There are many publications on managing risks within small workshops such as railway arches or units at around 70sqm (o booths are used, just open plan spaces). However most contain conflicting information. As do advisors I have employed to date.

On the one hand, mechanical ventlation isn't required according to the Workplace health safety and welfare regs but then COSHH states "use exhaust ventilation to control exposure..."

Nobody asked so far has given me a definitive on whether ATEX or IP fittings are required. LPS is stored and used as are multiple chemicales, fillers, resisn etc so I would have thought these were a requirement which one advisor said they were and one has said there isn't. 

Fire protection? There is nothing in the regs which said a system is required, however, the HSE state that "a fire-resisting room" is required for paint mixing.

Just wondered if anyone had direct experience of having managed the safety in such a unit and what their advice would be

Roysta, not convinced that the publications tend to be contradictory - they just need to be read in full context.

COSHH doesn't say that extraction is or isn't required.

COSHH sets out some requirements to be achieved but does not prescribe how to achieve.

Guidance (sometimes with the quasi-legal status of e.g. an Approved Code of Practice) then takes typical industrial environments and advises on what might be appropriate. So, as example if there is spraying of solvent based paints, extraction is likely to be appropriate.

Exactly the same considerations apply to some of your other examples. A fire resistant area would not be required for the mixing of water-based paints.

So, perhaps you need to reframe your question if you want a sensible answer.

Sorry, maybe my post wasn't clear. What I am saying is that these units have been physically inspected by 3rd parties who have all been in receipt of full knowledge regarding exactly what substances are used, what welding and spraying activities are carried out and have looked at numbers of users, length of activities, exposure levels, storage, maintenance regimes; the whole picture in fact and have still come up with differing advice. All in all, 5 surveys and yet hardly any agree with each other on virtually anything! Literally looking through the reports side by side, there is very few areas agreed on. For clarity, one was an M&E consultant working for a international consultancy, one was a CDM consultant, one a RICS building surveyor, one was a CMIOSH member and the other a Project Manager involved with a multi-national hotel chain. The references I made have been lifted from the reports they issued! As an example, the CMIOSH guy said no mechanical extract was required and that natural ventilation was sufficient and quoted the WHSW regs, the M&E guy said not only did the same units need mechanical extract, it had to be horizontal extract to comply with DSEAR and Building Regs. The CDM guy suggests fire alarms may be required, the M&E guy said they definately are required and the CMIOSH guy said they definatley aren't required. The PM guy said leave the lead water pipes in as quote "there are thousands installed across the country", the CMIOSH guy said they should be removed quote "at the earliest opportunity" and replaced with plastic. We even have units with LPG with no segregation, no signage, no restraints yet the CMIOSH guy stated this as low risk (these guys have operating for years with no problems) yet all other reports state high risk!

I guess maybe there isn't a definative answer to these issues and much is open to interpretation and that ultimately I have to decide which bits of which report to implement! Shame I can't get a clear unambigous solution though.

If you ask five specialist experts a question you have to expect five different answers form the viewpoint of their expertise. Unfortunately your list reads like a rogues gallery but misses the key suspects who should have been involved:

a member of BOHS for workplace exposure and ventilation

a qualified Fire Risk Assessor 

On these forums where we all have a common specialism I am still waiting to read the RIDDOR thread when everyone agrees

I would say that you appear to be suffering both the advantage and disadvantage of the current h&s system. Instead of being prescriptive as much of h&s used to be, h&s law is now risk and objective based.

As you are no doubt now aware there is a legal requirement to conduct risk assessments - either spcifically under DSEAR/ATEX or COSHH legislation or the general requirement under the Management of H&S regs.

However, what you then do and what is proportionate to the hazards/risks of your business is then open to debate - as you have seen from the various reports you have at your desk.

Sadly nobody can be an expert in every h&s topic, which maybe partly explains the differing opinions you have as well as the obvious limitations of each persons area of knowledge/experience.

My main area of interest is DSEAR/ATEX - of which the HSE guidance L138 ACOP tells you what the regulations apply to and what you must consider under your risk assessment. However as previous what you then do depends.

If you do undertake painting with solvent based paints - do you spray paint or is it just hand/brush painting? Its imperitive that the process is understood. The controls for spray painting are very different to relatively low risk hand brush painting.

I'll stick my neck out - if you are in a small industrial unit and only hand painting - then provided you are in an open area with 'normal' venilation such as open doors/windows etc then any hazardous area is likely to be less than 1m. Therefore it is unlikely that you need special tools/electrical equipment (ATEX rated electrical equipment is only required if it is used inside the hazardous area).

For such small scale use it would be expected to see a 'flammable' storage locker in which to store paints/sovents, to a limit of 50litres. The locker should have at least 30minutes fire integrity. 

Other containers used to hold paint etc should be sealable/original containers and not fragile.

Ignition controls are the obvious - no smoking, no hot work nearby etc as part of your safe system of work

Paint spraying would be different - as obviously the paint vapours are likely to travel over a wider area. Working indside some form of enclosure is usual, with lighting mounted outside the enclosure where possible - otherwise Zone 1 lighting is likely, as usually all of the enclosure is likely to be a Zone 1 hazardous area.

Key guidance are HSE publications L138 Acop, HSG140, HSG51