Why in India height work is considered above 1.8 mtr?

A fall from what height can cause severe injury or fatality.

A fall from 0.3 meters to 1.2 meters seldom results in fatality however falls from a height of 1.8 meters mostly results in severe head injuries and fatality. One can easily conclude that over 1.8 meters we need fall protection and it is as simple as that.

Now the regulation vary from country to country in India it is over 3 meters in USA as per OSHA for general industry it is over 1.2 meters and in construction 1.8 meters.

Because that height is already considered a fall danger.