In my 16 years, this one appears to have passed me by.

I am advised that when using Class M on site dust extraction (industrial vaccuum for want of a better description) it is considered to be an LEV system, therefore, is subject to 12 to 14 month thorough examinations.

This is stated in CIS69, however, the extraction we use is interchangable. It may be attached to a chop saw one minute, then a sander the next.

With different tool attachments being used, therefore, a lot of variables, how would one practically achieve a reliable thorough inspection on this particular arrangement?

I look forward to everyones comments,

Refgizmo

Thanks.

Often the attachments are provided by the user, who may be a sub contractor.

I don't see, presuming the thorough inspection has to be carried out by a professional provider, all the attachments would be made available at the time.

There seems to be far too many variables to give any substance to an inspection report.

When people test LEV often all they do is just measure the level of “suck” and if it is above some arbitrary number they say it has passed. This not what is required under COSHH. What they should be doing is establishing whether the LEV actually controls the risk airborne hazardous substance to the level that has been established as “safe” from the risk assessment.  As Chris has said, one of the most useful tools for getting a feel for that is a smoke tube perhaps combined with some form of back lighting.  Each tool will work differently and so you need to look at each tool that can be used with the LEV.

Very interesting thread. I would argue that such devices are not neccssarily a control to keep under the WEL, but are a general control, unlike "normal" LEV. I would point out that use of smoke devices does not MEASURE performance and is a qualitative and not quantitative, test, and therefore of limited use.

The smoke test is more suited to Fume and vapour extraction LEV Systems and not Dust Extraction LEV Systems.

Dust particles which behave differently and are ejected at velocity are not representive to smoke being caputured.

The test carried out in these situations to prove effective capture is a Tyndall Lamp test which shows the effect of the capture of a dust cloud and not a smoke test.