Oil bath
A means of heating samples to temperatures higher than 100°C, the theoretical limit of a water bath, and lower than approximately 200°C. This limit is the safety limit recommended by the companies supplying the oil and must NOT be exceeded.
Samples are placed in containers filled with oil which is heated on an electric hotplate equipped with a thermostat. The temperature of the bath must be carefully controlled. The aluminium foil serves to protect the hotplate from oil which, if spilt, burns on the hotplate and give rise to toxic fumes.
It is advisable to wear safety glasses and to put the oil bath in a well-ventilated fume cupboard.
A oil bath should be used instead of a water bath when the reagents or products in a reaction are likely to react violently with water.