Definitions.

As used in this subpart— Action level means an airborne concentration of benzene of 0.5 parts of benzene per million parts of air calculated as an eight hour time-weighted average, generated from vessels regulated by this subpart. Authorized person means a person specifically authorized by the person in charge of the vessel to enter a regulated area. Benzene means liquefied or gaseous benzene (C 6 H 6 ; Chemical Abstracts Service Registry No. 71-43-2) and includes benzene contained in liquid mixtures and the benzene vapors released by these mixtures. The term does not include trace amounts of unreacted benzene contained in solid materials. Breathing zone means the area within one foot of a person's mouth and nose. Employee means an individual who is on board a vessel by reason of that individual's employment and who is employed directly by the owner, charterer, managing operator, or agent of that vessel. Employer means the owner, charterer, managing operator, or agent of a vessel. Emergency means an occurrence, such as an equipment failure, a container rupture, or a control equipment failure, which results or may result in an unexpected release of benzene. Operations involving benzene means any operation that could subject a worker to benzene exposures above the PEL, including cargo transfer operations involving connecting or disconnecting liquid or vapor hoses; cargo tank gauging and sampling; and cargo tank gas freeing, venting, and cleaning. Performance standard means the standard in § 197.520. Person in charge means— (1) For a self propelled vessel, the master or licensed operator of the vessel; and (2) For an unmanned barge, (i) The licensed operator of the vessel for barge tows; (ii) Where there is no licensed operator, the tankerman who signs the declaration of inspection for a cargo transfer for an operation involving benzene; or (iii) Where there is no licensed operator or tankerman, the individual in charge of the vessel when it is moored at a fleet, terminal, or other place. Permissible exposure limits or PELs mean the exposure limits specified in § 197.515. Personal exposure means the concentration of airborne benzene to which a person would be exposed if that person were not using a properly fitted respirator in compliance with § 197.550 and the personal protective clothing and equipment in compliance with § 197.555. Regulated area means an area designated in compliance with § 197.535. Short-term exposure limit or STEL means an airborne concentration of five parts of benzene per million parts of air (five ppm), as averaged over any 15 minute period. Time-weighted average exposure limit or TWA means an airborne concentration of one part of benzene per million parts of air (one ppm), as averaged over an eight-hour period. This eight hour period covers the time, up to eight hours, that the employee works in any 24 hour period. If the exposure period is less than eight hours within the 24 hour period, the difference between eight hours and the time of exposure (that is, the unexposed time) is averaged into the TWA. If the exposure period exceeds eight hours in any 24 hour period, sum the products of each exposure level multiplied by the time at that exposure level. The TWA is the value of that sum divided by eight hours. Vapor control or recovery system means a system of piping and equipment used to collect vapors by transporting the vapors from a tank being loaded to a tank being unloaded or by collecting the vapors and containing them, recovering them, dispersing them in a location remote from personnel, or destroying them.