The fire was finally brought under control after four hours by eight crews from the Essex Fire and Rescue Service.
The blaze has destroyed the C&B Techniques factory in Redstock Road.
Assistant Divisional Officer Neil Fenwick, incident commander, said: “When crews first arrived they were confronted with a well developed and quickly spreading fire in the ground floor of the factory.
“The unit is used as a woodwork factory and the nature of the business has meant that there is a great deal of flammable material inside the factory including wood, sawdust and various chemicals used by the joiners.
“The first crews to arrive quickly escalated the incident and we now have nine appliances tackling the fire.
“Crews have battled hard and hove done an excellent job in containing the fire. Because of all the wood in the unit it has been a fiercely burring blaze and it is thanks to crews hard work and professionalism that the fire has been contained to the factory where it started.
“We are now on top of the fire and have it surrounded although it will continue to burn for some time and crews will be working on site for hours to come yet.”