Emergency services have flooded Gallions Road today (December 16) following reports of the incident at around 9.30am.
Greenwich councillor David Gardner has claimed that this has taken place near the Marks & Spencer store.
The London Ambulance Service said 30 people were treated for chemical inhalation.
It has also said that a number of resources were sent, including specialists from its hazardous area response team, advanced paramedic practitioners and conventional ambulances.
James Johnson, Strategic Commander for the London Ambulance Service, said: “The incident is ongoing and we are working with our emergency services partners to manage this incident and continue to deliver service in the rest of London.”
A London Fire Brigade spokesperson said: “Firefighters are currently at the scene of a suspected carbon monoxide incident at a shop on Gallions Road in Charlton.
“Crews are working alongside multi-agency partners to resolve the incident safely.
“The Brigade was called at 0835 and two fire engines and two fire rescue units are at the scene.”
Marks & Spencer has been approached for comment.
