Encourage your children to spend their free time creating chemistry projects in your kitchen. They will have a great time while they learn the fundamentals of chemistry. Put safety glasses on your children, but think twice before you let them use glasses from the kitchen while performing their experiment.
A rule of thumb for using regular dishes in an experiment is this ; If you can eat the experiment, then use regular glasses. It is easy to fill a glass with baking soda and water and watch it erupt, but it is much better if you go to designate glassware for experiments. Teach your children that, in all things, it should be "safety first." There are definitely risks involved in using regular glassware that range from harmful to uncomfortable.
Chemistry experiments can involve handling hazardous or poisonous materials that could affect you if they are ingested. There is no guarantee that washing the dishes with extremely hot water in the dishwasher will remove all of the residue. Heavy metals and other residues may remain on glasses that, by appearances, look perfectly clean.
Regular glassware should not be used when heat is involved in the experiment. Most glasses are made to hold warm or cold liquid and are not tested for higher temperatures. Extremely hot liquid could cause the glass to shatter. Scientific equipment is not expensive and is developed to handle the heat involved in chemistry experiments.
Some chemistry experiments include microbes. While the human body deals with microbes regularly, it is healthier to limit extra external encounters. Use petri dishes for this type of experiment.
The temptation to estimate the amount of chemicals in an experiment is strong. Glassware from the cupboard have different dimensions that beakers and cylinders, as do kitchen measuring tools. It is easy to end up with way too much of the chemical which can skew the results of the experiment or cause a dangerous reaction. Sometimes, not only should you avoid your drinking glasses, you should avoid any glass that wasn't made for chemistry experiments.
This risk is simply an "ewww" factor. If glasses are marked as experiment glasses, no one is going to come along and drink or eat your science experiment. It doesn't have to be dangerous to be yucky!
Even though some experiments, like salt crystals, are safe to do with your kitchen glasses, it is still better to designate special glassware for chemistry experiments only. It is better to be safe than sorry.