Lab accident

Working in a chemistry lab involves risks, usually due to the reagents/equipment used or lack of experience with said reagents or lab equipment. Lab accidents can result from a variety of factors, with the human component being the most common.

Lab accidents are described in various reports which can be found online.

Types of accidents

• Minor: Most common type of lab accident, involves little material damage and/or minor injuries. They can result from improper use of equipment or storage of sensitive reagents. Examples: burns (either chemical or hot bodies), thermal runaways, volatile liquid bottle popping, corrosion of metal objects, etc.
• Major: Will cause appreciable material damage to equipment and fittings, and may cause serious body damage. Known major accidents include reaction vessels shattering during reaction and splashing their content in the fume hood/lab, small explosions, toxic leaks, severe rusting of metal objects from all around the lab, etc.
• Catastrophic: Lead to high or complete damage of the lab, and serious injury or on rare occasion death. Common examples include fires, floods, explosions, etc.

Common lab accidents

Chemical leaks

If the reagent bottle is not closed properly, volatile chemicals will slowly evaporate from the bottle and their vapors will fill the lab area. Gas leaks are particularly dangerous, as they can also carry the risk of explosion.

Electrocution

Touching active apparatus with faulty electric insulation or lack of grounding can lead to electrocution, which is most of the time harmless, though if the amperage is high enough it may lead to cardiac arrest.

Static charge can sometimes build on one's clothes after constant rubbing your coat against itself and wearing relative insulating shoes. This is noticeable when touching a grounded metal object, like a pipe or a door knob. While harmless, this phenomenon carries a risk of fire when handling extremely flammable solvents.

Fires

Fires can appear if you're using an open flame near combustible materials. Generally it's recommended you use hotplates or heating mantles when handling flammable solvents. Flammable materials or energetic mixtures will burn release large amounts of smoke.

Glassware cracking

Glassware of poorer quality may crack if heated too much. The content of the vessel will spill all over the work area and generally require extensive clean-up. If the content of the vessel is corrosive or pyrophoric, the spill may lead to severe property damage or even injury to the chemist.

Incompatible chemicals explosion

When accidentally mixing incompatible chemicals, an explosion may occur. This tends to happen when chemical wastes are added in the wrong container (oxidizer in a combustible container e.g.), or due to improper storage of the said reagents (nitromethane and an amine e.g.).

Runaway reactions

Reactions running uncontrollably fast can be problematic. Most often, such reactions result in uncontrollable foaming and spilling of foamed liquids on the lab table. This can result either from gas evolution or boiling (the latter results from exothermic reactions in liquid medium). This can be dangerous if the spilling liquid is hazardous. More rarely, the evolving gas is hazardous.

Some reactions prone to runaway are the following:

• Iron + concentrated nitric acid (overheating, uncontrollable foaming, evolution of nitrogen dioxide)
• Carbonates + strong acids (uncontrollable foaming and spillage)

Vacuum flask rupture

If vacuum flasks have microfractures, they may implode when subjected to high vacuum.

Another type of accident occurs when a liquid nitrogen cooled vacuum flask/trap is removed from the vacuum pump and rapidly warmed. The thermal shock is enough to weaken the glass, while the rapid expansion of the gas inside is enough to cause an explosion.

Idiots or pets wandering by

If you do not have dedicated lab space that is off-limits to anyone not knowing or understanding chemistry, be prepared for something like that. Your cat can overturn a beaker, your grandma can confuse your sulfuric acid for plant oil, your alcoholic neighbor can steal methanol thinking it's ethanol. For idiots, the solution is clear and comprehensible labeling, but it won't protect against animals for obvious reasons.

Uncommon or rare lab accidents

Earthquakes

If the lab equipment and furniture is not properly secured, a strong earthquake can seriously damage the lab. Glassware and reagent bottles are the most vulnerable. If bottles with incompatible chemicals are broken and their content mix, there is a risk of fire or explosion.

Floods

Floods can appear either due to a leak in the water plumbing or in rarer cases from an outside source. If your lab is in the basement, it may be completely flooded. Any open bottles, beakers will be washed by the water, and salts will get dissolved in water, spreading the dissolved reagents throughout the lab. Airtight containers/closets will float if they're not heavy enough or bolted to the wall or floor and will damage other lab equipment. Glassware may be broken if floating objects hit them. The problems however, don't end with removing the water from the lab. Dissolved reagents are now everywhere and extensive cleaning is required. Steel objects will rust in air and will require either cleaning or replacement.

Prevention

Lab accidents can be prevented by following the safety protocols properly and always wear proper protection equipment, even when dealing with "harmless" chemistry. A good tip is to keep things as simple as possible and never overload yourself with unnecessary tasks. If you feel like you could screw up, take a break and think twice what you're doing. Better safe than sorry.

References

Relevant Sciencemadness threads

• Life after detonation
• Bad days in the lab or with glassware?
• First Major Lab Accident
• When Chemistry Goes Wrong