO 10545 series; BS EN ISO 19712-1 and -2): editions as shown in the tables, all Current on BSI Knowledge, 6 Nov 2026. Named, not read.

Questions we are asked

What is the difference between quartzite and quartz worktops?

Quartzite is a natural stone, a metamorphic rock made mostly of quartz. ‘Quartz’ as a worktop usually means engineered stone: crushed natural stone or minerals bonded with resin, which HSE says can contain up to 95% crystalline silica. The names are one letter apart, so check which is being specified.

Which worktop material contains the most silica?

In the sources read, engineered stone: HSE says up to 95%, and SafeWork NSW lists ‘manufactured stone’ at 93% or higher, against typical levels of 20 to 45% for granite and about 2% for marble and limestone. HSE’s guidance concerns dust made when stone is cut, ground or polished, not a finished surface. We found no figure for quartzite, sintered stone, solid surface or terrazzo, so ask for the safety data sheet.

Is sintered stone silica-free?

We could not confirm that. SafeWork NSW leaves resin-free sintered stone out of its definition of engineered stone, but that is a legal definition, and HSE says respirable crystalline silica is found in tiles as well as stone. Ask the supplier for the safety data sheet and the controls used when the slab is cut.

Which worktop is the most heat resistant?

The sources read give one stone figure: granite is typically heat resistant to about 250 °C, but NSI discourages localised heat because it can crack the stone, and it advises trivets on all stone. For the other surfaces ask the maker for written hob and hot-pan guidance and for the thermal shock result.

Does marble or limestone stain, or etch, or both?

Both can happen. Staining is a liquid carried into the pores; etching is acid reacting with the calcite and dulling the surface. A sealer slows staining but does not stop etching. See our sheet on sealing, staining and etching.

Can I specify a worktop by one property, such as hardness?

It is risky. No single property covers heat, stain, scratch, silica and repair together. Ask for the declared set: absorption, strength, thermal shock and chemical and stain resistance, each with its test method and edition.