Worked in a place where FRC was mandatory. Tank cleaners had to wear the FRC, Yellow Tyvek, and a rain suit. Even with the ice vest 10 minutes and they had to come out. Location would not let the crew work at night and temp inside the tank would hit 150F by 3 pm.Crew would be in 10 out 10 in 10 and out 30. Would change the ice packs after the second come out. It was so hot outside the tank during rest periods the guys would keep the vest on.
Safety was stupid on this job. I was the entry supervisor and me and the shift safety got cross threaded because he wanted the guys to remove the vest during the 30 minute rest period. Got with the plant safety manager and got this straightened out. Pure, Plain, Miserable
The tethered ones don't work so pretty good for tank cleaning.