16VAC25-70-30. Preparation.
Entry into a confined space shall not be made unless the qualified person has assured that the following procedures have first been completed.
A. All pumps or lines which may convey flammable, injurious, or incapacitating substances into a space shall be disconnected, blinded, double blocked and bled, or effectively isolated by other means to prevent the development of dangerous levels of air contamination or oxygen deficiency within the space. The closing of valves alone, or the closing of valves and locking or tagging them, is not considered effective protection. The disconnection or blind shall be so located or done in such a manner that inadvertent reconnection of the line or removal of the blind are effectively prevented.
B. All fixed mechanical devices and equipment that are capable of causing injury shall be placed at zero mechanical state (ZMS). Electrical equipment, excluding lighting, shall be locked out in the open (off) position with a key-type padlock except in cases where locking is impossible; in such cases equipment shall be properly tagged in accordance with 16VAC25-90-1910.145(f). The key shall remain with the person working inside the confined space.
C. All confined spaces shall be emptied, flushed, or otherwise purged of flammable, injurious, or incapacitating substances to the extent feasible. Initial cleaning shall be done from outside the confined space to the extent feasible.
D. Where the existence of a hazardous atmosphere is demonstrated by tests performed by the qualified person, the confined space shall be mechanically ventilated until the concentration of the hazardous substances is reduced to a safe level, and ventilation shall be continued as long as the recurrence of the hazards is possible or appropriate personal protective equipment, as defined in Subpart I of the Virginia Standards for General Industry (16VAC25-90-1910) and Subpart E of the Virginia Standards for Construction Industry (16VAC25-175-1926), shall be used by all employees during entry. The mechanical ventilation shall be located in an unconfined space with the blower intake away from traffic and sources of exhaust fumes and the blower exhaust away from the confined space opening. The blower shall be located a minimum of five feet from the confined space opening to avoid returning purged air into the confined space.
E. When the confined space entry occurs on a public thoroughfare, warning devices, barricades, and traffic cones shall be used for the protection of workers and shall conform to the American National Standards Institute D6.1-1978, "Manual on Uniform Traffic Control Devices for Streets and Highways."
Statutory Authority
§ 40.1-22(5) of the Code of Virginia.
Historical Notes
Derived from VR425-02-30, § 3, eff. November 15, 1987; amended, eff. July 1, 1988.