The public is being warned a contingency plan is in place to protect them as up to 900 firefighters go on strike.
The walkout in Essex is over proposed cuts, staffing levels and working conditions.
The county's fire and rescue service says more than one hundred firefighters are still working.
The first in a series of five strikes involving firefighters is taking place today.
The Fire Brigades Union in Essex claims the county will have lost one in five frontline staff since 2008 if cuts go ahead.
But service managers insist jobs are safe and say one hundred firefighters and retained crews will step in during the industrial action.
Firefighters in Essex will today hold the first of five planned strikes in a dispute over cuts.
The Fire Brigades Union said its members plan to take industrial action today and on July 7 and 18, August 18 and October 18. Today's strike is due to start at 10am and end at 6pm.