Amid the relentless clatter of machinery, Ravi Kumar Gupta feeds a roaring steel furnace with scrap, blown metal and molten iron. He carefully adds chemicals tailored to the type of steel being produced, adjusting fuel and airflow with precision to keep the furnace running smoothly.

As his shift ends about 4pm, he stops briefly at a roadside tea shop just outside the gates of the steel factory in Maharashtra state’s Tarapur Industrial Area. His safety helmet is still on, but his feet, instead of being shielded by boots, are in worn-out slippers – scant protection against the molten metal he works with. His eyes are bloodshot with exhaustion, and his green, full-sleeved shirt and faded, torn blue jeans are stained with grease and sweat. Four years after migrating from Barabanki, a district in the northern Indian state of Uttar Pradesh, Ravi earns $175 per month – $25 less than India’s monthly per capita income. And the paycheques are often delayed, arriving only between the 10th and 12th of each month.