Explosion safety rarely fails within the zone — it often fails between disciplines
In many companies, explosion safety is still treated too much as a formal compliance exercise. There is a hazardous area classification, an explosion protection document, selected Ex equipment, and at first sight the file appears to be complete.
In practice, however, safety is not created by documents alone. Safety is created through the interaction between the process, the installation, work equipment, human behaviour, maintenance, inspection, management of change and technical ownership.
A hazardous area zone indicates where an explosive atmosphere may occur. The more important question is what happens next. What is the underlying source of release? How does the scenario develop over time? Is the ventilation actually available when it is needed? Can a control-system failure lead to pressure build-up, product release, dust dispersion or failure of a protective measure? And is the originally selected type of protection still suitable after years of operation, maintenance, modifications and ageing?
That is why a professional explosion safety assessment must go beyond hazardous area classification alone. The ignition hazard assessment must reflect the real operating conditions and should be aligned with EN 1127-1 and the relevant explosion protection principles. Inspection and maintenance must take account of EN IEC 60079-17. New installations, modifications and extensions must be assessed from the perspective of design, selection, erection and initial inspection in accordance with EN IEC 60079-14. Where machinery forms part of the process, machinery safety becomes an essential part of the overall assessment.
This interface will become even more important towards 2027. In the European Union, Regulation (EU) 2023/1230 on machinery will place stronger emphasis on machinery, partly completed machinery, assemblies of machinery, substantial modifications, safety functions, software, control systems and responsibilities throughout the supply chain. In explosive atmospheres, a machine can therefore not be assessed in isolation. It must be assessed in the context of the potentially explosive atmosphere, the possible ignition sources and the operational protective measures.
For the United Kingdom, the same technical logic applies, although the legal framework is different. Workplace explosion safety is primarily addressed through DSEAR, while equipment and protective systems intended for use in potentially explosive atmospheres are covered by the UK regulations for such equipment. In addition, PUWER remains relevant where work equipment and machinery are used, maintained or modified. The legal terminology may differ between the EU and the UK, but the technical question remains the same: is the installation safe in its real operating context?
This is where HAZOP, LOPA and SIL provide real value. Not as fashionable terminology, but as tools to make process scenarios technically understandable. A deviation such as higher temperature, lower flow, pressure increase, loss of inerting or insufficient extraction is rarely a single event. More often, it is a developing chain. Only when that chain is understood can we determine which protective layers are actually required and whether they are independent, reliable and demonstrably effective.
Explosion safety therefore requires an integrated approach:
from source of release to hazardous area classification;
from hazardous area classification to ignition hazard assessment;
from ignition hazard assessment to the selection of suitable equipment and protective systems;
from selection to correct installation;
from inspection to safe operation;
from modification to reassessment;
from scenario development to demonstrable risk reduction.
Experience from industrial installations shows that the danger is not only in the gas, vapour, mist or dust that may be present. The danger is often in the blind spot between disciplines.
Process safety, explosion safety, machinery safety and functional safety should therefore not exist as separate files next to each other. They must be technically connected.
Because a potentially explosive atmosphere does not need a tick in a checklist.
It requires technical understanding.
#ATEX #ExplosionSafety #MachinerySafety #HAZOP #LOPA #SIL #DSEAR #UKCA #ProcessSafety