A Hackney Homes worker suffered head and shoulder injuries after a stranger unexpectedly poured what is believed to be drain cleaner over his head yesterday.

The 53-year old victim was mowing the lawn at the Kier Hardy Estate in Springfield Road, Upper Clapton last Wednesday when a woman unexpectedly threw the mystery substance at him.

Drain cleaners are designed to eat through any material which is clogging up pipes, and for this reason are extremely dangerous if they come in contact with human skin. Strongly corrosive and acidic, they can burn the skin and lead to necrosis of the skin and tissues underneath.

The man was discharged from hospital last night.

A 53-year-old woman has been arrested on suspicion of grievous bodily harm and remains in custody at an east London police station.

Police say the victim and suspect are not known to each other.

Charlotte Graves, chief executive of Hackney Homes, said: “We will not tolerate assaults on our staff and we will always take the strongest possible action against those who carry them out.

“We are working closely with police who are investigating the incident.”