An environmental health investigation is ongoing at the Ilford branch of Primark after suspected paint fumes made people faint.

Ambulance crews treated 11 people for dizziness, headaches and fainting and took four to hospital after mysterious fumes spread through the shop in High Road, Ilford on Tuesday.

London Ambulance Service sent its hazardous area response at about 11.30am and police helped with the evacuation at 12.45pm.

Redbridge police inspector Paul Vear said contractors had been doing some painting on the ceiling of the new shop, which opened last month.

“Paint fumes have come through the building. They made 11 people unwell. There were a lot of people to get out, the shop was busy,” he said.

A Primark worker, who did not want to be named, said staff members were “collapsing on the stairs”.

“Everyone was feeling dizzy and getting headaches.

“One person was talking to me and just fainted in front of me, I was really worried. One of our supervisors was really bad – he was shaking.”

Shopper Claire Giemajner visited the shop during her lunch break and told the Recorder she still felt like she was going to pass out 24 hours later.“From the minute I went in there I felt ill, I was only in there for 15 minutes and I’ve been feeling ill ever since,” she said.

Redbridge Council senior environmental officer John Eva said: “We understand there has been some work going on on the roof and the air conditioning sucked in the fumes. We have launched an investigation.”

Shoppers formed a large crowd outside the shop during and after the evacuation while traffic was disrupted by emergency vehicles.

A Primark spokeswoman said “Primark takes any inicident within its stores seriously and is in the process of carrying out a full investigation at the Ilford store.

“Customer safety is a priority and as a Health and Safety precaution an evacuation was undertaken”.