Chemical compounds possess several hazards. When working with chemical always look for substitution for a safer compound, read the label carefully and consult the safety data sheet.
Activities with biological material are separated in 4 class, related to the hazard of the strain manipulated, the scale of the activity, the steps, etc.
Compressed gas cylinders combine a physical hazard (high pressure) with a chemical one such as: inert/asphyxiting gases; flammable gases; oxidizing gases; toxic &/or corrosive gases
Most lasers can cause eye and skin injuries to anyone who is exposed to the direct beam or its reflections.
Material whose 50% (at least) particles have one or more dimensions within 1 to 100 nm in size. Nanomaterials can be more harmful than their bulk counterpart.
Frequently used for cooling systems, cryogenics combine, as for compressed gases, both chemical and physical hazards.
Magnetic fields generated by magnets are more and more powerful and involve a non negligible risk which must be mitigated.
All radioactive activity is monitored and regulated as per legal bases. It is mandatory to follow measures and procedures indicated for any work with radioactive sources.