Safety in the laboratory
An Analytical Chemistry laboratory contains chemical products, solvents, acids, electricity, gas, glass equipment etc. and so is potentially dangerous.
Being unaware of the properties of reagents and substances, not knowing how to use the equipment properly, or failing to observe the safety norms in a laboratory can be a source of danger for you and everyone present.
Dangers and risks
The kind of work that is done in a chemistry laboratory inevitably involves using chemicals (reagents, products and substances) as well as equipment and utensils. The dangers are therefore related to:
- physical agents (noise, vibration, microclimate, microwaves);
- chemical agents (inhaling smoke or dust);
- biological agents (swallowing or inhaling dangerous substances).
There is also a series of related health and safety issues resulting from the actual tasks that are carried out in a laboratory. There is the risk of an accident (which may or may not imply trauma with actual physical lesions) or risk related to hygiene or the environemnt (exposure to agents and/or harmful substances potentially present in a laboratory).
To ensure that experiments or analytical measurements are carried out correctly, the workbench and equipment need to be kept scrupulously clean and everything kept neat and tidy. To avoid potential danger, it is important that everyone is aware of the correct methods, techniques and procedures to be used, understands how to use the equipment and has a working knowledge of the properties of the most commonly-used chemical substances and materials.
All chemical substances found in a laboratory are potentially dangerous.
One of the most recent classifications of chemical substances and how dangerous they are is contained in the Ministerial decree of 16 February 1993, detailing norms regarding the classification, packaging and labelling of dangerous substances in line with new directives from the Council of the European Commission.
The classification system uses a letter which represents a symbol and / or the risk associated with the particular substance.
Classification of chemical substances
Example of what the label on a reactive product looks like
In the laboratory, it is absolutely essential to observe the safety norms listed below.
- Locate all emergency equipment (where to wash eyes or skin in an emergency, first-aid kit, fire-extinguishers, gas masks, escape routes etc.). If in doubt, ask about use of any of the above.
- Always wear an overall to protect your clothing and safety glasses to protect your eyes from splashing when decanting liquids or solvents, or when extracting substances using solvents, or when containers accidentally break.
- Do not run or play around in the laboratory; you may bump into someone and cause serious problems.
- Consider that any product handled in a laboratory is potentially poisonous. Never taste anything or touch anything with bare hands, always use a spoon or spatula. Never smell powders or solvents. If anything accidentally gets in your eyes, keep them open and rinse for 15 minutes. If skin comes into contact with chemicals, acid burns should be treated using a solution made from diluted bicarbonate of soda (other substances must be avoided). For burns resulting from contact with strong base solutions, try applying a weak acid solution, for example a 2% acetic acid solution, a 25% vinegar solution or a 1% boric acid solution.
- Always keep your own and communal work areas clean (scales, store cupboards, instruments etc.).
- To be on the safe side, handling of any substance or performing of any reaction should be done under an efficent extractor hood but this is of vital importance if the reaction produces acid or foul-smelling gas or when compounds and/or solvents being used are known to be toxic or inflammable.
- Do not touch glassware that has been over a stove or in an oven without crucible pliers. Glass objects show no visible sign of being hot until they reach temperatures of 200°-300° so cannot be distinguished from objects at room temperature.
- Never use your mouth to fill a pipette but a proper pipette filler.
- Never use or handle substances which have no label to identify them.
- Make sure that organic solids are kept away from direct sources of heat, and “unsafe” electrical appliances.
- Never throw organic solvents or solutions containing toxic substances down the sink or into the sewage system to avoid environemental damage. If you do not know where to dispose of anything, ask the laboratory personnel.
- Always be aware of what you are doing and why, and never confuse one substance with another. Always label the contents of any container using a marker pen or label. This is useful if you have to break off between one stage of the experiment and another. It is indispensable if you have to leave your work for several days.
- Get a notebook where you can record all your data regarding structure formulae, molecular weight, weight in grammes, moles of product before and post reaction, amount of solvent used, kind of equipment used, experimental conditions, symbols of products used and date.