ASNT Level III- Visual & Optical Testing

7.3.2 Safety Precautions
Etchants are solutions of acids, bases or salts in water or
alcohol. Etchants for macroetching are water based. Etching
solutions need to be fresh and the primary concerns during
mixing are safety concentration and purity
Safety precautions are necessary during the mixing and
use of chemical etchants. Chemical fumes are potentially
toxic and corrosive. Mixing, handling or using etchants
should be done only in well ventilated areas, preferably in an
exhaust or fume hood. Use of an exhaust hood is mandatory
when mixing large quantities of etchants. Etching large
areas requires the use of ventilation fans in an open area or
use of an exhaust hood. Contact of etchants with skin, eyes or clothes should
beavoided. When pouring, mixing or handling such chemicals, protective
equipment and clothing should be used, including but not limited to glasses,
face shields, gloves, apron or laboratory jacket. A face-and-eye wash fountain
is recommended where chemicals and etchants are sorted and handled. A
safety shower is recommended when large quantities of
chemicals or etchants are in use.
Charlie Chong/ Fion Zhang