It is prudent to minimize all chemical exposures. Few laboratory chemicals are without hazards, and general precautions for handling all laboratory chemicals should be adopted, in addition to specific guidelines for particular chemicals. Exposure should be minimized even for substances of no known significant hazard, and special precautions should be taken for work with substances that present special hazards. One should assume that any mixture will be more toxic than its most toxic component and that all substances of unknown toxicity are toxic. Avoid inadvertent exposures to hazardous chemicals by developing and encouraging safe habits and thereby promoting a strong safety culture.

1) Plan ahead

• A risk assessment analysis must be carried out before any experiment begins.
• Get Safety Data Sheet (SDS) for chemical handling/chemicals you are goig to work with. SDS gives information such as physical data (melting point, boiling point, flash point, etc.), toxicity, health effects, first aid, reactivity, storage, disposal, protective equipment, and spill-handling procedures. Safety data sheet (SDS) are available in the KLARA chemical database.

2) Minimize exposure to chemicals

• All work with substances which are flammable or hazardous to health should be carried out in fume hood or using similar protective equipment.
• Do not allow laboratory chemicals to come in contact with skin.

3) Do not underestimate hazards or risks

• Always label all preparations and reagent vessels clearly with the name of the chemical, use an appropriate pictogram according to CLP (Classification, Labelling and Packaging).
• Each chemical container, whether supplied by a vendor or produced in the laboratory, must include labels that clearly identify the hazards associated with that chemical.
• Remember that even test tubes, beakers, etc. which will be stored and waste bottles should be labeled with the appropriate pictogram.

4) Be prepared for accidents

• Before beginning an experiment, know what specific action to take in the event of accidental release of any hazardous substance. Post telephone numbers to call in an emergency or accident in a prominent location. Know the location of all safety equipment and the nearest fire alarm and telephone, and know who to notify in the event of an emergency. Be prepared to provide basic emergency treatment. Keep your co-workers informed of your activities so they can respond appropriately.

Every laboratory experiment generates some waste, which may include such items as used disposable labware, filter media and similar materials, organic solvent, aqueous solutions, and hazardous chemicals. Read more: 8. Waste handling.