Dust Classifications

[Joe]

Can anyone enlighten me as to the difference between dust class L and M? I realise the L stands for low and the M for medium, but what sort of dusts fall within those categories? I'm thinking of getting a new extractor and don't know which class to go for.

Thanks

Joel

 

[FatFreddysCat]

They're German categories aren't they? I had to go and dig around and according to my Festool catalogue:

Dust category L
Filter performance: > 99 %
Materials: Hazardous dust with MAK values >1 mg/m3 and for NON-hazardous dust

Dust category M
Filter performance: > 99.9 %
Materials: Hazardous dust with MAK values > 0.1 mg/m3

MAK = Maximum exposure limit / Source: EN 60335-2-69 and IEC 60335-2-69 Annex AA

Which I suppose means that wood dust requires a Cat M shop vacuum as it is classed as hazardous. Guess who's recently had the HSE visit? :roll:

The inspector seemed to have a bee in her bonnet about the type of dust masks we routinely use, they're the disposable paper or cloth type and are apparently innefective against MDF dust. Can't see the boss springing for a set of air helmets just yet, tho

 

[CHJ]

.....
The inspector seemed to have a bee in her bonnet about the type of dust masks we routinely use, they're the disposable paper or cloth type and are apparently innefective against MDF dust. Can't see the boss springing for a set of air helmets just yet, tho

Doubt he will spring for a new set of lungs either but it could be what's needed if you are working without adequate protection.

 

[lurker]

The inspector seemed to have a bee in her bonnet

I think she may have had a bee in her bonnet as she rightly considers your boss is slowly killing you.

Assuming you are daily using MDF and are being exposed with inadequate protection - I'll give you 5 -10 years before you have to permanently be connected up to an oxygen cylinder.

Does that put her concern for you, into perspective?

 

[FatFreddysCat]

Assuming you are daily using MDF and are being exposed with inadequate protection - I'll give you 5 -10 years before you have to permanently be connected up to an oxygen cylinder.

I've been in this environment using MDF for quite a bit longer than that, but then I routinely attach power tools to my own Shop Vac (the firm is too mean to buy one) in addition to the mask. The inspector didn't enquire about that at all, nor about ear defenders, nor gloves when handling finishing chemicals, which I think shows a somewhat inconsistent approach. The filters on it don't come with the German dust category coding, only a BS-EN code which corresponds to Cat L. I am actually the only person in the shop who bothers to use a vac and the lack of concern by our management does bother me.

My biggest concern is actually deafness. Even though I have almost always used ear defenders (these days made to measure) I'm still showing early signs of deafness.