I will preface this post that for all the good work scientists do, there is a great deal of potential stored in science labs. Potential discoveries that may one day cure terrible diseases, amazing technologies we haven't yet thought of, and potential death.
This post will explore some of the most terrifying things known to Science by @holoz0r.
Asbestos Tiles, from your Butler Miles.
These are used in close conjunction with the Bunsen burner. Asbestos is considered to be fireproof. It won't let fire spread. There's one downside to incredible fire retardant properties of asbestos.
As a fibre, when inhaled, it causes a terrible cancer known as mesothelioma. The impacts of this cancer typically take forty or so years to develop. There's a large number of patients in Australia suffering from this affliction due to the use of asbestos in much building material.
Do not cut, or rub against a cheese grater. You, and those around you will suffer.
Tina Turner, The Bunsen Burner
This terrifying instrument is used to typically heat flasks and do other things where flames are required in science. This can be, for example, to determine the caloric content of food, or to speed up a chemical reaction. Or, in my case, to cause the release of panicked pheromones and neurotransmitters saying "Watch out, your beard will burn."
The Bunsen Burner works by allowing a gas of some sort to burn, heating things to enormous temperatures, with the flame itself, once correctly "calibrated" able to burn through almost anything.
When they produce an invisible flame, hot enough to eventually boil water, you know you're dealing with a very serious piece of danger.
Your Own Lungs
If you're worried about breathing in fibrous substances that could cause cancer, how about noxious gases that can cause you become violently ill straight away? Or, having them fill with carbon dioxide; preventing the haemoglobin in your body from distributing oxygen around the place?
There is a lot of stuff that can be inhaled (even helium is generally not considered safe!) for amusing impact, or for genuine medical reasons; but your lungs should not be employed as a tool in the lab. Leave your lungs closed, or use a mask, or a fume cabinet.
Chemicals
Everything around us is made of chemicals. You are made of chemicals, and are a living, moving chemical; biological reactor. There's particularly dangerous chemicals available in a lab, and the ones most people are terrified of are acids. These are great and all, for their industrial applications in dissolving things. However, more terrifying are bases, on the basis that people don't consider them to be as violent as acids. They are. I don't have any examples other than sodium hydroxide because I'm not a chemist, but this is definitely something you shouldn't consider adding to your vodka lime soda.
I didn't pursue a scientific career, but sometimes I wish that I did. There is so much general knowledge you can obtain from understanding how the world works on an elementary level, which is scientific. It is practical knowledge.
It is never to late to learn, because the longer you wait, the greater the sum of knowledge becomes.
Image Sources:
Bunsen Burner
Encounter Suits