By: K. Lee Stone


Lee Stone has a Master's degree in toxicology from Indiana University and is a certified Chemical Hygiene Officer. Lee has served as the Laboratory Safety Manager for the Office of Environmental Health and Safety since 2004.


E-mail Lee Stone at: leestone@iupui.edu



Is 1 the Lonliest Number?

The number "1" can mean many different things. If youa re taking a survey, for example, you must read the instructions very closely because depending on the survey the number 1 can mean excellent or it can meant very poor. The same is true when comparing the National Fire Protection Agency (NFPA) ratings or the Hazardous Materials Identification System (HMIS) with the new The Globally Harmonized System (GHS) of Classification and Labelling of Chemicals


The number "1" in the health section of the health section of the NFPA diamond or the HMIS rectangle would indicate that the chemical can cause irritation. A number "1" placed in the flammable section would indicate that the chemical could ignite after being heated. This same number placed in the reactivity section would inform you that the chemical is typically stable. The number "4" in any of these quandrants would indicate the highest level of risk.


Th inverse is true in the new GHS labeling system. The number 1 means "Danger" or the highesl level of risk. This conflicting meaning of the number one can potentially create confusion.


Please make sure you read the Safety Data Sheets (SDSs) very carefully and look for the descriptions that accompany the hazard classifications so understand the meaning of the numbers.



Lab Notes is a quarterly publication by the IUPUI Office of Environmental Health and Safety. Lab Notes is designed, edited and published by K. Lee Stone.

"Don't Learn Laboratory Safety by Accident!"