Pennsylvania Code
Title 34 - LABOR AND INDUSTRY
Part I - Department of Labor and Industry
Chapter 5 - BLASTING, DEMOLITION, FIREWORKS AND EXPLOSIVES
Subchapter D - EXPLOSIVES
GENERAL PRECAUTIONS: EXPLOSIVE VAPORS
Section 5.94 - Ventilation

(a) Where the amount of gases or vapors produced is deemed by the Department or its authorized representative to be a menace to the safety or health of employes, an efficient exhaust system, the plans of which shall be approved by the Department, shall be installed in the rooms designated and kept operating at all times when persons are employed therein.

(b) During necessary repairs which might cause a spark, other operations shall cease, and the repairs shall be made only after adequate ventilation has been established to free the room or portion of the plant from explosive gas or vapor.