Answer: The ISI mark is mandatory for certifying products to be sold in India, like many of the electrical appliances viz; switches, electric motors, wiring cables, heaters, kitchen appliances etc., and other products like Portland cement, LPG valves, LPG cylinders, automotive tyres etc. But in the case of most other products it is voluntary......
Explanation: It is not compulsory for all the producers to follow such standards and get certificates. Products which largely effects health and safety of consumers or which are of mass consumption it is mandatory on the part of the producers to get certified by these organisations.