Signal words on pesticide labels are based on both the active and inert ingredients in the product.

• A. True
• B. False
• C. Sometimes
• D. Not sure

Answer: (A)

The warning level on a pesticide label is based on the hazards of the finished product, not just the active ingredient. Inert ingredients—solvents, carriers, surfactants, and other formulation components—can affect how toxic the product is in real use. They can influence dermal absorption, inhalation exposure, and irritation potential, which together shape whether the product’s acute toxicity meets the criteria for a higher or lower signal word (such as Danger, Warning, or Caution). Since the label must reflect the hazard of the whole formulation, both the active ingredient and the inert ingredients contribute to the chosen signal word. For example, even if the active ingredient is only moderately toxic, an inert solvent that increases skin absorption or causes irritation can raise the overall hazard of the product and thus its signal word.