Would need to see the CoSHH assessment to see the justification for the contractors argument.

Originally Posted by: FlashingBlade

Originally Posted by: Ian Bell2

Would need to see the CoSHH assessment to see the justification for the contractors argument.

There isnt one as the material being processed isnt inherently hazardous. It generates dust during processing which could then be hazardous upon inhalation as cotton/wool dust (2.5 and 10 mg/m3 respectively as per EH40. 

If its a respiratable dust then it is a substance hazardouse to health and is covered by COSHH - dont be fooled that its OK as no safety data sheet!

I would still expect to see some form of screening assessment, to justify the decision of the dust being non hazardous - and no requirement for a full CoSHH assessment.

However as indicated by others I would guess it will get captured under the general dust clause of CoSHH

Given Cotton Dust has a lower EH 40 value 2.5 mg/m3 than its constituent Cellulose 4mg/m3 there is a need for control to prevent disease such as Byssinosis (mill workers lung).

As with all combustibles you would want the extraction system under frequent maintenance & cleaning.

Such considerations of course are dependent upon the systems design being adequate for extraction with reagrds to purposes of health rather than ambient air quality.

By exmaple a fume cupboard has a "working" height marked for its sash opening - fully open and the extraction is insufficient to draw contaminants, closed to mark and the inward air flow prevents the contaminants seeping back in to the room. Same extraction in both scenarios.

I'm clearly going against the flow here.  My argument is that if an extraction system has been installed for reasons that have nothing to do with COSHH, and it isn't a control measure referred to in the (COSHH) risk assessment (on the basis that it hasn't and wouldn't be provided for the protection of health), then it doesn't need to be maintained as a COSHH control measure (as it isn't a COSHH control measure) and therefore doesn't need the thorough examination and so on (which you wouldn't be able to do anyway as if it hasn't been designed to protect health, you won't have any relevant design criteria to compare it against - as the OP alludes to).

It's like asking for a face fit test for a face covering worn under Covid guidance (seeing it as RPE which it is not).  Or an EN169 certification for a pair of sunglasses (seeing them as protective eyewear which they are not).  It might look like something that is a health control measure, but it is outside the scope of H&S regulations.

The answer is simple providing you know what the ventilation has been provided for. Is it to provide general / dilution ventilation for the area which then isnt LEV.

Or was it to capture the release of dust at source to prevent exposure then it would be LEV.

People confuse general ventilation with LEV systems all the time, the difference is general ventilaion may or may not draw the air flow (contaminated or not) accross the breathing area/zone off the operator, whereas Local Exhause Ventilation captures the contaminated air at source of release or at a close proximity to the release without drawing the contaminant across the operators breathing zone/area (If designed correctly).

If the system is being used for general process ventilation then it will not require inspection. If it is there to control the levels for exposure then it is LEV. 

You mentioned that it was to help the process as opposed to being for control of exposure then thats fine, but both types of system should'nt be confused and dont normally get uses to provide both purposes.

If you have concerns of exposure level from dust should the ventilaion system fail then the process should be interlocked to the ventilaition system. This will prevent the process for running and contanimating the air without the ventilation running. If you are concerned that there could be a sudden buildup of contaminent then and interlocked LEV system could be considered.   

Let's look at this from a legalistic perspective.

The case law says that "practicable" requires what is possible in the light of "current knowledge and invention", which is a regularly moving parameter as technology moves on.

Assessing what is "reaonably practicable" means working out the cost in terms of time, money and effort and deciding whether the cost of mitigating a risk is "disproportionate" or "grossly disproportionate" depending on which legal judgment you prefer, but with the onus on the duty holder in both criminal and civil proceedings to prove (on the balance of probabilities) that they have done all that is "reasonably practicable".

So, imagine this process without extraction and say the exposure of workers might be 50% of the occupational exposure standard.

It might cost £X,000 to reduce that exposure to 10% of the occupatational exposure standard and that might NOT be reasonably practicable.

However, if the same £X,000 is spent to assist with quality and not to reduce exposure, but where a side effect is to reduce exposure to 10% of the OES then the marginal cost of reducing exposure is NIL.

ERGO it is reasonably practicable to reduce exposure to 10% by the installation of extraction.

Then for operational reasons it will make sense to check that the extraction works - for quality reasons. 

From a COSHH or other health and safety legal perpective the marginal cost of doing what is required for operational reasons is also NIL - and so is "reasonably practicable".

The situation is entirely different if the extraction is put in for a mix of reasons. But, on the basis of the original posting the extraction is there only for production reasons - enhanced worker protection is a free benefit in terms of both installation and whatever maintenance, inspection, testing etc is considered appropriate and the COSHH assessment can be framed to reflect this. 

However, what is probably more important is an Operations and Maintenance Manual for the equipment - for quality reasons.