Wall chasing and silica dust
Updated: October 2026
You are about to cut a chase in brick or block, and the plan is a dust port, a Henry from the cupboard, or a title that calls the job clean. Wall chasing silica dust is why that plan is incomplete. The Health and Safety Executive treats this work as high risk. The person on the tool is most exposed, and anyone else in the cloud is affected. Products Compared did not measure a room. This page uses HSE's published control and the amazon.co.uk captures in our [wall chaser comparison](/hub/fireplaces-and-stoves/wall-chaser), dated 15 October 2026. Amazon links are affiliate links (tag pcuk26-21).
You are about to cut a chase in brick or block, and the plan is a dust port, a Henry from the cupboard, or a title that calls the job clean. Wall chasing silica dust is why that plan is incomplete.
You are about to cut a chase in brick or block, and the plan is a dust port, a Henry from the cupboard, or a title that calls the job clean. Wall chasing silica dust is why that plan is incomplete. The Health and Safety Executive treats this work as high risk. The person on the tool is most exposed, and anyone else in the cloud is affected. Products Compared did not measure a room. This page uses HSE's published control and the amazon.co.uk captures in our wall chaser comparison, dated 15 October 2026. Amazon links are affiliate links (tag pcuk26-21).
Our top picks
| Badge | Product | Dust on the listing | Extractor in the box | Supply | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Metabo Metabo MFE 40 wall chaser | Port, no hose | Tool only | 220–240 V corded | 8.6 | about £347.99 | View offer |
| Best value |  Einhell Einhell TC-MA 1300 wall chaser | Port, no vacuum | Not included | 230 V corded | 8.3 | about £89.99 | View offer |
| Alternative |  MAXXT MAXXT R2409-EU wall chaser | 40/35 mm port | Not included | 220–240 V corded | 7.4 | about £128.99 | View offer |
On this page
What the dust is
Chasing cuts masonry, and the fine fraction is respirable crystalline silica. HSE's workplace exposure limit is 0.1 mg/m³ as an 8-hour time-weighted average. On the chasing page, HSE says uncontrolled chasing can peak around 5 mg/m³. HSE's construction-dust guidance also says over 500 construction workers are believed to die from silica dust exposure every year. That sentence is HSE's, not a sales figure for chasers. Concrete and mortar are the materials on the chasing page. The MAXXT R2409-EU names foam blocks and hollow bricks, and it still ships without an extractor.
The control HSE publishes
Route the cable another way if you can. Where you cut, HSE's control is on-tool extraction to an M or H class unit, plus respiratory protection at APF 20. The examples are an FFP3 mask or a half mask with a P3 filter. A tight-fitting mask needs a face-fit test. Extraction does not capture all of the silica, so the mask stays on with the hose fitted. The class rating sits on the vacuum, not on the chaser's port. The cutting order is on how to use a wall chaser.
A Henry is not that unit
UK reviewers name a Henry, and some name a Kärcher, when the visible mess drops. HSE does not describe a Henry as an M or H class extractor. On the Einhell the port blocks when plaster flakes meet it. On the MAXXT R2409-EU, a Henry still let a little dust escape. On the R2409-UK-VC, one review reported clean chases with a taped Henry hose. Clean to the eye is not a class certificate. Do not dry-sweep the floor. Vacuum with a suitable class of machine, or damp the waste so it does not go airborne again.
Titles that outrun the box
Read the included parts, not the adjective in the title. The JAOGAUS bullets claim a water feed leaves no dust, and there is no review text. These sources do not show water as the HSE method. The SUSEMSE review describes a wet machine that tripped an RCD until it dried. The MAXXT R2409-UK-VC title says "with Dust Extractor" and the bullets say the vacuum is sold separately. The R2409-EU sizes the port at 40 mm outside and 35 mm inside, and the extractor is not included. The Metabo's included line is the tool. Matching a chaser to those facts is the buying guide.
Common questions
Why is chasing a silica job even in lightweight block?
HSE's chasing page covers concrete and mortar, which produce very high levels of respirable crystalline silica. The limit is 0.1 mg/m³ over 8 hours, and uncontrolled chasing can peak around 5 mg/m³. A foam block may throw a different cloud, and that difference is not a measured reason to drop the mask. The MAXXT listing that names foam blocks still includes no extractor. The control remains an M or H class unit plus RPE at APF 20.
What does HSE say to put on the tool?
On-tool extraction to an M or H class unit, with tight hoses and enough airflow, plus RPE at APF 20. The examples are FFP3 or a P3 half mask. Extraction does not capture all the silica, so the mask stays on with the hose fitted. For spells longer than about an hour, HSE points to powered RPE at the same factor. Route the cable another way if you can.
Is a Henry or a household vacuum enough?
No. Reviewers use a Henry or a Kärcher and report less visible mess. They also report dust that escapes, a blocked Einhell port, and Draper extraction one person called terrible. HSE does not describe a Henry as an M or H class unit. A domestic vacuum can improve the housekeeping. It does not replace the mask or the class of extractor.
Does the dust port mean the chase is clean?
No. A port is a hose connection. It is not a filter and it carries no M or H rating. The Einhell port blocks when plaster flakes arrive. The MAXXT EU port is 40 mm outside and 35 mm inside, and the extractor is still not in the box. Only the vacuum you connect could carry the class, and only if it is that class of machine.
What mask is required, and who needs a fit test?
Use RPE at APF 20, such as FFP3 or a half mask with a P3 filter. A tight-fitting mask needs a face-fit test, and you need to be clean-shaven on the seal. Other people in the room need protection too. A nuisance dust mask is not HSE's example. For a long spell without a break, consider powered RPE at the same factor.
Does a water-fed chaser replace the extractor?
Not on the evidence here. HSE's control is M or H class extraction plus RPE. The JAOGAUS bullets claim a water feed leaves no dust, and there is no review text. The SUSEMSE review describes a wet machine that tripped an RCD until it dried. Keep water off the electrics. A water feed is not a shown substitute for the extractor and the mask.
What should I do with the dust afterwards?
Do not dry-sweep it. HSE treats dry sweeping as its own dusty task. Use a suitable class of vacuum, or a wet clean-up that will not release the dust again when the floor dries. Bag the waste. The mask still matters while you clear the room, not only while the discs are turning.
Related pages
Sources
Public UK sources from the research digest, retrieved 15 October 2026.
- HSE: Chasing concrete and raking mortar (retrieved 15 October 2026)
- HSE: Construction dust (retrieved 15 October 2026)
- HSE: Silicosis (retrieved 15 October 2026)
- HSE: Construction information sheet CN2 (retrieved 15 October 2026)
- GOV.UK: Approved Document A, structure (retrieved 15 October 2026)
- Eden District Council: Wall chases (retrieved 15 October 2026)
- SELECT: Installation of cables (retrieved 15 October 2026)
- GOV.UK: Building work, replacements and repairs (retrieved 15 October 2026)
- GOV.UK: Approved Document P, electrical safety (retrieved 15 October 2026)