“You keep using that word.  I do not think it means what you think it means.”  – Mandy Patinkin as Inigo Montoya, in The Princess Bride

I find the phrase “While we never anticipate a loss of cabin pressure…” incredibly annoying.  To anticipate means to think of something that will or might happen in the future.  If the aircraft manufacturer has gone to all the trouble of installing air masks for every passenger, and the flight attendants go to all the trouble of talking about it before every flight, then clearly someone has anticipated a loss of cabin pressure. It is conceivable.

Let me assume for a moment that you are one of the dozen people in the world who is unfamiliar with the motion picture, The Princess Bride.  In this movie, one of the characters is Vizzini, an evil genius (sort of) played by Wallace Shawn, who is frequently confronted with inconvenient facts which his diabolical plans did not adequately address or anticipate.  His response is to cry out, “Inconceivable!”


A thing that is inconceivable is unimaginable.  We don’t even know what those things are because once we know what they are, even hypothetically, they’ve been imagined, conceived.  An airplane crashing into a facility is incredibly unlikely, but not inconceivable.  It has happened. It is conceivable, however unlikely.

“Unrecognized” is a much lower bar to meet than “inconceivable”.  A recognized hazard must be reasonably foreseeable.  That is, there must be a basis, not only to notice that a hazard exists and anticipate that it might lead to harm, but also to expect that it could lead to harm at some point in the near future. A hazard may not be inconceivable, but that does not necessarily mean that it is a recognized hazard.

Recognized Hazards

A recognized hazard is any hazard you are or should be aware of.  The idea of a “recognized hazard” is important because the general duty clause of the Occupational Safety and Health Act of 1970 states that “Each employer shall furnish to each of his employees employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees.”  Setting the obvious sexism of the 1970’s language aside, the general duty clause makes it a crime for any employer (male or female) to have a workplace where someone dies or is seriously hurt from a recognized hazard.

So, what does OSHA consider a recognized hazard?

  • First, does the employer’s industry recognize the hazard? An industry standard or recommended practice to address a particular hazard is very strong evidence that the hazard is recognized.
  • Second, is there evidence that the employer recognizes the hazard, regardless of the industry’s position on the hazard? Previous incidents are very strong evidence that the hazard is recognized.
  • Third, would a reasonable person recognize the hazard, regardless of the industry’s position on the hazard or the employer’s acknowledgment of the hazard.

The most commonly cited basis for recognizing a hazard is an industry standard or recommended practice. While a standard or recommended practice from one industry is typically not sufficient to establish that something is a recognized hazard in another industry, there is no excuse for any employer to be unaware of the hazards in their own industry.

Willful Ignorance

When it comes to hazards, it should be obvious that for an employer to plug his ears while repeating “nah-nah-nah-nah-nah” is not acceptable.  To act as though remaining ignorant of hazards is absolution of responsibility for those hazards is misguided. To say, “Don’t tell me, I don’t want to know, because if I know, then I have to do something about it,” is not okay.

It is important to be aware of the hazards in the workplace.  A hazard may be conceivable but not a recognized hazard. For example, airplane crashes into the workplace. However, that distinction can only be made upon awareness of the hazard. There is no requirement to address hazards that are not reasonably foreseeable.  If the hazard has not even been considered, however, it is hard to make the case that an effort to foresee the harm that may result has been reasonable.  It is especially important to consider those hazards that others in the industry have already identified as reasonably foreseeable by virtue of writing a standard that addresses the hazard.

Be Aware

Not all hazards are conceivable. Some hazards only become conceivable upon the first incident. Once that incident occurs, however, the hazard is certainly conceivable. Some hazards are already conceivable but are considered so unlikely that they are not recognized hazards. The transition from “conceivable” to “recognized” requires more evidence, either in the form of more incidents or in the form of more analysis. When the hazard is recognized, there becomes a duty to use feasible methods to correct the hazard.

That duty begins with the duty to be aware of recognized hazards.  This starts with common sense and your own experience.  Avoid the temptation to write off an incident as a fluke.

It also means knowing the standards that apply to your industry and being aware of their recommendations or of substitute measures that are equally effective.  Conferences, journals, and trade publications are essential to being aware of the hazards that have been and are being recognized.

Don’t be Vizzini.  When presented with inconvenient facts which your plans did not adequately address or anticipate, don’t cry out, “Inconceivable!” Instead, acknowledge the hazard and respond.  It is much easier to address a hazard before it results in harm than after.


This blog is based on an earlier version, “Inconceivable: Unrecognized Hazards”, posted on 23-May-2017 by Elsevier in Chemicals & Materials Now!


  • Mike Schmidt

    With a career in the CPI that began in 1977 with Union Carbide, Mike was profoundly impacted by the 1984 tragedy in Bhopal and has been working on process safety ever since.