A ductless fume hood is a containment device used in laboratories to protect users from inhaling hazardous fumes, vapors, or particles. Unlike traditional fume hoods, which require external ventilation systems, ductless fume hoods filter air internally using various methods such as activated carbon or HEPA filtration. This makes them more flexible and cost-effective, as they can be placed anywhere without the need for complex ductwork. Ductless fume hoods are ideal for smaller laboratories or areas where traditional ventilation is impractical.