Glow-in-the-Dark › II: Glow-in-the-Dark Science and Education

II: The Science, Safety and Education of Glow Games



If you’ve ever wondered what makes glow-in-the-dark games glow, then you have to learn a little about the science behind it. There’s a lot of fancy science jargon and complicated chemical explanations coming up, but the short explanation is this: The “snap” we hear when cracking a glow stick comes from a glass vial being broken that allows the chemicals to mix together and produce the desired glow. 

Glow sticks contain phosphor, a substance that soaks up energy when exposed to light and then radiates that light in the dark. All phosphors have three characteristics:

  1. The type of energy they need to be energized
  2. The color of light that they radiate
  3. The length of time that they will continue to glow after being energized 

Glowing novelty products, such as bracelets and sticks, are made from different chemicals. They contain a small glass vial which contains a mixture of hydrogen peroxide and phythatic ester. Surrounding the glass vial is an additional chemical called phenyl oxalate ester. Once you crack a glow stick the glass vial is broken, allowing the phyhalic ester, hydrogen peroxide and phenyl oxalate ester to mix. When these chemicals get mixed together, it creates the luminous glow we all associate with glow sticks.


LED (light-emitting diode) lights are a little less complicated. Glow toys that are made with LED lights use electric current to produce light from energy. They’re a lot like a regular ol’ light bulb, but differ in some key ways:

  1. They last A LOT longer
  2. They don’t get hot to the touch
  3. They don’t have a filament

Instead, LEDs involve a semiconductor structure to emit one color of light and create a sort of electroluminescence.

But what is a semiconductor? A semiconductor is made of a material, usually silicon, that partially conducts an electrical current. So while a material like wood or rubber doesn’t conduct electricity at all, a material like copper or silver (or any metal) is extremely conductive. A semiconductor lives between the two extremes.

The color of light an LED creates depends on the chemical make-up of the material used. They may have a colored plastic shell that diffuses the color and makes it easier to see, or they may have a clear plastic shell and still have colorful light. Because they’re small and don’t require a lot of energy, LEDs are an efficient and safe way to make toys shine. Most LED toys are powered by a low strength battery but still give off a very bright glow.



Glow-in-the-dark material is generally not toxic. The majority of toys on the market today are made with government standards that regulate the manufacturing process and make them safe. However, you should always take precaution even though most glow-in-the-dark toys and glow sticks are labeled as “non toxic.” Be sure to look at their make-up before giving them to children. For example, when you purchase glow-in-the dark products such as paint, slime, or bubbles, look at the ingredients, follow the directions and use proper precautions. Adult supervision is always imperative when using any kind of chemicals.

While chemicals used to make glow sticks and glow bracelets are safer than most household cleaners you have on hand, they still require precautions. Toys made with phosphors such as glow-in-the-dark balls and frisbees are safe for long-term handling as long they are not ingested or inhaled. Because of the process that toy manufacturers use when activating the phosphors to create extended luminosity, you should take care not to ever let a child chew on these or put them in their mouth. An intact glow stick or bracelet is a safe and fun object as long as it’s being used properly. Don’t ever try to cut or puncture a glow stick. This will keep you from the risk of broken glass inside the glow stick as well as any chemical exposure. 


While all glow toys are generally safe, LED-lit toys offer the lowest risk because the lights themselves do not contain any dangerous chemicals. LED-lit toys are typically very durable and resistant to breakage making them very safe. LED bulbs do not emit a bright enough light to damage eyes and the bulbs do not get hot enough to be harmful. In addition, the LED light parts in the toys are usually hard for a child to access while operating as they are typically screwed in. Plus, it is safe for parents to handle LED lights to replace batteries if needed. The only hazard LED lights pose is if they are broken as they could possibly become a choking hazard. 

The safety of LED lights extends to LED powered pool toys. The batteries are generally at such a low voltage that you cannot be electrocuted. The worst thing that will happen should water get into the batteries is that the light will turn off.

If you do suspect a battery or material has been ingested, you can get free, accurate and confidential Poison Control answers online or by calling 1 (800) 222-1222.


Playing glow-in-the-dark games in the dark is awesome and the ideal way to play these games. But how do you ensure that everyone is safe?

Use these steps to make your next glow-in-the-dark adventure safe:

  1. Insure the playing field is completely clear of obstructions or other tripping hazards.
  2. Have glow-in-the-dark markers set throughout the playing field
  3. Always have an adult present
  4. Don’t be afraid to shine some light into the playing field. You’ll still see the glow.


Glow games are ready made for science explorations and schoolyard fun. The science of glow sticks, batteries and LED lights are all great tools for education. For younger groups, such as Pre-K, try bringing in glow sticks, and having them crack and shake the sticks for fun bracelets. This can lead to a hide and seek game indoors or outdoors or a glow bracelet dance off. You can even begin explaining the science: There are two chemicals in the glow sticks, and when one meets the other, they create a reaction that emits the glow. Using this language sets them up for future science classes while still keeping them entertained. 

With older kids, you can really have some fun. Try cutting open the glow sticks and pouring the liquid into bubbles as a way of talking about the chemicals with a big payoff. Bringing in the basic ingredients of a glow item, such as glowing slime, can be a fun activity to make in the classroom and describe the chemical reactions happening in real time. 

Even older, you’re ready to get electrical. Young teens and adults can make their own batteries to create LED items for glow games. You can give an introduction to the history of the lightbulb and batteries (see our previous post) and then send them off to add their own historic invention.

Share this: