NEBOSH Diploma Syllabus Revision News #23


This brings us to element C4 in Unit C.  The older people amongst you will probably be reminded of the popular plastic explosives that was the favourite of many a 1980’s action movie.   Well, as it turns out this element is on the storage and handling of dangerous substances.  You may also notice a good deal of overlap with other NEBOSH qualifications like the International Technical Certificate in Oil and Gas and the Process Safety Award.  That’s because these are high hazard process industry issues – oil and gas and chemical manufacturing being examples of these.  These industries have a history of rare but spectacular accidents.  Partly this is because of the complexity of the processes they operate, combined with the intolerance of the substances they use.  The products they manufacture or process or act as raw materials for are of immense use to mankind (like fuels for our cars and homes, plastics, pharmaceuticals and so on) and they are a major employer.  So, society would have a melt-down if these operations were shut-down overnight because they were “too risky”.  Instead, they have to be managed.  Because of the issues I already mentioned about these processes, it turns out attention to seemingly little things (like corrosion, maintenance, procedures) as well as bigger things, has impact well beyond what you’d expect.  So, just looking at traditional personal safety (like accident rates, wearing PPE etc) doesn’t get you very far – the plant could be steadily corroding after years of neglect, the temperature and pressure gauges could be faulty and the next time you use the plant to make product X, the slight over-temperature and overpressure causes a thermal runaway reaction, destroys the mix vessel/tank, spewing toxic and flammable vapour everywhere.  This then ignites and causes adjacent plant (which happens to be far too close) to blow up too.  The toxic cloud drifts to the neighbouring residential area – schools and hospitals.  You think it’ll never happen in your lifetime of course, so why spend the money on process safety to try to make it even less likely?

This element hasn’t changed much – it’s about process safety.  That’s safety applied to high hazard process industries to specifically try to avert major accidents such as large scale toxic release, fire and explosion.  Process industries adopt a ‘layers of protection’ approach.  They know that these accidents occur due to a whole series of issues coming together at the same time.  They also know that no safety control is 100% effective 100% of the time.  Hence multiple layers or barriers.  At the top of the chain is thoroughly understanding your process and what could go wrong – how bad and how likely.  On top of that you’ll need systems for identifying issues before they become big (active monitoring, including detection equipment); rigorous controls and procedures for processes and equipment (to make sure they are always operated within design parameters and, importantly, any changes are thought through properly); emergency shut-down when things are about to go wrong;  emergency plans and equipment to stop a small event from escalating into a far bigger events (or a big event from getting even bigger).  If you think it’ll never happen and you’re doing nothing except filling in paperwork and handing out hard hats, then you’re probably already complacent and sooner or later it will happen.