Dangerous goods (or hazardous materials) are solids, liquids or gases
that can damage people, other living organisms or the environment and
they need to be controlled with chemical regulations. These hazards
include materials that are radioactive, flammable, explosive, corrosive,
oxidizing, asphyxiating, biohazardous, toxic, pathogenic or allergenic.
Here is a list of the categories in which these hazardous materials are
- Class 1: Explosives -> dynamite, nitroglycerine…
- Class 2: Gases -> inflammable gases (acetylene, hydrogen…), non
inflammable one (nitrogen, neon…) or poisonous ones (fluorine,
- Class 3: Flammable liquids -> diethyl ether, carbon disulfide,
- Class 4: Flammable solids -> nitrocellulose, magnesium, white
- Class 5: Oxidizing agents and organic peroxides -> calcium
hypochlorite, ammonium nitrate, hydrogen peroxide, cumene
- Class 6: Toxic and infectious substances -> biohazards (human
material, virus cultures…), potassium cyanide, mercuric chloride,
- Class 7: Radioactive substances -> uranium, plutonium…
- Class 8: Corrosive substances -> acids (sulfuric acid,
hydrochloric acid…) and bases (potassium hydroxide, sodium
- Class 9: Miscellaneous -> asbestos, air-bag inflators, self
inflating life rafts, dry ice…
Each hazard can be denoted with a specific sign, which is used to know
the risks of using each chemical substance.
Personal protective equipment in the laboratory includes gloves,
respiratory protection, eye protection and protective clothing. The need
for each type of protection depends on each specific case, type of
operations, nature of the chemicals and the amounts used.
- Protective gloves should be worn when handling irritant, harmful
and corrosive materials, chemicals of unknown toxicity and very hot
or very cold materials. Gloves used in the laboratory are normally
made of latex, vinyl or nitrile.
- A respirator may only be used when ventilation is necessary and
the fume hood does not reduce the harm of the chemical under
- Safety glasses are used to protect your eyes from flying
particles, glass or powders among others.
- Protective clothing such as lab coats, which resist physical and
chemical hazards, should be worn. Shorts, open shoes, ties and
unrestrained hair should be avoided.
In the case of biohazards, four categories are found: the lowest one
(Level 1) corresponds to the minimum risk and the highest one (Level 4)
corresponds to the maximum risk. In the minimum risk, it is enough to
work with gloves and some facial protection. In contrast, Level 4
requires specific precautions such as wearing a positive pressure
personnel suit with a segregated air supply, taking several showers,
utilization of a vacuum room, an ultraviolet light room or an autonomous
Acid and base