Inside Kolkata's tanneries - in pictures

A boy plays on a scooter up the road from a leather goods workshop Photograph: Piyal Adhikary/EPA

A welcome wash after a day's labour at the Kolkata Leather Complex where hundreds of tanners work Photograph: Piyal Adhikary/EPA

A labourer washes buffalo leather with a salt solution Photograph: Piyal Adhikary/EPA

Plastic bags and sheets are used to protect against harmful chemicals Photograph: Piyal Adhikary/EPA

Rafik Muhammad seals the opening to a huge leather treatment tank Photograph: Piyal Adhikary/EPA

The tanneries are mostly run by families living and working under poor conditions Photograph: Piyal Adhikary/EPA

Leather pieces are worked on in an alleyway outside a tannery Photograph: Piyal Adhikary/EPA

Sheikh Abdul Hakim reads from the Qur'an at his shop-cum-primary school near a leather workshop. The sheikh runs a free school for children of poor tannery workers Photograph: Piyal Adhikary/EPA

Children of families who cannot afford the government schools attend classes at privately run free schools Photograph: Piyal Adhikary/EPA

Hanif Muhammad washes chemicals off his legs after a process called 'fleshing'. It is one of the several stages of the tanning process where subcutaneous material is removed from raw leather Photograph: Piyal Adhikary/EPA

Hassan Malik works in a leather shoe factory at Topsia Photograph: Piyal Adhikary/EPA

Wet leather dries in the sun on the roof of a tannery workshop Photograph: Piyal Adhikary/EPA