The news of resignation of Pope Benedict XVI on 28^th February 2013 shook the world. This was the second resignation by a Pope after Pope Gregory XII in 1415 or call it third considering the first as Pope Celestine V relinquished responsibilities in December 1294.

The subsequent election of Pope Francis in 2013 was widely covered by news media across the globe. We all know that the Papal Conclave sealed in Sistine Chapel do the election of new pope after expelling the outsiders, done by the Master of the Papal Liturgical Celebrations calling out: “Extra omnes!” (“Everybody else, out!”).

The believers and everyone else present in St. Peters Square and those who watch the live telecast breathtakingly wait for the sign of new Pope being elected with the colour of the smoke signal.

If the papal election is not decisive the papal conclave sends out the message through black smoke (fumata nera) and when the pope is elected it is declared through white smoke (fumata bianca).

How do papal conclave produce these black and white smoke?                                                            

• Black smoke (fumata nera) is produced by burning Potassium Perchlorate + Anthracene + Sulphur   

• White smoke (fumata bianca) is produced by burning Potassium Chlorate + Lactose + Rosin

Both Potassium Perchlorate and Potassium Chlorate are classified as oxidizing substances, Class 5.1, in  dangerous goods regulations. Potassium Chlorate is assigned with United Nations identification number 1485 and Potassium Perchlorate with 1489. The entries of both these substances contain observation reading “White crystals or powder. Soluble in water. Reacts vigorously with sulphuric acid. Reacts fiercely with cyanides when heated or by friction. May form explosive mixtures with combustible material, powdered metals or ammonium compounds. These mixtures are sensitive to friction and are liable to ignite. When involved in a fire, may cause an explosion.”