Chemical and Biological Risks in the Laboratory

Laboratory safety: why is the quality control laboratory assessed separately?

In a plastics, paint or chemical plant the production line works on a tonne scale, while the laboratory works in millilitres. This difference in scale leads to the laboratory being overlooked in the risk assessment: "There are very few chemicals here." Yet in laboratory safety the problem is not quantity but variety. Acids, bases, solvents, oxidisers, pressurised gas cylinders, hot plates, ovens and samples whose contents are not fully known all sit together in the same room.

Art. 7 of the Regulation on Health and Safety Measures for Work with Chemical Substances requires the same order of measures in the laboratory: substitution of a hazardous chemical with a less hazardous one, carrying out work with the smallest number of people and the smallest quantity, appropriate engineering controls and ventilation, and personal protection last. The same article also lists preventing contact between chemicals that may react with each other.

On the building side, Art. 72 of the Regulation on the Fire Protection of Buildings requires emergency lighting in workshops and laboratories containing chemical substances. The laboratory should therefore be treated as a separate section in the plant's risk assessment.

Using a fume cupboard: right and wrong

The fume cupboard is the laboratory's most important engineering control, but it gives no protection when used incorrectly. The basic rules for using a fume cupboard:

• Sash (glass) height: Work is done at the safe sash height marked by the manufacturer. If the sash is left fully open, the air velocity drops and vapour can escape towards the worker.
• Working depth: Work is done at least 15 cm inside the front edge. Working close to the front edge increases the chance of vapour escaping.
• Head outside: The head and body are not put inside the fume cupboard.
• Not a store: The fume cupboard is not used as a bottle store. Clutter inside disrupts airflow and increases the chance of spills.
• Airflow indicator: If the fume cupboard has an airflow indicator or alarm, it is checked before each use; a cupboard in alarm is not used.
• Fan failure: If the extract fan is not running, the fume cupboard gives no protection. What to do in case of fan failure and power cuts is written into the instructions.

Annex III of the Regulation on Health and Safety Requirements for the Use of Work Equipment requires ventilation and air-conditioning installations to be periodically inspected once a year for conformity with their design. We recommend covering the extract system to which the fume cupboard is connected in this inspection plan, and having the fume cupboard's own performance check carried out at the intervals given in the manufacturer's instructions.

Gas cylinders: securing, storage and lines

Nitrogen, argon, helium, hydrogen, acetylene and synthetic air cylinders used in analytical instruments are the laboratory's most frequently overlooked risk. If the valve of a toppled cylinder breaks, the cylinder can be propelled uncontrollably.

1. Every cylinder is upright and secured to the wall or a fixed stand with a chain or clamp.
2. Valve protection caps are kept on unused cylinders; cylinders are not carried without caps and are moved on a cylinder trolley.
3. Only the cylinders used that day are kept in the laboratory; spares are kept in the outdoor cylinder store.
4. Flammable gases (hydrogen, acetylene) and oxidising gases (oxygen) are kept apart.
5. The regulator suits the type of gas; connections are checked for leaks with a foaming liquid.
6. Gas detection is considered in rooms where toxic or flammable gases are used. In small, poorly ventilated rooms, leaks of inert gases such as nitrogen and of liquid nitrogen can cause oxygen depletion.

For storing incompatible substances separately, see our article on chemical storage compatibility.

Laboratory chemical safety: inventory, labelling and storage

Laboratory chemical safety starts with knowing what your chemicals are. The arrangements to set up:

• Inventory: Every chemical in the laboratory is listed with its name, quantity, location and safety data sheet. We explained how to keep the inventory in our article on preparing a chemical inventory.
• Safety data sheet: Turkish-language SDSs are kept in the laboratory where workers can easily reach them. For how to read them, see our article on how to read a safety data sheet.
• Labelling: Every solution and sample container decanted from the original packaging is labelled with its contents, concentration, date and the person who prepared it. No unlabelled bottle stays in the laboratory. For the meaning of pictograms, see our article on chemical labels and pictograms.
• Bench quantity: Only the quantity needed for the day's work is kept on the bench; solvents are kept in a flammables cabinet.
• Waste: Chemical waste is collected in separate, labelled containers with compatibility in mind; it is not poured down the sink.

Sample-related risks: the bottle of unknown contents

A sample arriving at the quality control laboratory is not always innocent. A hot sample taken from the process, a container under pressure, a mixture whose reaction is not complete, or an unlabelled bottle from a customer are a significant source of laboratory accidents.

Rules for sample receipt:

• A sample is handed over with its contents, the point it was taken from, its temperature and known hazards stated; the sample is not opened without this information.
• Hot and pressurised samples are opened in the fume cupboard after waiting for them to cool and for the pressure to be relieved.
• A sample of uncertain contents is treated according to the most hazardous possibility.

On the biological side, laboratories carrying out microbiological testing of products such as food, water or cosmetics fall within the scope of the Regulation on the Prevention of Risks from Exposure to Biological Agents. Under Art. 18, in laboratory work whose main purpose is not working with biological agents but which involves materials of uncertain content, at least containment level 2 measures are applied. If work is deliberately done with a known agent such as a reference strain, the containment level is determined by the risk assessment and the agent's risk group. Aerosol-generating operations such as centrifuging, mixing and pipetting are done in a suitable cabinet; culture waste is made safe before disposal. For the meaning of risk groups, see our article on biological agents and risk groups.

Laboratory accidents and first response arrangements

Most laboratory accidents fall into a few recurring types: chemical splashes to the eyes or skin, cuts from broken glass, burns from hot plates and ovens, small solvent fires and inhalation of vapours. Preparation for each must be inside the laboratory:

• An eyewash and, where needed, a body shower are within quick reach of the point where chemicals are used and are tested regularly by running them.
• The chemical spill kit is chosen to suit the types of chemicals used in the laboratory.
• The extinguisher is chosen to suit the types of fire in the laboratory, and workers know how to use it.
• There is a separate, puncture-resistant container for broken glass.

We explained the steps to follow for larger spills in our article on chemical spill response.

Choosing laboratory PPE and the basic rules

The choice of laboratory PPE depends on the task; a single "laboratory kit" does not cover every job. Under the Regulation on the Use of Personal Protective Equipment at Workplaces, the choice is made according to the risk assessment.

Basic laboratory rules:

1. Eating, drinking and using cosmetics in the laboratory are prohibited; food is not stored in the laboratory refrigerator.
2. Closed shoes are worn and long hair is tied back.
3. No mouth pipetting.
4. No lone working in the laboratory for high-risk tasks.
5. When work is finished, the bench is cleaned and hands are washed.

When carrying out risk assessments at chemical and plastics businesses in Bursa and the surrounding provinces, Bursa Sistemer OSGB treats the laboratory as a separate section and, as part of OHS specialist services, links inventory and fume cupboard checks to site walks. We plan workplace exposure measurements with authorised laboratories. The general risk list for the sector is on our chemicals and plastics sector page.

Frequently Asked Questions

How far open should the fume cupboard sash be?

At the safe working height marked by the manufacturer. When the sash is fully open, the air velocity drops and vapour can escape towards the worker. Work should be done at least 15 cm inside the front edge.

How should gas cylinders in the laboratory be secured?

Upright, secured to the wall or a fixed stand with a chain or clamp. The valve cap is kept on unused cylinders; only cylinders in use are kept in the laboratory, and spares are kept in the outdoor store.

Does the quality control laboratory fall under the biological agents regulation?

Yes, if microbiological analysis is carried out. In laboratory work whose main purpose is not working with biological agents but which involves materials of uncertain content, at least containment level 2 measures are applied.

Can a laboratory coat be worn outside the laboratory?

No. The coat carries chemical and biological contamination to the canteen and offices. It is hung at the laboratory entrance and laundered in the manner set by the organisation.