Chemical fume hoods are used to contain and exhaust chemical vapors. They come in a variety of types and designs and are used for many different operations. When using a fume hood, it is important to have proper airflow, in order to avoid release of chemical vapors from the face of the hood into the worker’s breathing zone. LTS offers face velocity measurement and smoke containment visualization as a means of documenting a fume hood’s performance and for comparison to current standards (ANSI/AIHA, SEFA). This testing and certification procedure is a part of a lab’s chemical safety management program.