In addition, some pyrophoric materials are stored under kerosene (or other flammable solvent); therefore the use of a fume hood (or glove box) is required to prevent the release of flammable vapors ...

You work with hydrofluoric acid, with nanomaterials, with ethidium bromide, with a chemical with acute or chronic toxicity, with a caustic chemical, a flammable solvent or with a chemical that is new ...