Posted By neil cannell Scenario, Small analytical laboratory, open plan ground floor with stairs which lead from the edge of the lab desks, to an open plan upper mezzanine floor. My concern is although large quantities of dangerous chemicals are not used in this area, there may be some that if containers were broken would require evacuation of area including mezzanine which would need to be evacuated down the only set of stairs past where the chemicals may have been spilled. Good managers willing to listen want to do right thing. All lab workers are trained chemists very competent. Chemical type used bromine type so small release could mean evacuation. Risk assessment results, could be • Remove substitute chemicals, awkward, after all it is a lab, • Removal of process’s that might result in fumes being released to separate rooms • Engineered, open plan access removed lab area contained in separate room (open plan designed to create greater worker comfort) • LEV, fume covers • If possible secondary exit from mezzanine, difficult, expensive Have not considered escape sets for upstairs, upstairs used as canteen meeting room, storage Opinions please

Posted By Konstanty Budkiewicz Neil, In support of the earlier posting. Can we assume that: a. you have a minumum of 6 air changes per hour in the lab? and b. that negative pressure is maintained in relation to the higher-level less hazardous area? and c. High level air input and low level extract? Kon, CMIOSH

Posted By neil cannell Kon As i understand it no, the original lab area had the mezzanine added, the ventilation system is work in progress

Posted By neil cannell thanks jane The systems in place ,use of small quantities fume cuboards, ppe, safe systems, training are almost certainly the same as used all over the country, and in a normal lab would be fine, the presence of an open plan lab with mezzanine is what i feel is complicating the issue. The need to either avoid, or plan for emergency procedures,(for this problem) together with preventing the inevitable release of fumes to the upstairs level is what i am looking for. neil

Posted By neil cannell jane sorry if its confusing, Open plan by virtue of the fact that the mezzanine overlooks the lab area. There are fume cupboard's on the exterior walls, but the main work bench area is open plan. Chemicals are transported to and from this area as safely as possible but there is always a chance of breakage and it is this chance that i am concerned with, ie people upstairs escaping through fumes as the stairs from upstairs terminate at the edge of the work station area.

Posted By Colin Reeves Not sure of the layout, but if the staircase to the mezzanine is along a wall, could this not be partitioned off to form a corridor to an escape door. Then, so long as the pressure in the mezzanine / stairway was positive this would remove that whole area from concern. Colin

Posted By Konstanty Budkiewicz Neil, I Googled your problem and suggest that you invest £150 for the following document: BS ISO 15190:2003 Medical laboratories. Requirements for safety. Armed with this you should be able to conduct a gap analysis, as implied by Jane earlier. You would then be in a position to conduct a valid risk assessment and seek a resolution of any emerging issues. Kon