With the ubiquity of super bright LED lights it might seem strange to recommend one-time-use glowsticks. But these Cyalume Chemical Light Sticks, and their ability to function in almost any condition, have earned a spot in my emergency kit.
My obsession with alternative light sources really kicked in when I started caving with increased frequency. One of the main tenants of caving is that you never go into a cave without three sources of light. This is because subterranean activities are particularly brutal on electronics, especially lights. No matter how weatherproofed a light source may be, the dust, water, and physical strain will eventually cause it to malfunction. This explains why super simple carbide lamps and plumbers candles were the go to light source for ages underground (it didn’t hurt that they could also keep you warm, with the main downside being the occasional explosion).
While a glow stick won’t keep you warm, it will provide light in emergency situations where other lights might falter, and it’s exactly this reason that I throw one or two 12-hour glowsticks in my pack. At 6″ in length, they are not the traditional glow stick you see at concerts, but instead are significantly brighter, and depending on the model, produce longer lasting light.
As with most tools in my emergency kit, I’ve never had to use these in an emergency. But I have had the pleasure of playing around with them in other situations and I’ve been impressed. They provide ample amounts of light for navigation, and they last long enough that they’d be an asset in many scenarios, especially during a rescue. Unlike LED lights, these glowsticks provide ambient 360-degree light which is especially useful when working in larger parties where direct sources of light can unintentionally blind, or while sitting around a campsite.
While I’m not thrilled about the one-time-use nature of glow sticks, their low cost has become an asset. I keep a few in my trauma kit in my car as a means of attracting attention in an emergency (as they are a safer alternative to roadside flares), or during those times when someone I’m with needs a loaner light source that I’ll likely not see again. While their ubiquity is great, it’s important to remember that due to their reactivity they have a limited shelf life. The industrial grade Cyalume SnapLight model has a shelf life of around four years, while the military model (built to DOD specs) is slightly less. That’s not to say these won’t work after four years, but that you should expect a reduction in chemical luminescence as it ages.
Outside of being a functional source of light, I must admit that there is something special about the chemical light they produce. I find it impossible not to experience a certain amount of child-like glee when I crack one and see the light radiate out, erasing the darkness. It’s just cool.
[Here is the Cyalume SnapLight MSDS (PDF) for anyone interested, however, this may be out of date as it appears this model is phthalate free. --OH]