“I’ve had kids for 15 years now, giving me plenty of time to reflect on what it means to tell someone to ‘be careful,’” says Tim Barton, chief safety officer at the University of Tennessee Health Science Center. “My conclusion is that this phrase is almost too ambiguous to be meaningful.”

To some, being careful means practicing vigilance while running with scissors. To others, it means not running with scissors at all. These differing perspectives persist into adulthood, too.

Cynthia White, environmental health and safety manager at Rochester Institute of Technology, learned this lesson firsthand when she brought her coffee cup into a lab that tested film emulsions many years ago. “I always kept it by the PC, away from samples and other hazards,” she relates. “I thought I was being very careful so it wouldn't be an issue. One day, as I got to the bottom of my cup of coffee, there was a layer of emulsion in the bottom of the cup. I never brought a drink in the lab again.”

“I’m careful” thinking can easily affect many everyday practices in the lab:

  • Pouring carefully instead of wearing appropriate gloves
  • Holding one’s breath until the bottle is closed instead of working inside the fume hood or biosafety cabinet
  • Handling reactive materials with a “steady hand” rather than using engineering controls and protective equipment

When confidence in one’s personal sense of cautiousness causes a person to ignore basic rules of safety, what is being practiced is the opposite of caution. Worse, “I’m careful” thinking can rot the roots of organizational safety culture, says Barton, who also serves as president of the Laboratory Safety Institute’s board of directors. He suggests that in most situations, it is better to advise others to “be careful by . . .”

For example, he suggests advising others to “be careful by wearing chemical splash goggles” or to “be careful by checking the SDS for hazards.” Such guidance builds a culture of accountability and mindfulness where safety is practiced through concrete actions instead of what “feels safe.”

In the well-known hierarchy of controls, the notion of “being careful” is notably absent. Instead, this safety framework promoted by the American Chemical Society trains us to mitigate hazards by elimination, substitution, engineering controls, administrative controls and PPE — concrete, specific strategies and equipment.

Barton offers a tragic story from his personal life to drive the point home: “A guy I went to high school went on to become a lawyer in New York City. One night he had locked himself out of his apartment. Apparently he knew he had an unlocked window. Rather than call a locksmith, he decided to exit the hallway window and make his way along a ledge to the window of his apartment. I’m sure he was being careful, but all that care wasn’t enough to stop him from falling to his death. He was about 30 years old.”

There is no doubt that being careful is important, but it is more important to take specific, planned steps to protect yourself and others in case “being careful” isn’t enough.