Warning! According to the harmonised classification and labelling (CLP00) approved by the European Union, this substance is very toxic to aquatic life, is very toxic to aquatic life with long lasting effects, is harmful if swallowed and is suspected of causing cancer.

Additionally, the classification provided by companies to ECHA in REACH registrations identifies that this substance is a flammable solid.

Source and more information: https://echa.europa.eu/substance-information/-/substanceinfo/100.001.863

Naphthalene is an organic compound with formula C10H8. It is the simplest polycyclic aromatic hydrocarbon, and is a white crystalline solid with a characteristic odor that is detectable at concentrations as low as 0.08 ppm by mass.[15] As an aromatic hydrocarbon, naphthalene's structure consists of a fused pair of benzene rings. It is best known as the main ingredient of traditional mothballs. Source and more info: https://en.wikipedia.org/wiki/Naphthalene