White Island New Zealand – December 2019
Extract from ‘Geology & Hazards’ – 
Volcanic Gases:

  Gases are continually emitted from the craters and fumaroles on White Island, at rates of several hundred to several thousand tonnes per day. These gases are mostly steam, carbon dioxide and sulphur dioxide, with small quantities of halogen gases (chlorine and fluorine). The acid gases combine with water in the steam/gas clouds to form liquid acid droplets which sting the eyes and skin, and affect breathing. They also severely damage cameras, electronic equipment and clothing. Visitors to White Island should avoid steam/gas clouds, and watch for wind changes that could blow clouds in their direction.
Gas masks with acid gas filters are advisable  MORE

Full text ⇒ HERE

“… I am interested that reporters are not discussing Hydrogen Fluoride gas emissions
from this volcano
that is known to emit 1500 to 2000 kilogram of HF gas each day,
when it is in its “quiet” mode. Hydrogen fluoride 
inhalation has caused death
in numerous industrial accidents, usually within 24 hours and
burns to the skin from this gas have claimed victims some
days later… “  Dr Geoff Pain → HERE

 ” Volcanic eruptions may also affect the climate, especially if there are
many large-scale eruptions over a short space of time which
add volcanic dust and fluorides to the atmosphere.”

Fluoride Accident South Korea

Several workers at the Hube Global chemical plant
died in a massive hydrogen fluoride leak.

SEE ALSO  [Very comprehensive]