What Is the Safety Triangle?

25 October 2016

In 1969, Frank E. Bird Jr. committed to a study of industrial accidents based on the previous research of H.W. Heinrich, which established the ratio of 1 major injury to 29 minor injuries to 300 no-injury accidents.

Since Heinrich estimated the relationship and because his sample was not randomly chosen, Bird wanted to determine what the actual reporting relationship of accidents was by the entire average population of workers.

SEE ALSO: 6 Strategies to Improve Your Company's Safety Program

Importance Of Bird's Study
What is the Safety Triangle?

Bird analyzed 1,752,498 accidents reported by 297 cooperating companies representing 21 different industrial groups employing over 1,750,000 workers who served over 3 billion hours during the study.


The study uncovered the following ratios in accidents reported: For every reported major injury (resulting in fatality, disability, lost time or medical treatment) there were 9.8 reported minor injuries (requiring first-aid), 30.2 property damage accidents, and 600 incidents.

It must be remembered that these ratios represent accidents reported and incidents discussed – not what actually occurred. This study was not intended to predict the ratio of injuries for any particular occupational group or organization.

Putting The Safety Triangle To Work 

What this study has declared is that major injuries are sporadic so we should take action on the more recurrent and less compromising events to decrease the chance of total accident losses from transpiring.

SEE ALSO: Properly Document Safety Issues to Create a More Secure Work Environment

In 2003, ConocoPhilips Marine conducted a similar study that revealed a significant difference in the ratio of serious accidents and near misses; for every single fatality there are at least 300,000 at-risk behaviors (activities that are not consistent with safety protocol). Illustrated by this ratio, effective safeguarding and training will shrink at-risk behaviors, which ultimately reduces the chance of a fatality occurring.

Learn more by downloading a free Safety Ebook to simplify and improve your team's safety training while increasing performance. 

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About The Author

Heather Dueitt is the Director of Marketing and Communications for NoteVault. She brings more than 15 years of experience to the team including teaching at New York University and is a regular contributor for Forbes. Prior to moving to San Diego, she worked with top-tier global brands including Samsung and Dove and her campaigns were awarded over a dozen industry accolades. Heather comes from a family of civil engineers, architects and contractors and has grown up around the AEC industry.