1910.303(g)(2)(i)
Except as required or permitted elsewhere in this subpart, live parts of electric equipment operating at 50 volts or more shall be guarded against accidental contact by approved cabinets or other forms of approved enclosures, or by any of the following means...

Then in
OSHA 1910.137 Electrical Protective Equipment
(a) Note: Rubber insulating equipment meeting the following national consensus standards is deemed to be in compliance with paragraph (a) of this section:
ASTM D120 Specification for Rubber Insulating Gloves

OSHA 1910.269 Electric Power Generation, Transmission, and Distribution
(l) Working on or near exposed energized parts
(2) Minimum approach distances. The employer shall ensure that no employee approaches or takes any conductive object closer to exposed energized parts than set forth in Table R-6 through Table R-10 unless:

(i) The employee is insulated from the energized part (insulating gloves or insulating gloves and sleeves worn in accordance with paragraph (l)(3) of this section are considered insulation of the employee only with regard to the energized part upon which work is being performed),...

Table R-6 excerpted
Table R-6. - AC Live-Line Work Minimum Approach Distance

"8.7.4 Protector gloves may be omitted for Class 0 gloves, under limited use conditions, where small equipment and parts manipulation require unusually good finger dexterity. Under the same conditions, Class 00 gloves may be used without protectors, but only at voltages up to and including 250 V ac. ..."

Your Question 3
Is there a NIOSH approved respirator for use with a beard?

STG Answer
According to OSHA 29CFR1910.134, all negative pressure respirators must be fit-tested to confirm the mask-to-face seal. Obviously the presence of any facial hair could affect the quality of the seal. If that is the case, then the only NIOSH-approved respirators suitable for use would be continuous flow supplied air respirators with a full hood. The key is whether the facial hair interferes with the tight-fitting seal of the respirator.

You can find more details on line from OSHA at http://www.osha.gov/SLTC/respiratory_advisor/oshafiles/fittesting1.html

Your Question 4
Cam you can get a fit test with SCBA with facial hair. Can you wear a SCBA?

STG Answer
Per OSHA, ANSI, NFPA and North instructions...no respirator (including positive pressure respirators) should be used when facial hair interferes with the face seal.

OSHA's requirement 29 CFR 1901.134 (g)(1) Facepiece seal protection. (i) The employer shall not permit respirators with tight-fitting facepieces to be worn by employees who have: (A) Facial hair that comes between the sealing surface of the facepiece and the face or that interferes with valve function;

ANSI Z88.2-1992 7.5.1 Facial Hair A respirator, either positive or negative pressure, equipped with a facepiece (tight or loose fitting) shall not be worn if the facial hair comes between the facepiece and the face or if facial hair interferes with valve function.

NFPA 1500 5-3.9 A growth of beard or facial hair at any point where the SCBA facepiece is designed to seal with the face, regardless of the specific fit test measurement that can be obtained, or hair that could interfere with the facepiece valve function shall be prohibited for members required to use SCBA