What makes a glowstick glow? Is it bad for the environment? What's better for the environment: a glow stick or a flashlight?
Halloween is one of the most fun days of the year for kids - dressing up and running around getting free candy in a sugar-induced surge of excitement. As parents, we want to keep our children safe, and glow sticks are a handy and relatively child-proof way of keeping an eye on little ones.
But is a glow stick the best option for lighting up the night?
How do Glow Sticks Work?
The glow in a "crack and shake" glowstick is caused by a chemical reaction. Usually the chemicals involved are hydrogen peroxide and phenyl oxalate ester. The hydrogen peroxide is usually contained in a glass container that floats inside. When you bend the glowstick, it breaks the glass container, and the chemicals mix and begin to react (glow). As the mixture glows, it produces a chemical by-product called phenol.
According to our handy copy of the Merck Index (11th Edition), phenol has the following human toxicity:
Ingestion of even small amounts may cause nausea, vomiting, circulatory collapse, tachypnea, paralysis, convulsions, coma, greenish or smoky-colored urine, necrosis of mouth and G.I. tract, icterus, death from respiratory failure, sometimes from cardiac arrest. Average fatal dose is 15g but death from as little as one gram has been reported.
Now.. this may sound worrisome, but remember that the amount of phenol in a glow stick is very small. In fact, some people actually break them open on purpose and rub them on their skin, and we aren't hearing about mass glowstick poisonings in the news. And keep in mind that some common household cleaners contain phenol, so it may already be present in your home.
Glow Sticks and the Environment
Although the amount of chemicals in each individual glow stick is very small, as a general society, we tend to see a lot of them every Halloween. Because the glow sticks contain chemicals, the plastic shell cannot currently be recycled. This means that the millions of glow sticks used every year in North America are simply dumped in your local landfill (or in Toronto's case - Michigan's landfill).
Lawson Oates, director of the City of Toronto's environment office, commented last March that a glow stick is "derived from petro-chemicals and is energy-intensive to make". In addition, they are "just adding to the vast pile of waste the city must contend with every day".
It would be handy if there were research that investigated the size of the footprint of glow sticks on the environment. But the following questions remain unanswered:
- How much fossil fuel and energy does it take to create the plastic shell of a glow stick?
- How long does it take for the plastic shell to degrade?
- What happens to the chemicals if/when the plastic degrades?
- Can the chemicals inside make it into our water supply?
If one of our readers is aware of research that addresses these questions, please comment on this article and point it out. In the meantime, this remains food for thought.
An Alternative to Glow Sticks
Another way you can light up the children this Halloween is by using a coloured flashlight. Simply take a small flashlight, and tape a piece of tissue paper over the light. Voila - now your little ghouls have colourful light to help keep them safe, and with rechargeable batteries, it's almost waste-free!
References & Resources
- Light Sticks - Chemical & Engineering News
- How Light Sticks Work - How Stuff Works
- What Makes Light Sticks Glow? - The Chemical Engineers' Resource Page
- Glow stick - Wikipedia
Image by Gary Simmons