I used HF to clean the surface of a copper scattering cell (block of copper with an internal chamber and some access ports, about 5 inches high and 4 across).

Burn cream on hands, two pairs of gloves, one silk one leather, leather apron and splash goggles. Comes packed in a plastic container which is secured to a small wooden pallette with the bottle held upright in a box with wooden batterns. Impressive warning signs.

OA has solved the mystery of why we had to use these precautions!