HAZARDS FROM LOW OR HIGH PRESSURE SYSTEMS

Preview This section discusses the hazards associated with laboratory equipment at either low or high pressures. 

When planning chemical synthesis work, the presence of a sealed system should be viewed as a trigger for additional safety review. 

A laboratory worker was conducting a routine filtration using a standard Erlenmeyer flask with a sidearm connected to a house vacuum system. The flask imploded and dispersed a spray of shards of glass and the solution being filtered. Fortunately, the filtration was in a chemical hood with the shield lowered and there were no injuries. 

INCIDENT 5.3.4.2 GLASS HAZARDS FROM A ROTARY EVAPORATOR  

A graduate student was using a rotary evaporator to remove solvent from a product. The student attempted to disconnect the round bottom flask from the ground glass joint of the vapor tube of the rotary evaporator but found it was stuck. As pressure and torque was applied the tube broke off just above the male fitting of the vapor tube. The sharp edges remaining on the rotary evaporator apparatus, cut the back of the hand above the thumb and several stitches were required to treat the wound. 

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CHAPTER 5 HAZARDS FROM LOW OR HIGH PRESSURE SYSTEMS... 

Reverse Flow can create high-consequence hazards because it can lead to the mixing of incompatible chemicals or to the introduction of corrosive chemicals into equipment not designed for them. The cause of Reverse Flow is usually a pressure reversal — a high-pressure section of the process loses pressure process fluids then flow into that section back from low-pressure sections of the process. (The occurrence of reverse flow almost invariably imphes that a check valve and/ or safety instrumented system has failed to prevent the event)... 

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