A liquid nitrogen leak was reported in the early hours of this morning at the base of a firm that provides aerospace and defence systems to international space programmes.
Six fire engines rushed to the United Technologies Corporation centre in Maylands Avenue, Hemel Hempstead, just after 2.40am.
A 100-metre cordon was drawn around the leak, which firefighters said was coming from the valve of an 8,000-litre liquid nitrogen tank.
An engineer was called out to isolate the leak and the area was made safe by just before 4.40am. The building where it all happened is shared by communications firm Kcom.
The cause of the leak has not yet been established and United Technologies Corporation worker Martin Phillips said he could not comment on the incident.
He said: “We are in the middle of doing our own alternative investigation of what did happen.”
The firm describes itself as ‘one of the world’s largest suppliers of technologically advanced aerospace and defence products’ on its website.
The website says: “We design, manufacture and service systems and components and provide integrated solutions for commercial, regional, business and military aircraft, helicopters and other platforms.
“We are also a major supplier to international space programmes.”