It's a slight skin irritant and the tubes contain bits of glass that could be hazardous. A poison control center website says that if it gets in the eyes they should be rinsed for 10 minutes. It isn't "drop dead" toxic but it's probably not something that should be played with outside the glowstick.

Keep in mind that this stuff had just been microwaved, which they specifically tell you not to do, so this shit was also most likely quite hot.