To a child, everything in the house looks like a play toy. While this is great for parents looking to entertain and distract their child with the hundreds of baby toys they got at the baby shower, it also poses a huge risk for curious babies that find their way to the cleaning cabinet. Before a toddler knows what’s poisonous and what’s not, there needs to be a way to warn them easily. For decades, the skull and crossbones were used to warn children. However, at a certain point, people realized that the symbol became too popular as the Jolly Roger, and sports symbols, so children no longer took it as a warning. That’s when Mr. Yuk was designed.

Mr. Yuk is a shade of yellow-green that, when tested on a focus group of children, was called “yucky.” For that reason, experts decided it would be the perfect way to deter children from poisonous chemicals and materials. However, research on a child’s perception of color shows that you should not necessarily rely on Mr. Yuk to teach your children which materials in your home are poisonous. Until your baby is old enough to understand what “no” really means, you should keep all hazardous chemicals locked away to prevent ingestion. Studies show that children can’t discern colors until they are approximately two years old. Even then, there’s no telling what their preferences might be. While we might see yellow-green as a “gross” color, a child might not think anything of it and feel it’s no different than purple or blue. The only color preference that researchers have found in babies is an attraction to red because it is one of the first colors the human eye can discern. Even so, an attraction doesn’t necessarily indicate a preference.

Don’t assume that sticking a Mr. Yuk sticker on a dangerous chemical or product in your home is enough. The design was intended to deter children from certain items but the color alone might not be enough. You’ll need to make sure your child does not have access to these products by using safety locks and specific placement, and eventually that he understands fully which to avoid. Mr. Yuk might be useful once your child understands it’s meaning. Until then, you need to monitor your baby very closely if you have dangerous chemicals anywhere in your home because everything is food to a toddler.

Source: Dominique Bremond-Gignac et al: Visual Development in Infants: Physiological and Pathological Mechanisms. Current Opinion in Ophthalmology Volume 22 Issue 1 pp. S1-S8 April 2011