Chemical hazards

Three main legal basis rule the use of chemicals in Switzerland: the Chemical Act (ChemA), the Chemical Ordinance (ChemO), and the Chemical Risk Reduction Ordinance (ORRChem). These legal basis are complemented by recommendations provided by the Federal Commission of coordination for safety at work (FCOS) and by the SUVA.

Given the hazardous nature of chemicals, the EPFL internal directives follow closely these laws and requirements, and provides best laboratory practices for the safe use, storage, and disposal of chemicals.

For any support, or complementary information, contact us.

In case of chemical incident

Call the 115 or +41 21 693 30 00

On the eyes

  • Ask a colleague to guide you towards the eyewash station and to call the 115
  • Use the eye-washer until the bottles are empty

On the hands

  • Immediately wash with tap water and ask a colleague to call the 115. Keep washing until the intervention team arrives.

On the body

  • Go under the security shower immediately and, under the running water, remove your soiled clothes. Ask a colleague to call the 115
  • Go under a shower (e.g., in a changing room, locker,…) with a mixer tap and curtain. There you can keep rinsing while removing remaining clothes at a more comfortable temperature. Follow the instructions of the intervention team.

In case of a spill

  • Call the 115. Only the intervention team deals with spill.

Chemical hazards and GHS pictograms

Interestingly, the very properties that make a chemical useful are often those that make it risky to use, so you must learn how to safely use chemicals that have significant inherent hazards.

The Globally Harmonized System of Classification and Labelling of Chemicals (GHS) is now used to define physical , health , and environmental hazards  for each chemical manufactured and sold.

It is the responsibility of the manufacturer or importer to identify and communicate the hazard(s) of each chemical they produce or sell. It is up to the user (you) to understand the information provided on the label and in the Safety Data Sheet (SDS)

The GHS is all about communicating hazards to users.

Pictograms are pictures that represent a concept. The GHS uses nine pictograms to visually alert users to the chemical’s hazard class. GHS pictograms, along with the hazard classes they cover, are shown below. For more information, please read the “what should I know” series that provide extended information about GHS classification and labelling.

“What should I know”:

Acute toxicity (fatal or toxic)


Aquatic toxicity

Skin corrosion
Eye damage
Corrosive to metal

Organic peroxide

Compressed gas
Liquefied gas
Dissolved gas
Refrigerated liquefied gas

Emits flammable gas
in contact with water
Organic peroxides

Reproductive toxicity
Respiratory sensitizer
Target organ toxicity
Aspiration toxicity

Irritant (skin and eye)
Skin sensitizer
Acute toxicity (harmful)
Narcotic effects
Respiratory tract infection
Hazardous to ozone layer

Working with chemicals

You will work with many hazardous chemicals at some stage of your work. How can you be expected to know the hazardous characteristics of so many different chemicals?

The first safety procedure when working with a chemical is ALWAYS to: 

  • look for substitutions with less hazardous chemicals
  • read the label
  • read the safety data sheet
  • Wear safety glasses, gloves and a lab coat, or other personal protective equipment required for your procedure.
  • Do not work alone. If you are alone in the lab or you are working during off-hours or weekends, follow the off-hours announcement procedure.
  • Be prepared for emergencies and know what action to take. Make sure that necessary supplies and equipment are available for handling small spills.
  • Whenever possible, use a fume hood.
  • Never let reactions run unattended unless they are well understood and a system to contain spills is in place (ex: in the event of power failure). A safety form for experiments left unattended must be displayed on the fume hood sash.
  • Wash hands with soap and water immediately after working with any laboratory chemicals, even if gloves have been worn.

Most commercial substances have detailed information prepared by the supplier, the Safety Data Sheet (SDS). The Law on chemical products (LChim) stipulates that the user is responsible for taking into account the safety information given by the supplier and taking the appropriate measures to protect themselves.

Always refer to the SDS of the supplier from where you purchased the chemical.

SDS databases:

Additionally, toxicological information can be found on those pages:

Before starting to work in a lab, read and think before acting. Imagine what could go wrong so that you are prepared in a case of an accident or an emergency.

Locate the lab phone and know the emergency number.

Locate the safety exits, the safety showers, the eye-washer, the fire extinguisher, the fire blanket, the pharmacy and the sink.

Be sure to behave correctly in case of an evacuation (gas or fire).

Never work alone.

Some chemicals (e.g., Pb, Hg,…) require medical supervision. In this case, our hygienists and our occupational health doctor will monitor you.

It is mandatory to wear Personal Protective Equipment (PPE) whenever you are in a chemistry lab:

  • A cotton lab coat with pressure buttons
  • Safety glasses (corrective goggles adapted to your eyesight are payed by the EPFL)
  • Protective gloves (adapted to your work (for ex. hot or cold) and to the chemical you are working with (use our Gloves Guide to find suitable gloves)
  • Wear long trousers to protect your legs from spills
  • Wear closed shoes adapted to lab work (don’t work in flip-flops, ballerinas or high heels)
  • Attach your hair if needed

The PPE must be adapted to your work.

All PPE are available in the campus shops of the EPFL or the online shop.

The EPFL puts a lot of effort into protecting you as much as possible in your labs. Do not hesitate to contact the SCC if you notice a fault in the PPE already in place.

EPFL organizes audits, but you are in the labs all day and you should tell us about any problem or situation you think may be dangerous.

If you need special protection you can contact us for corrective measures.

When working with hydrofluoric acid (HF), you need to wear, in addition to the standard protective equipment mentioned before:

  • an apron (Haberkorn 300926)
  • a face shield (G500-GU/150 and GF-1/151)
  • thick protective gloves (Butoject 898)

Purchasing chemicals

Before ordering a chemical, review the associated hazards to ensure that appropriate safe conditions and controls are available in the lab. Dangerous chemicals require a special authorization from the SCC to be purchased, used, and/or stored at EPFL. Include these ordering procedures as a part of your process planning to increase laboratory safety.

Never buy products directly from the supplier. Order your chemicals through Catalyse

Buying the products via EPFL has several advantages:

  • The product is labelled with a bar code, which is very important for the inventory of chemicals you have to do twice a year
  • The products have a preferential price for the EPFL

Transport of chemicals

Bottle carriers or baskets should be used to transport chemicals.

Bottles should be carried one at a time with both hands, one on the neck of the bottle and the other one underneath.

Chemicals moved between sites should be in their original outer packages, or otherwise protected from breakage or damage in a secondary container with sufficient absorbent material to contain a spill.

Storage of chemicals

Have a look at our chemicals storage page