Dust Class M v OSHA

I’m looking at the Makita cordless dust extractors and I’m confused by the ratings.

• In the US the XCV04 & 07 range are listed as OSHA compliant for slica dust  which is 99.97% of particulates .3 microns and larger
• In the UK the  DVC861, 863, 864 seem to be the same machine but are only listed as Class L – Removes 99.0% of dust with limit value
• The UK requires Class M for silica dust  which is 99.9% of dust.  That seems to be similar to the US OSHA

Can anyone explain why the cordless vacs are not Class M?

They’re not powerful enough.

Because there is a difference between filtration class and vacuum class. 

The filters might be good enough to be an ‘ M class ‘ filtration ( because they are HEPA filters I believe )

But for a vacuum to be rated as m class u need more then just a good filter. Most important extra is that your vacuum continually checks the flow rate of the air. If it drops under a certain level ( indicating something is clogged up and your vacuum isn’t working as it should ) then the vacuum needs to give you a visual or audible alarm.

There’s a few other little things your vac needs to do/ have to be considered an M class but the reason above is the more important

Thanks for the information, I suspected that might the case. So while OSHA has the same filtration it doesn’t have the design features or safeguards of Class M.

I’ll stick with lugging the corded and extension around. My next project is a narrow 4 storey refurb, one room on each floor so I was hoping to simplify the clambering up and down the stairs!

I think I’d consider another brand for cordless as the convenience would outweigh the hassle of a different charger.

There’s only 1 cordless m class and that’s a hilti that costs… Obnoxiously much 😀

Yes, I’d seen the Hilti which is why I got excited seeing the Makita US site extol their capabilities for s dealing with silica, which sounded like M in this country.

On a related note, Makita do have some great on-tool dust accessories featured prominently on their US site. I’ll have to investigate those too. Has anyone got hands on experience of them?

I was thinking of starting with the DX02 for my SDS 243

The DX units for the rotary dhr243 works excellent. It’s bulky but not heavy. I’d say it captures 90+ procent of dust

The biggest issue for me in doing old house refurbs is that the dust spontaneously accumulates as soon as you remove the old carpets and start lifting boards, replacing windows, insulating roof spaces, knocking out plaster for new back boxes, routing  new cables and plumbing. 

It’s a constant battle and if you’re spending a day doing back boxes it’s easy  to carry the cordless tools from one box to the next  but the vac is a palava that is often ignored – stick on a face mask and live with the dust.

So while the Makita cordless isn’t Class M, it is more likely to be used…. or maybe I should value my health to be worth  more than £1000 for the Hilti.

Well the Makita is still a HEPA filter. It’ll filter just the same dust as the hilti if not more.

The Makita just doesn’t give you an alarm if the filter for example is clogged up to the point that dust extraction doesn’t work anymore and alot more dust will be escaping instead of being sucked up

The other feature of Class M vacs is an auto clean filter, and dust bags rather  than an open bin. I’m not sure if that is mandatory but it is certainly essential.

I’ll have to dig into  the Makita details later.

Auto clean filter is not mandatory for an M class. It’s a feature many times on thee more expensive m class vacs but it’s not mandatory.

Dust bags can also be gotten for every vacuum, L or M class

Hi 

My  Makita m class hoover  is beeping  I have clean the filter very well but still beeping 

any one have an issue with that 

Thanks