When I started work on this column, I looked around my house for warning symbols on household chemicals. To my surprise, I found very few. This has to do with where the product is sold and whether it’s intended for normal consumers or industrial use.

A chemical product that is sold in a department store is intended for household use, so no warning symbols are required. If the same product is sold to industry, different labelling regulations apply.

Occasionally, a product is sold to both groups using one label. In that case, the manufacturer has to meet the industrial labeling regulations and the consumer products labelling regulations. An example of this that I found in my home is the lubricant WD-40. The label meets all the industrial requirements, but also looks nice as a consumer label.

Many years ago, I launched a consumer medical product in Canada and in the U.S.A. I had a crash course in package design. The product ended up with two completely different types of package, to suit two types of pharmacy displays, so I ended up with two separate products and a lot of added cost. There are advantages of having one label for two markets.

Industrial labels don’t have to appeal to consumers. They aren’t intended to sell the product; you’ll see products like this in auto parts stores. The label of a consumer product is a big part of what gets the consumer to put your product into their shopping cart instead of the competitor’s brand. Think of toothpaste labels like “new and improved” or “whiter, brighter.” Toothpaste doesn’t need any warning symbol, but you get the idea. I spend more time reading toothpaste labels to decide the best one, than I do on just about any other grocery product that I buy.

When companies market a chemical, they walk a line between enticing us to buy their product and at the same time, warning us about its potential hazards.

Recently, someone at work told me they didn’t want to use our hand sanitizer because I labelled it “extremely flammable.” I explained that all hand sanitizers are extremely flammable because they contain high concentrations of alcohol. In the safety biz, we use “signal words” on product labels, such as “warning” or “danger” to emphasize the hazard.

In Canada, health and safety regulations require chemicals to be labelled in a certain way, known as the Workplace Hazard Materials Information System. The U.S.A. uses a similar format called the Hazard Communication Standard. Now all countries have aligned warning symbols into an international standard called the Global Harmonized System. When shippers are moving a product, a different set of labelling rules apply, the Transportation of Dangerous Goods Act. This tells a fire department how to deal with a chemical spill or tells a ship’s crew where to put the chemical container on their ship. You’ll see TDG signage on fuel trucks.

Recently, a co-worker told me about his cat eating some artist’s paint, which caused concerns about the paint’s toxicity. I wonder if the cat’s name is Vincent. (Van Gogh, at a low point, once ate his own paint). Editor’s Note: The cat’s name is Cash, and he’s a very good boy.

In this case, the paint was non-toxic, which my co-worker learned by Googling its label and discovering the non-standard warning symbol “AP.” That symbol (unintuitively meaning nontoxic) comes from the Art and Creative Materials Institute, which rates the toxicology of art products. This non-standard approach to warning symbols is an example of unclear warning labels, and why having clear, instinctively recognizable warning symbology is important.

Two symbols that most people recognize are the radiation symbol and the pirate symbol.

The ionizing radiation symbol is called the Trefoil. It’s a black dot surrounded by three pie shaped wedges. It’s illegal to post a sign with this symbol in Canada, unless there is a true risk of radioactive contamination. You’ll see this symbol at home on the back of smoke detectors. (They’re completely safe as long as you don’t tamper with it). The only other place you’re likely to come across this symbol is on an x-ray. X-rays aren’t radioactive, but the hazard is similar.

Probably the most well-known warning symbol is the skull and crossed bones. Its use as a warning symbol dates back much earlier than as a pirate’s flag. It may have begun in 12th century, with the Knights Templar, who placed a skull between crossed femurs as part of one of their rituals. It has a strong cultural reference and because of that, it is still used today as the chemical warning symbol to show “acute toxicity” (poison).

Consumer products may have other symbols, for other purposes. Some are related to quality standards, such as ISO. These also have subsets such as environmental, organic, recyclability, etc. There are also marketing symbols, such as “approved by the American Dental Association,” which basically means the manufacturer paid a fee to that association to use its logo.

Highways are where most symbology appears today. I learned something interesting about road sign symbols years ago, in an engineering psychology course. We discussed road sign design failures. Designers discovered that negative road signs, such as an arrow with a red stripe through it (a negative message meaning “don’t go this way”) were ineffective.

Instead, the road designers found that a sign with an arrow with a green circle around it (a positive message meaning “go this way”) worked much better. The road designers figured out that when our brains see a negative symbol, it has to do two processes: what not to do and what you need to do instead.

Therefore, it’s much faster and clearer for drivers to get a single, positive message: “go this way.” This is why most newer road signage uses positive symbols.

It’s helpful to be aware of the warning symbols you’ll see around the home, and their meanings.

  • Danger Flammable: Found on containers with petroleum (things that burn well like lubricants and paint thinner), it’s even molded into those red plastic gasoline jugs.
  • Extreme Danger or Extremely Flammable: Appears on things that are an even greater burning danger, such as paints and aerosol containers with petroleum products.
  • Caution Irritant: Appears on insecticides, lawn chemicals, and cleaners. These are eye hazards (things that spray or splash) and can burn or irritate your skin.
  • Harmful if Swallowed: This is your warning for children (and cats). Examples are diluted household cleaners that are widely used by everyone. It may also say “fatal if swallowed.” In either case, those words matter—seek emergency medical care at once.
  • Use in a Well-Ventilated Area: This warning is probably about the hazard of chemical pneumonia, caused by inhaling mists or vapours from bleach or pesticides or dust from fertilizer. Learn more in this recent Halifax Magazine column.
  • First-Aid Information: This indicates your product has serious dangers and the manufacturer knows it.
  • Usage Instructions: On concentrated chemicals (such as bleach, calcium-lime-rust descaler, or other strong acids), these provide another indicator you’re dealing with a serious product that you must use correctly. Don’t combine such products.

Always read the label, follow instructions, and wear safety glasses when using chemicals, and you should be fine.

Halifax Magazine