Two were taken to hospital for treatment amid a major emergency response at Bourne House at Belbins Business Park in Romsey.
The workers – who suffered from headaches and severe nausea – had collected items on their round but when put in their lorry this reacted and created chlorine.
They returned to their depot at Bourne House where firefighters, police and paramedics attended with the ambulance services’ Hazardous Area Response Team.
“As the nature of the chemical was initially unknown, the team returned to their base at Bourne House and called the fire service and ambulance.”
He said the contaminated items were being cleared yesterday afternoon.
People at the industrial estate were shocked by the incident on Thursday.
Mat Pinner, from North Baddesley, told the Echo: “I only realised that something had happened when I tried to get in to the industrial estate and couldn’t.
“I saw the emergency services and thought something serious must have happened. I hope those that have been injured are doing ok.”
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One worker, who wished to remain unnamed, said: “We were a car park for the emergency services, but the whole situation was well organised.
“We didn’t know anyone was injured until we read the Echo.”
A person who works in the estate, who did not want to be named, added: “I saw all the emergency vehicles but had no idea what was happening.
“I can’t believe three people are injured, I hope they recover.”
Firefighters were called in at around 9am on Thursday, with the incident over by 10.52am.
An ambulance service spokesman said: “We received a 999 call at 8.49am who reported that three people working on a rubbish lorry had become unwell when exposed to an unknown substance whilst emptying some bins on Belbins Business Park, Romsey.
“Hampshire police and Hampshire Fire and Rescue Service also responded to the incident.
“We sent our full Hazardous Area Response Team, a paramedic team leader in a rapid response vehicle and two ambulances to the scene.”
