The chemical formula of 502 glue is CH2=C(CN)-COO-C2H5. It is a colorless, transparent, low-viscosity, flammable liquid. It has a single component and no solvent. It has a slightly irritating smell and is easy to evaporate. It has weak tear-inducing properties. It is a one-component instant-curing adhesive synthesized through advanced production technology, based on α-ethyl cyanoacrylate, with added tackifiers, stabilizers, tougheners, polymerization inhibitors, etc. It has a certain degree of toxicity, but the toxicity will be reduced after curing. However, 502 glue is a cyano compound after all, and it will produce toxic substances after decomposition. It is catalyzed when it encounters moisture and moisture, and quickly solidifies and adheres. Non-toxic after cured. You can use a wet hot towel to apply on the tea cup. After ten minutes, the cured 502 will soften and it can be removed. If a small area is covered with 502 glue, just soak it in hot water. If a large area is covered with 502 glue, apply acetone and wait for about 5 to 10 minutes to remove it.