Acids will cause severe burns that produce charred skin. Equally important is the risk of compressed gas cylinders exploding under high heat or if damaged. Health Hazards are hazards that have a direct impact on worker health. The gas or vapor that replaces the oxygen does not have to be toxic in order to kill the worker - it simply replaces the oxygen with something that will not support life. This doesn't necessarily mean 4 legged babies.
Human teratogens are rare, but do exist in many workplaces.
Women of child bearing age, those who are pregnant, or who plan on becoming pregnant in the future should always minimize their exposure to any chemical materials.