Okla. Stat. tit. 17, § 17-54: Definitions

As used in this act:

1. "Frac tank" means any portable or stationary, high volume

holding vessel designed and constructed for use in separating,

storing or temporarily holding materials used in or resulting from

fracturing techniques in oil and gas exploration;

2. "Fracturing" means any processes, chemicals or other

materials used to enhance an oil and gas well recovery operation;

3. "Manway" means any opening on a frac tank allowing a person

ingress into or egress from the interior of the vessel; and

4. "Unprotected" means a manway without grates, bars or other

means of halting unexpected ingress into or egress from the interior

of the vessel.