Following an inspection by the Health and Safety Executive (HSE), the Waltham Forest-based company was also forced to pay £5,250 in costs.
Delta Display was fined following an incident when vapours from a flammable cleaning fluid ignited in a print room.
The two printers suffered burns and one suffered serious breaks to both legs as he tried to escape the fire. One of them described the explosion and fire as a ‘flamethrower’ coming from the top of the printing press.
The HSE carried out an investigation into the incident, which occurred on 20 May 2011, and found the company had ignored the press manufacturer's guidance that there was a danger of fire and explosion if any cleaning agent with a flash point below 55 degrees centigrade was used.
On Wednesday (9 May) Westminster Magistrates’ Court heard that the two men had been using the solvent provided to hand-clean the ‘blankets’ of a printing press, a regular task to clear the build-up of ink. The solvent, called QE3, had a flash point of -20 degrees centigrade.
They had completed part of the process when one of them saw a flash in front of his eyes and the fire started. He jumped from the press over a safety rail to escape, shattering his left ankle, fracturing his right heel and sustaining burns to his right calf and left arm.
This employee was in hospital for 15 days and initially off work for four months. He had two operations and is currently undergoing physiotherapy following the second.
The other employee received burns to his arms but was back at work soon after the incident.
HSE Inspector Chris Tilley said: "These two men have suffered serious and painful injuries because Delta Display did not heed the guidance from the manufacturers of the printing press.
"The risks from flammable substances are well known in industry as are the relevant preventative measures. In this case, if the company had completed a sufficient risk assessment they would have identified that using QE3 solvent as a cleaning agent with this type of press was dangerous and could have substituted it for a safer cleaning material.
"The company introduced a safer alternative days after the incident but made little effort beforehand to consider the risks and put a system of work in place that would better protect their workers."
