Toothpaste color marks debunked as manufacturing technicalities

Social media rumors claiming that the colored rectangular marks on the bottom of toothpaste tubes indicate ingredient safety are false. Common misinformation suggests that green marks signify natural ingredients, while red or black marks indicate high chemical content or toxicity.

According to experts from the American Dental Association (ADA), these marks are actually technical “eye marks” used in automated manufacturing. Dr. Richard Macey of the University of Manchester explains that optical sensors on packaging machines scan these marks to identify the correct stopping point for cutting and heat-sealing the plastic tubes. The color of the mark is chosen solely for high contrast against the tube to ensure machine accuracy and has no connection to the product's medical or chemical composition.

Health professionals warn that following these rumors can lead to dental risks, as consumers may discard safe products or switch to unverified, homemade, or unregulated alternatives in an attempt to find “natural” options.