Supplied-Air Respirators

Tritium Primer

DOE-HDBK-1079-94

RADIOLOGICAL CONTROL

Flexible ducts can provide adequate ventilation during maintenance in a glovebox with

a panel removed. In this application, a flexible duct can be connected to a gloveport

before the panel is removed, and then the work can proceed safely.

Supplied-Air Respirators

In general, only supplied-air respirators are effective in preventing inhalation of airborne

tritium. Two types of air-supplied respirators are available: self-contained breathing

apparatus (SCBA) and full-face supplied air masks.

An SCBA, consisting of a full-face mask fed by a bottle of compressed air carried on the

worker's back, provides excellent protection against HTO inhalation. Because the mask

provides no protection against absorption by most of the skin, the SCBA is normally

reserved for emergency use only. The protection factor of 3 or more afforded by the

SCBA may be adequate for some applications. An SCBA can be used as an added

precaution during certain maintenance or operations that experience has shown should

not result in the release of significant amounts of HTO. Nevertheless, the potential for

exposure is real, and the SCBA gives the worker time to leave the area if necessary

before a skin exposure occurs.

Full-face supplied-air masks are also available. Because the air is normally supplied by

a fixed-breathing-air system, they are not practical for many emergency situations and,

consequently, are not as popular as SCBAs.

Supplied-Air Suits

Because of the inherent disadvantages associated with respirators and other breathing

apparatus, supplied-air plastic suits that completely enclose the body are often used by

facilities that handle large quantities of tritium. Although they afford reasonably

complete body protection, they are slow to don and cumbersome to wear. For these

reasons, they are not favored for rescue work where time and mobility are important

considerations. For certain maintenance operations outside of glove boxes with a high

degree of risk, supplied-air suits may be quite useful.

For tritium work, supplied-air suits are constructed of materials that have acceptable

permeation protection against HTO and provide good tear and abrasion resistance.

Because of the closed environment, and the additional background noise caused by the

flow of air into the suits, communication between personnel may require special

equipment or methods.

Protection from Surface Contamination

Experience at tritium laboratories has shown that many tritium exposures to personnel occur as

a result of contact with highly contaminated surfaces. Sudden and significant releases of

airborne tritium occur mostly as the less toxic form HT and are quickly detected by portable or

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Tritium