Ever heard of Rachel Carson's Silent Spring? Thanks to her pioneering work in this 1962 book, chemical manufacturers are legally required to fully disclose the potential health risks of the products on "Right to know" labels.
These labels play a crucial role in community and workplace safety by telling people the side effects of chemicals they might be exposed to during their workday. The Occupational Safety and Health Administration ensures that this happens by requiring that information about the hazards of all chemicals that are produced or imported are made known to employers and employees. One of the main ways that people learn about these health risks is through labels, which are regulated by OSHA.
This labeling system, known as NFPA 704, was created by the National Fire Protection Association to alert emergency responders to the presence of hazardous materials. These labels typically display the information in a diamond with four differently-colored quadrants. It identifies what kind of hazard the chemical poses, and specifies the degree of severity through a rating system of zero (minimal hazard) to four (severe hazard).
Hazards are assigned to one of four categories, which are displayed on the diamond-shaped sign as follows, starting from the left and working around clockwise: "health" is on the left, "flammability" is at the top, "instability" is on the right, and "special hazards" is on the bottom. These quadrants are also color-coded for easy visibility: blue for health, red for flammability, yellow for instability and white for special hazards.
The special hazards section is the only one that doesn't use the numerical rating system. Instead, the severity of special hazards is indicated by either a "W," which means the chemical has an unusual level of reactivity with water (and firefighters or other first responders should use caution), or "OX," which means the material is an oxidizer, which are substances that are either combustible themselves, or may cause or contribute to combustion of other materials.
"Right to know" labels should be posted on at least two exterior walls, though ideally they should be posted near each principal means of access to the area with hazardous materials.
These labels are regulated by the United Nations' Globally Harmonized System of Classification and Labeling of Chemicals (GHS). The GHS system was first created by the United Nations in 1992 when labor, business and government leaders decided to establish international standards for labeling hazardous materials. GHS pictograms are made to depict the hazard in a way that can be understood globally, by people who speak any number of different languages.
To meet GHS regulations, manufacturers must put these labels on any product that presents a potential hazard. Labels are typically rectangular, and need to include six different pieces of information. First, at the top of the label, there needs to be a "product identifier" that states the name of the chemical. Second, GHS-approved symbols must be used to indicate the level of risk. Approved images include a skull and crossbones (toxic), a flame (flammable) and a exclamation mark (irritant).
Most of the images appear on a white background in black with a red, diamond-shaped border. Labels are also required to include a "signal word" followed by a hazard statement. Typical signal words are "Danger" or "Warning." The hazard statement should explain the physical, health or environmental hazard that the chemical may cause. Examples include "May be harmful if swallowed" and "Causes severe burns."
Finally, a precautionary statement and the contact information for the supplier must appear at the bottom of the label. The precautionary statement should provide information about what actions should be taken if someone comes into contact with the chemical. Possible precautionary statements include "If swallowed, call poison control" and "If in eyes, rinse with water." Supplier information should include the company's name, address and phone number.