• Distillation and heating under reflux must be carried out in fume cupboard if vapour of one of reactants or products is harmful, poisonous (toxic) or irritant
• If a mixture is being heated under reflux or distilled, there must be some outlet to the air or pressure will build up in apparatus and form airlock / bubbles
• Gloves must be worn when corrosive substances are used
• Flask should never be heated with Bunsen flame as almost all organic substances are flammable