Shoes - Wear shoes that completely cover the feet. Wearing proper PPE while working in the laboratory is required by state and federal regulations and is highly recommended by industry and academic standards of good practice. The LSP has information on lab safety, PPE, and chemical hazard assessment information. This information should be added to written lab procedures or safety SOPs. Incidental contact to the skin can result in painful burns that penetrate deeply and are slow to heal.
More substantial danger rests in the unique properties of hydrofluoric acid.
Undissociated hf penetrates the skin. When absorbed it dissociates rapidly into the fluoride ion, damaging underlying tissue. As a result, cell membranes collapse and nerves will fail to function, leading to fatal pulmonary edema. These units are available from many vendors. The problem with standard or domestic type refrigerators and freezers is the variety of ignition sources such as lights, switches, and defrost coils, that are present in these units.