There are many vintage fire extingushers on sale 'The 'old brass' types may still contain carbon tetracholride.
Carbon tetrachloride is a probable carcinogen. Inhalation and ingestion are harmful, and may be fatal. Irritant, skin contact may lead to dermatitis. Long-term exposure may lead to kidney or liver damage, cancer and damage to eyes, skin and lungs.
When heated, (CTC) produces a potentially leathal gas, phosgene. It's toxic hazardous stuff rupturing the blood vessels of the lungs.
The green CFC extingushers loved by motor racing types have been banned for several years, circa 2003. The container may be green but the CFC is known to damage the ozone layer. It is not too healthy to breath CFC either.
You have been warned