1. (a) Where not effectively grounded and/or bonded by contact or connection, provision shall be made to prevent the accumulation of static electrical charges which may create a source of ignition in the presence of flammable vapors or gases. This order applies specifically, but is not necessarily limited to, the following operations:

   1. (1) Blowing or agitating with air.
   2. (2) Loading and unloading tank cars and tank trucks.
   3. (3) Filling metal drums or containers.
   4. (4) Abrasive Blasting.

   5. (5) Hydroblasting.

      Exception: Bonding is not required where vehicles are loaded or unloaded exclusively with products not having a static accumulating tendency.

2. (b) Stationary tanks containing flammable liquids and Class II combustible liquids, not inherently grounded by contact or by connection to a grounded pipe line, shall be grounded.

3. (c) The nozzle of air, high pressure water cleaning systems, grit cleaning systems, inert gas and steam lines or hoses when used in the cleaning or ventilation of tanks and vessels that contain hazardous concentrations of flammable gases or vapors, shall be grounded and bonded to the tank or vessel shell. Bonding devices shall not be attached nor detached in hazardous concentrations of flammable gases or vapors. Before starting work, precautions shall be taken to prevent ignition of flammable atmospheres in tanks and vessels in accordance with the requirements of Sections 5168 and 5420 of the General Industry Safety Orders.

   Exception: High pressure water cleaning system nozzles used to clean tanks or vessels 100 cubic meters or less in size need not be bonded to the tank or vessel shell, provided all conductive components are grounded and it is not possible for steam to enter the tank or vessel.

4. (d) Conductors used for bonding and grounding shall be equivalent in strength to a #8 A.W.G. (American Wire Gage) copper wire and shall be suitably conductive to ensure a circuit resistance of not more than one megohm.
5. (e) Flexible conductors shall be used for bonds that are to be connected and disconnected frequently. Solid conductors are acceptable for fixed connections.
6. (f) When attaching bonding and grounding clamps or clips, a secure and positive metal to metal contact shall be made. Such attachments shall be made before closures are opened and shall not be broken until after static generating activities are completed, and/or closures closed.
7. (g) Static bonding installations shall be so designed, constructed, installed and maintained to prevent static charges of different potential from arcing from one conductive object to another.

Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.

History

1. Amendment to subsection (g) filed 12-11-68; effective thirtieth day thereafter. Approved by State Building Standards Commission. (Register 68, No. 47).

2. Amendment of section and repealer and new Note filed 9-6-94; operative 10-6-94 (Register 94, No. 36).

3. Amendment of subsection (c) filed 8-26-2008; operative 9-25-2008 (Register 2008, No. 35).