Designing and operating safe chemical reaction processes HSG143

Health and SafetyExecutive184 Other examples include:(a) increases in process temperature - these may accelerate an exothermicreaction, increase reactor vapour pressure, cause thermal decomposition,or simply reduce the time available for corrective action;(b) decreases in process temperature - these may cause unreacted material toaccumulate (this can be a particular problem in addition controlled semi-batchreactions);(c) changes in raw material specification - these can introduce unexpected sidereactions;(d) concentration changes - these can change the rate of reaction;(e) increases in cycle process time - these may give a thermally unstable materialtime to decompose; and(f) replacement of metal pipes or piping components by plastic ones - staticelectricity may build up and ignite flammable materials.185 Make sure that you assess the effect of the modification on the original basisof safety. If the change affects the basis of safety then you should initiate a furtherassessment. All modifications should be fully documented.Operator training186 Adequate training and knowledge of the properties of the materials handledare essential for safe operations. Training is a requirement of the MHSWRegulations. 2 Carrying out the risk assessments required by these Regulationswill identify how much information, training and retraining is needed. An ApprovedCode of Practice 40 gives further guidance on these Regulations. HSE has produceda leaflet concerning training and identifying training needs. 41187 You need to inform all staff (including contractors, etc) who are on the site ofthe hazards of handling the materials involved, in operating the process, and theprecautions they need to take to ensure safety. Those directly responsible for theoperations should also receive specific training in emergency procedures. Periodicretraining will normally be required. The training should include the followingaspects:(a) the types of materials handled, their properties and hazards;(b) general procedures for safe handling;(c) use of PPE and clothing;(d) the need for good housekeeping;(e) reporting procedures for faults and incidents, including minor leaks and spills;and(f) emergency procedures, including raising the alarm, calling the emergencyservices and the use of appropriate emergency equipment.Designing and operating safe chemical reaction processes Page 35 of 64