Workplace Safety and Occupational Health in the Laboratory
Laboratory safety rests on a hierarchy of controls: eliminate the hazard, substitute a safer material, engineer the risk out (fume hoods, splash guards, eyewash stations), then rely on administrative controls (SOPs, signage, training, permits) and finally personal protective equipment (PPE) as the last line of defence. Candidates must know the meaning of common hazard signage (GHS pictograms such as corrosive, flammable, acute toxicity, health hazard) and Safety Data Sheet (SDS) structure, including Sections 2 (hazards), 4 (first aid), 5 (firefighting), 6 (spill response) and 8 (exposure controls and PPE). Understand risk assessment as likelihood multiplied by consequence, and know that risk controls must be reviewed when a procedure, chemical or person changes.
Traps to watch: PPE is never the first control; a lab coat is not fire-resistant unless rated; gloves are chemical-specific and breakthrough time matters; safety glasses are not splash goggles. Know emergency actions: for a chemical splash to the eye, use the eyewash for at least 15 minutes and remove contact lenses if easy; for a large spill, evacuate, alert, and consult the SDS rather than mopping immediately. Know the difference between a hazard (source of harm) and a risk (chance of harm).
Worked example: A technician must decant 200 mL of concentrated hydrochloric acid. Applying the hierarchy, engineering controls (fume hood) come before PPE (goggles, face shield, acid-resistant gloves, apron). The correct answer sequence starts with the fume hood, not with donning gloves.
Rule of thumb: control the hazard at its source before protecting the worker.