40 Fun Facts About Lab Safety

Whose 1890s laboratory notebooks are still so radioactive that they are stored in lead-lined boxes?

Marie Curie carried test tubes of radioactive material in her pocket and kept them in her desk drawer, admiring their faint glow in the dark. Even her cookbooks are highly radioactive.

Chemist Karen Wetterhahn died after a drop or two of a compound of which metal soaked through her latex gloves?

Mercury, in the form of dimethylmercury, passed through her gloves within seconds and proved fatal in less than a year. Her colleagues then tested other gloves and found it slipped through most of them too.

Chemists pour sulfuric acid into water, never the reverse, because adding water to the acid can do what?

Mixing releases so much heat that a little water can boil and spatter out of the container, carrying hot acid with it. Even done the right way round, the mixture can heat up to 80 °C or more.

Janet Parker became the last person known to die of which disease after it escaped a Birmingham university lab?

Smallpox virus grown in a research lab on the floor below her darkroom infected her in 1978. An inquiry concluded it most likely travelled up a poorly maintained service duct.

Which German chemist, blinded in one eye by a lab explosion, has a name that lives on in school lab equipment?

Robert Bunsen lost the sight in his right eye when the toxic compound cacodyl exploded, and he nearly died of arsenic poisoning as well. The burner that carries his name was perfected by 1855.

After a chemical splash, for how long should eyes be rinsed at an emergency eyewash station, at the very least?

15 minutes is the minimum, and the American safety standard requires a plumbed eyewash to keep water flowing for that long. A proper station flushes both eyes at the same time.

Physicist Louis Slotin received a fatal radiation dose when which hand tool slipped in a 'demon core' experiment?

Screwdriver in hand, Slotin was holding two halves of a neutron reflector slightly apart, a method of his own that skipped the safety shims. When the blade slipped, the halves closed and the core went critical.

Before rubber bulbs and pipette fillers, how did chemists usually draw liquid up into a glass pipette?

By mouth suction, like a drinking straw, which made swallowing the sample a real hazard. Some pipettes were made with two extra bubbles in the stem to keep the liquid away from the chemist's lips.

Which ventilated lab enclosure, used through a movable glass sash, pulls hazardous vapours away from the worker?

Fume hood designs with rising glass sashes date back to the University of Leeds in 1923. The enclosure does a second job too, containing spills and shielding the user from small explosions.

Which laboratory chemical is kept in plastic bottles because it attacks and dissolves ordinary glass containers?

Hydrofluoric acid reacts so readily with glass that it is used to etch and frost it. Oddly, chemists class it as a weak acid, even though it is very corrosive.

Sodium is stored under which liquid in a school lab to keep air and moisture away from its surface?

Mineral oil seals the soft element off from air, which would otherwise coat it in a layer of oxide. Water is the last thing to use: even a tiny amount sets off a reaction that gives out heat.

A laboratory gas burner with its air hole closed gives which colour of cooler, easy-to-see 'safety flame'?

Yellow comes from tiny soot particles glowing in a flame that is short of air, which is why it leaves carbon on whatever it heats. The hotter working flame can be nearly invisible against some backgrounds.

Which lab eye protection fits snugly against the face all round the eyes to keep chemical splashes out?

Goggles for laboratory work combine impact resistance with side shields that stop splashes reaching the eyes. Channel swimmer Matthew Webb tried an early pair in 1875 and called them 'barnacles'.

Which mild kitchen-cupboard powder do chemistry labs keep on hand to neutralise spilled acid?

Baking soda, known to chemists as sodium bicarbonate, is the usual choice for mopping up acid spills. It is not the right thing for a spilled alkali, even though it can react with both.

Before a laboratory centrifuge is switched on, its load of sample tubes must be arranged so that the rotor is what?

Evenly balanced loads matter because a small difference in mass turns into a large sideways force at high speed. That strain can damage the spindle or injure someone nearby.

A student drenched by a chemical spill should stand under which emergency fixture while removing soaked clothing?

Safety shower units pour large volumes of water over the head and body, and contaminated clothes have to come off. The flow is too forceful for eyes, which can be damaged by the pressure.

Which sheet of flame-resistant fabric hangs in a quick-release wall pack to wrap a person whose clothes are alight?

Fire blanket packs for laboratories are often made of wool treated with a flame retardant. Laid over a small blaze or wrapped round a person, the sheet smothers the flames.

In the PASS method for using a fire extinguisher, the first letter stands for pulling what out of the handle?

The pin comes out first, which also breaks the tamper seal. The other three steps are to aim low at the base of the fire, squeeze the handle and sweep from side to side.

Liquid nitrogen spilled in a closed room can kill with no warning because it evaporates and starves people of what?

Oxygen levels fall as the liquid turns into nearly 700 times its volume of gas, and nitrogen has no smell, colour or taste to warn anyone. Some labs fit sensors that sound an alarm when the air goes bad.

Clarence Dally, a glassblower working for Thomas Edison, died in 1904 after years of testing which new radiation?

X-rays were not believed to be harmful when Dally began testing the beam on his own hands. His is thought to be the first human death from exposure to them, and Edison dropped the research afterwards.

Mixing household bleach with ammonia-based cleaners is a bad idea because the pair release which toxic gas?

Chloramine vapours, not chlorine as many people assume, are what the two cleaners give off together. The same reaction happens when bleach meets urine, which also releases ammonia compounds.

Which lab machine, working on the same principle as a kitchen pressure cooker, sterilises equipment with steam?

Autoclave steam is held under pressure at about 121 °C, far hotter than boiling water in an open pan. Charles Chamberland invented the machine in 1879, two centuries after Denis Papin's steam digester.

On the 'fire diamond' label found on chemical tanks and containers, what kind of hazard does the blue section rate?

Health risk sits in the blue square on the left, scored from 0 for no real hazard up to 4 for severe. Red at the top rates how easily a material burns, and white carries codes for special hazards.

Under the worldwide GHS system for chemical labels, which signal word marks the more severe hazards?

Danger and Warning are the only two signal words the system uses, and a label carries just one of them, matching its most severe hazard. Some low-level hazards get no signal word at all.

Class D fire extinguishers, filled with special dry powder, are made for fires involving which kind of material?

Combustible metals such as magnesium, lithium and titanium fall into this class, and some of them catch fire on contact with water. The usual smothering agents are salt granules and graphite powder.

Dry ice must never be kept in a tightly sealed container because, as it warms up, it does what?

Dry ice turns straight to gas as it warms, skipping the liquid stage, so the pressure in a sealed bottle climbs until it ruptures. That can take anywhere from seconds to half an hour.

Which of these viruses is studied at biosafety level 4, the top tier, by staff in positive-pressure suits?

Ebola virus is one of several haemorrhagic fever viruses kept at the highest containment level, alongside Marburg and Lassa. Leaving such a lab means a chemical wash-down while still wearing the suit.

Alfred Nobel's younger brother Emil was among five people killed when which explosive blew up a Stockholm shed?

Nitroglycerin was being prepared in the shed at the family's Heleneborg works when it exploded in 1864. Three years later Nobel patented dynamite, a form of it that was easier and safer to handle.

A lab explosion that injured Humphry Davy led him to hire which future pioneer of electricity as a helper?

Michael Faraday was taken on at first to help with handwriting and record keeping while Davy recovered. Soon afterwards both men were hurt in a second blast involving the same unstable compound.

Which fish gives its name to the mix of sulfuric acid and hydrogen peroxide that strips residue off lab glassware?

Piranha solution earned the name by rapidly dissolving and 'consuming' almost any organic material it touches. Many institutions discourage routine use of it because the mixture is so hazardous.

On a chemical's hazard sheet, which term describes a substance that can cause birth defects in an unborn child?

Teratogen comes from a Greek word for a monster or marvel. Alcohol and the drug thalidomide are well-known examples, and the harm done depends heavily on the stage of pregnancy at exposure.

In radiation safety, the letters ALARA tell workers to keep every dose as low as reasonably what?

Achievable is the American wording, while British rules say 'practicable' instead. Either way, a risk passes the test only when cutting it further would cost out of all proportion to the benefit.

Old bottles of which once-popular anaesthetic solvent are a hazard because explosive peroxides build up inside?

Diethyl ether reacts slowly with air and light to form peroxides, which explode on contact once they dry out. Suppliers add a trace of antioxidant to the bottle to slow the build-up.

A reagent bottle marked 'lachrymator' warns that the vapour inside will quickly make a person do what?

Weep is the right word: 'lachrymator' comes from the Latin 'lacrima', a tear, and tear gas is the best-known example. Such vapours work by stimulating the nerves of the eye's tear gland.

Bomb disposal teams are often called when an old jar of which lab chemical, once a military explosive, dries out?

Picric acid was the main high explosive of most military powers before TNT replaced it, and it also served as a dye and a burn treatment. Antique first-aid kits that contain it can be hazardous too.

Which SI unit, named after a Swedish medical physicist, measures the radiation dose a person has received?

Sievert readings estimate biological risk rather than raw energy, so the same absorbed dose counts for more from some kinds of radiation than from others. Rolf Sievert was a pioneer of dose measurement.

The reagent tert-butyllithium is labelled 'pyrophoric', meaning that it does what on contact with air?

Ignites spontaneously is what the label means, from the Greek for 'fire-bearing'. In a fatal 2008 accident at UCLA, a plastic syringe of the reagent came apart and the researcher was not wearing a lab coat.

Laboratory beakers and test tubes are made of which low-expansion glass, first developed by Otto Schott in Jena?

Borosilicate glass expands only about a third as much as ordinary soda-lime glass when heated, so it shrugs off thermal shock. In the English-speaking world it became famous under the Pyrex name.

Which double-walled vacuum vessel for very cold liquids is named after the Scottish scientist who invented it?

Dewar flask designs put one vessel inside another, joined at the neck, with a vacuum in between. James Dewar refused to patent the idea, which is how it also became the household thermos.

What is the name for the lowest temperature at which a liquid gives off enough vapour to catch light from a spark?

Flash point sits just below the fire point, the temperature at which the vapour keeps burning after the spark is taken away. At the flash point, vapour forms too slowly to keep a flame going.