We work in a laboratory with 600 volt electrical disconnects (both fused and non-fused) inside the building. For this reason we are being told to wear long sleeve, 100% cotton shirts 12 months per year. Can anyone tell me if this is actually an OSHA requirement, or simply an over reaction by our company.

I would like to know a summary of the requirements for wearing long sleeve shirts.

In my opinion, your company should do an arc flash study to determine the energy at these disconnects. If what is called (IE) or incident energy calculates to a value greater than 1.2 then your employer is protecting you. Then on the other side if the hazard is really high then the long sleeve cotton will not protect you either. You would need FR colthing in the first place but 100% cotton is better then other materials. Ultimately, I suppose your employer can make just about any policy that you have to live with.

The LS cotton shirt is part of the lowest arc flash PPE requirement, called HRC 0. If you are "interacting" with this equipment, meaning at the very least opening or closing them, you need to wear the LS shirt, and yes, non melting LS shirts have been an OSHA requirement since 1971.

However, if you really follow the NFPA 70E (Which OSHA currently enforces through it's general duty clause) , you most likely will need more protection, including FR clothing rated for either the calulated Ei or per the NFPA 70E tables.

If anything, your company is under-reacting.

The Technicians should not be opening the electrical equipment, we have an equipment group to take care of any electrical repairs in the lab. They are required to open/close the throw switch, but I'm guessing a jacket could be worn for that? Also, we have already had an arc flash study completed. Our worst case scenario is 0.50 cal/cm in the lab.

Then they need to wear HRC O, which includes a LS non melting shirt.

Your employer can pretty much tell you what to wear, but if they require specific apparel, then they may be required to purchase it. That's a bit of a gray area and you can decide how far to push it.

As to your question, there's a discussion about whether PPE is required when the equipment doors are fully latched. It's very clear that when the door is open, that PPE is required. However, a reading of FPN1 under the definition of arc flash hazard leaves room for interpretation of whether a hazard exists when operating equipment in a normal way when it has been properly maintained. So if the equipment meets that criteria, then you may not be required to have any PPE on. However, it is safer to have some sort of protection. You might suggest to your supervisors that they provide a jacket and leather gloves for use when operating the switches and you (the employees operating the equipment) will agree to wear 100% natural fibers under that jacket. This is a safe compromise that goes beyond the requirements but provides good safety.

In addition to the PPE, your employer is responsible for training you in the hazards of operating the switches and the proper way to do it.

It may have nothing to do with the electrical work. Its not unusual to mandate long sleeve clothes where ever strong acids and bases are employed. It may just be for spill protection.