In Biffa v Outokumpu [2008] EWCA Civ 1238 the dispute arose after a fire was started as a result of welding work being carried out by employees of the second Defendant.  

The first question for the Court of Appeal was whether an employer can be held vicariously liable for the actions of an occasional employee, who is an employee of an independent contractor but who becomes the employer’s borrowed employee.  

The second question that was whether a defendant can be held liable for the negligence of his independent contractor when the activities of the independent contractor are ultra hazardous.  

In the lower court (the TCC), the judge made an exception to the normal rule that a defendant may only be held vicariously liable for the acts of his officers or employees and is not liable for the acts of independent contractors. He held that the second Defendant contractor (applicant in this case) based in Sweden was liable for the actions of welders employed by sub-contractors working at a plant in England over which a third party had supervision.  

The Court of Appeal allowed the appeal and opined that it would be “curious” to hold a company in Sweden liable, without negligence on its part, for the welding work carried out in England by skilled welders employed by an independent sub-contractor, on a site at which a third company was generally responsible for safety