ISO 15012-4:2016 defines the general requirements for ventilation equipment used to control exposure to fumes generated by welding and allied processes. It applies to the design and manufacture of all parts of the equipment including hoods, ducting, filter units, air movers, systems that inform of unsafe operation and workplace practices to ensure safe working with regard to exposure.Significant hazards are listed in Clause 4. It does not cover electrical, mechanical and pneumatic hazards.ISO 15012-4:2016 is applicable to the following:- local exhaust ventilation systems (LEV);- mobile and stationary equipment.It is not applicable to the following:- general ventilation, air make up or air movement systems;- air conditioning systems;- separation of gases generated by or used by welding and allied processes;- LEV used for welding and allied processes that generate reactive potentially explosive particles and atmospheres;- grinding dust.ISO 15012-4:2016 applies to systems designed and manufactured after its publication.