But the contractor hit back insisting the machines were used only to sell safety equipment to subcontractors who had forgotten their kit.

Martin Oldfield, health & safety manager for Barr Construction said: “Health and safety is Barr Construction’s number one priority.

“As an employer which takes the safety of its personnel extremely seriously, Barr provides PPE to its workforce free of charge as a matter of course.

“On sites where subcontractors make up part of our team, the onus is on these companies to provide their own staff with suitable PPE.

“In the past, there have been rare occurrences where subcontractor operatives have arrived on site with incomplete PPE or have needed to replace substandard safety equipment.

“The PPE vending machine has been provided as part of a trial to cater for these few instances and thus remove the need to leave site to collect replacement kit.

“Barr Construction insists that subcontractors provide all site operatives with appropriate safety equipment.

“The pilot vending initiative has been introduced as an added safety net to guarantee standard PPE is always available within the site area.”

Steve Murphy, General Secretary of Ucatt, said: “Ucatt officials all too frequently have to deal with companies and agencies who try to avoid their responsibility to supply the correct PPE. The failure to supply the correct PPE compromises workers’ safety.

“Poorly fitting PPE is almost as dangerous as not having the correct equipment. Companies must take safety seriously and ensure that the right PPE is supplied.”