During a visit to my local garage to have a suspicious noise in the car checked out, I noticed in the workshop what looked like one of our general purpose COSHH storage cabinets. The doors to the cabinet were partly open – which they should not have been under the Control of Substances Hazardous to Health (COSHH) Regulations 2002. Idling my time whilst the mechanic did his thing I took a sly look inside. In my partial view I saw some battery acid, solvent cleaning fluid and a couple of cans of oil plus a load of other cans and bottles in the darker recesses the contents of which I could only guess at.
Mindful not to aggravate the owner and risk my usual discount I said nothing but the incident did raise issues regarding the basic understanding of the regulations regarding the storage of hazardous substances.
It is true that a COSHH rated cabinet is perfectly acceptable for storing some dangerous substances. Although the operative words in the COSHH acronym are “Hazardous to Health” not all dangerous substances are necessarily so. So why do we have specific cabinets for Flammable Substances, Acids, Pesticides and so on? What the Garage owner clearly did not grasp were the H & S guidelines and regulations embodied within COSHH, REACH, DSEAR and the raft of UK and EU fire and safety legislation regarding the requirement to segregate and clearly identify incompatible hazardous substance in the workplace.
In addition when necessary the specialist substance Storage Cabinets include design features intended to enhance the security and protection afforded for the potential hazard of that specific substance. For example Flammables Storage Cabinets have sumps and spill trays and fully rebated doors to prevent flame ingress, pesticide cabinets have louvered vents to prevent fume accumulation, acid and alkali cabinets have zinc coated steel to reduce corrosion.
Acid/Alkali Hazardous storage cabinets demonstrate the issue of segregation very well. From the description you may think you can store acids and alkalis together in one of these cabinets. The opposite is the case. Acids and Caustic Alkalis are incompatible substances as they can create toxic fumes and even explosions when mixed. You should also separate acids from flammables, oils and grease, caustics from epoxies, ammonia from bleach and oxidisers from virtually everything else.
Accepting that few garage owners are qualified chemists it is understandably difficult to know what is acceptable storage practice. In general you should start by looking at the product label and hazard classification as guidance is more often than not given. If guidance is absent you should ask the supplier for the official data sheet.
As a guide you can view a general chemical compatibility chart in our advice centre but if in any doubt consult your nearest Health and Safety Department or an experienced H&S adviser.