Research report on printing press danger zones

Research paper
Lockout and Guarding
Forest Products

IRSST Report: Validation of a Mechanical Hazard Fault Tree for Interventions in Printing Press Danger Zones


In 2006, a survey of the safest common practices relating to interventions on printing presses, including several danger zones. 

From this survey, a fault tree was developed to trace the combinations of causes leading to crushing of a body part of a worker in a printing press nip point. This study focuses on the crushing risks related to these machines' nip points.

The IRSST research team validated the logic and thoroughness of the fault tree with a methodology for risk assessment and safe procedures relating to the execution of the four following operations:

  • Roller and blanket cleaning and washing,

  • Plate insertion and removal,

  • Blanket insertion and removal,

  • Paper threading.

Application of this methodology led to the result of the study, namely a final fault tree with 300 combined causes, occupying 10 levels, and that can explain the crushing of a body part of a worker by one or more printing press rollers/cylinders during an operation.

This fault tree makes it possible to visualize the causes and consequently to find solutions in order to avoid this crushing during an operation. While this fault tree is not directly transposable to other machines with nip points and for which the causes of crushing in a nip point should be studied, it remains a very good starting model and could be adapted with a minimum of effort.

The Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST), established in Québec since 1980, a scientific research organization well-known for the quality of its work and the expertise of its personnel.