97 Fun Facts About Hygiene

Which Greek goddess, a daughter of Asclepius, personified health and cleanliness?

Hygieia, daughter of the medicine god Asclepius, personified health and cleanliness; her name is the root of the English word 'hygiene'.

The US CDC recommends scrubbing your hands with soap for at least how long?

The CDC says to scrub for at least 20 seconds, about the time it takes to hum 'Happy Birthday' twice; water temperature makes no difference, friction removes the germs.

Who introduced chlorinated-lime hand disinfection in Vienna's First Obstetrical Clinic in 1847?

Ignaz Semmelweis ordered chlorinated-lime hand washing in 1847, sharply cutting childbed-fever deaths; unable to explain why it worked, he was mocked by colleagues.

Evidence of soap-like materials being made dates back to around 2800 BC in which ancient civilisation?

Babylon: soap-like residues there date to about 2800 BC, and a Babylonian clay tablet from about 2200 BC records a recipe of water, alkali and cassia oil.

The first modern-style toothbrush, from Tang-dynasty China, used which animal's bristles?

Bristles came from hogs in Siberia and northern China because cold weather made them firmer; handles were bamboo or bone.

Where did William Addis come up with the idea for the first mass-produced toothbrush in 1780?

In prison: jailed in 1770 for rioting, Addis drilled holes in a saved meal bone and threaded in bristles, then founded his toothbrush business in 1780 after his release.

Which company introduced nylon toothbrush bristles, replacing animal hair, in 1938?

DuPont supplied the nylon for Dr. West's Miracle-Tuft, the first nylon-bristle toothbrush, which went on sale on February 24, 1938 and replaced animal bristles.

Dr. Washington Sheffield put toothpaste in a collapsible tube in 1880 after his son saw what in Paris?

His son Lucius saw painters squeezing paint from collapsible metal tubes in Paris; Sheffield then packaged his Creme Dentifrice in similar metal tubes from 1880.

What did dental floss inventor Levi Spear Parmly recommend running between teeth in 1819?

Parmly's 1819 book A Practical Guide to the Management of the Teeth advised passing waxed silk thread between the teeth, calling it the most important part of oral care.

The first modern commercial deodorant, patented in Philadelphia in 1888, was sold under what name?

Mum, patented in Philadelphia in 1888 by an unnamed inventor, was the first commercial deodorant; the trademark was given to his nurse, who chose the name.

The first commercial antiperspirant, launched in 1903, was called what?

Everdry, launched in 1903, was the first commercial antiperspirant; its aluminum chloride solution stopped sweat but irritated skin, a problem Jules Montenier's 1941 formula later solved.

The English word 'shampoo', dating to 1762, comes from a Hindi word meaning what?

Hindi champo means 'to press or knead'; when 'shampoo' entered English in 1762 it meant a head and body massage with oil, not a hair soap.

The earliest recorded use of paper for toilet hygiene, in the 6th century AD, comes from which country?

China: the scholar-official Yan Zhitui wrote of using paper this way around 589, and by 1393 the Ming court was ordering hundreds of thousands of purpose-made sheets a year.

Joseph Gayetty's 'Medicated Paper', the first commercial toilet paper in the US, launched in which year?

Gayetty launched his Medicated Paper in 1857 as flat aloe-treated sheets watermarked with his name, sold in packs of 500.

Which company popularised toilet paper on rolls when it began marketing them in 1890?

Scott Paper Company of Philadelphia began selling toilet paper on rolls in 1890; Seth Wheeler of Albany had patented the perforated roll and a dispenser in 1883.

Which pioneer of antiseptic surgery gave his name to a mouthwash developed in 1879?

Joseph Lister, the antiseptic-surgery pioneer, inspired the name of Joseph Lawrence's Listerine of 1879, first sold as a surgical antiseptic and floor cleaner before becoming an over-the-counter mouthwash in 1914.

Listerine sales exploded in the 1920s when it was sold as the cure for which then-obscure term?

Halitosis: Listerine's 1920s ads turned the obscure medical term for bad breath into a household fear; the word, from Latin halitus ('breath'), dates to 1874 and was not coined by the brand.

Global Handwashing Day is marked every year on which date?

15 October has been Global Handwashing Day since the first one in 2008, promoting washing with soap before eating and after using the toilet.

The CDC recommends alcohol-based hand sanitizer containing at least what percentage of alcohol?

Formulas of 60 to 95 percent are most effective; they kill most microbes but not spores, and they are flammable.

Which chemical did Joseph Lister introduce at the Glasgow Royal Infirmary in 1865 to sterilise wounds and tools?

Inspired by Pasteur's work on microbes, he showed in 1865 that carbolic dressings sharply cut post-surgical infection.

In 1854 John Snow traced a London cholera outbreak to a public water pump on which Soho thoroughfare?

Broad Street (now Broadwick Street): Snow's map clustered deaths round its pump and the parish removed the handle on 8 September 1854, though officials later replaced it and rejected his theory.

Joseph Bazalgette built London's main sewer system in response to which event of 1858?

The Great Stink of summer 1858, when the sewage-filled Thames reeked so badly that Parliament's curtains were soaked in chloride of lime, pushed MPs to fund Bazalgette's sewers, which helped end London's cholera epidemics.

King Camp Gillette's safety razor became dominant after which body began issuing them to soldiers?

The US Army issued Gillette safety razors to its troops in the First World War, buying millions of razors and blades in 1918 and sending servicemen home with the habit.

Leo Gerstenzang invented the mass-produced Q-tip in 1923 after watching his wife do what?

He first called them Baby Gays, then Q-tips Baby Gays; the Q stood for quality.

The word 'bidet' is French for what?

Bidet means 'pony' in French, because you straddle the fixture like a small horse; French furniture makers seem to have invented it in the late 17th or early 18th century.

Sir John Harington described a forerunner of the flush toilet in 1596 and installed one for which monarch?

Elizabeth I, Harington's godmother, had one of his water closets installed at Richmond Palace; his 1596 book was punningly titled The Metamorphosis of Ajax ('a jakes' being a privy).

Alexander Cumming's 1775 patent for what device laid the foundation of the modern flush toilet?

Cumming's 1775 patent covered the S-trap, a bend that keeps standing water in the pipe to seal out sewer gases, together with a sliding valve beneath the bowl.

Under what brand was Earle Haas's tube-within-a-tube applicator tampon sold from 1933?

Tampax: Gertrude Tenderich bought Haas's patent in 1933, at first making the tampons at home with a sewing machine, and hired nurses to give public lectures on the product.

Which slogan did Ivory soap introduce in 1891?

'It Floats!' became Ivory's slogan in 1891, trading on the air whipped into the soap mixture that let the bar bob to the surface of the bath.

Community water fluoridation to prevent tooth decay began in which year?

Grand Rapids, Michigan, became the first city to fluoridate its water on 25 January 1945, after decades of research into the 'Colorado brown stain' mottling seen where fluoride was naturally high.

The first electric toothbrush to reach the market, the Broxodent, was invented in 1954 in which country?

Switzerland: Dr. Philippe-Guy Woog designed the Broxodent there in 1954, originally for patients with limited motor skills; an American patent for a 'Motodent' had been filed back in 1937.

Which emperor built the enormous Roman baths, with library rooms, completed in 216 AD?

Caracalla's baths, opened in 216, could serve some 1,600 bathers and held two libraries, one Greek and one Latin; their vaulted halls inspired the waiting room of New York's original Penn Station.

Which 1990 self-help book by sleep researcher Peter Hauri laid out sleep-hygiene rules?

No More Sleepless Nights (1990), by Peter Hauri and Shirley Linde, brought sleep-hygiene rules to a popular audience; Hauri had first set them out for clinicians in 1977.

Florence Nightingale is credited with inventing which kind of statistical chart?

Her polar area diagrams, nicknamed coxcombs, showed that far more Crimean War soldiers died of disease than of wounds; the form is often called the Nightingale rose.

Which French and German pair of scientists are most associated with proving the germ theory of disease?

Louis Pasteur and Robert Koch: Pasteur's swan-neck flasks disproved spontaneous generation in the 1860s, and Koch's postulates and his 1882 identification of the tuberculosis bacillus tied specific germs to specific diseases.

Which Greek physician recommended a mouth rinse of salt, alum and vinegar around 400 BC?

Hippocrates, writing around 400 BC, recommended rinsing the mouth with salt, alum and vinegar, one of the earliest recorded mouthwash recipes.

Which deodorant brand did Bristol-Myers launch in 1952?

Ban Roll-On, launched by Bristol-Myers in 1952, used a rolling-ball applicator that Helen Barnett Diserens modelled on the newly popular ballpoint pen.

In 1873, which company began mass-producing aromatic toothpaste in jars, before tubes existed?

Colgate began selling its first toothpaste, an aromatic dentifrice in jars, in 1873; it switched to collapsible tubes with Ribbon Dental Cream in 1896.

Whose 1791 process for making soda ash from common salt made soap far cheaper?

Nicolas Leblanc's process, patented in 1791, turned common salt into soda ash, the alkali soap makers needed, and helped turn soap from a luxury into a mass product.

Which obstetrician urged cleanliness on lying-in wards to prevent childbed fever as early as 1773?

Charles White's 1773 Treatise on the Management of Pregnant and Lying-in Women urged cleanliness and ventilation in childbirth; Alexander Gordon (1795) and Oliver Wendell Holmes (1843) later tied childbed fever to attendants' hands.

How often should a healthy adult replace their toothbrush, according to standard advice?

About every 3 months: the American Dental Association advises a new brush every three to four months, or sooner once the bristles fray.

England's NHS advises against doing what immediately after brushing your teeth?

Rinsing with water washes away the concentrated fluoride left by toothpaste; the NHS says to spit out the excess and not rinse, and to avoid brushing straight after acidic drinks.

Alcohol-based hand sanitizers are considered ineffective in which situation?

On visibly soiled or greasy hands, sanitizer cannot reach the germs under the dirt; soap and running water are needed to physically remove it.

Sleep hygiene recommendations were first developed in the late 1970s to help people with what?

Mild to moderate insomnia: the rules were drawn up in the late 1970s as a first-line, drug-free approach, though later reviews found the evidence for individual recommendations limited and inconclusive.

What broad term covers antiseptics, disinfectants and pesticides alike?

Biocide is the umbrella term for any chemical meant to destroy or control harmful organisms, so it covers antiseptics for skin, disinfectants for surfaces and pesticides alike.

Which label means a disinfectant kills the dormant, highly resistant form of bacteria?

Sporicidal disinfectants kill bacterial spores, the hardest targets; all disinfectants are bactericidal but only some are also fungicidal, virucidal or sporicidal, so labels matter.

'Targeted hygiene' in the home borrows its risk-based approach from which food-safety system?

HACCP (Hazard Analysis and Critical Control Points), the food-industry system, inspired targeted hygiene: identify the moments and surfaces where germs spread and break the chain of infection there, rather than cleaning everything.

Which billionaire drank water made from human sewage to promote his foundation's work on sanitation?

Bill Gates sipped water from the Omni Processor, a plant that turns sewage sludge into drinking water and electricity. His foundation also set engineers the Reinvent the Toilet Challenge.

Which disposable tissue brand was first sold as a cold-cream remover rather than for blowing noses?

Kleenex was pitched for wiping off make-up until the 1930s, when adverts recast the sheets as disposable handkerchiefs and that use took over.

Mary Mallon, a New York cook with no symptoms herself, infected the families she worked for with which disease?

Typhoid fever followed Mary Mallon from kitchen to kitchen, earning her the nickname Typhoid Mary. Officials confined her on North Brother Island in New York's East River.

Why do food-safety agencies tell cooks never to wash raw chicken before cooking it?

It splashes germs around the kitchen onto clean surfaces, and Britain's food-safety agency ran a whole campaign against the habit. Campylobacter, the main culprit, can be very numerous on raw poultry.

Lice that live in children's hair cannot jump or fly, so which route accounts for most of their spread?

Head-to-head contact is by far the commonest route, since the insects can only crawl from one hair to the next. Cats and dogs play no part, and neither does dirty hair.

Which Nordic country, home to at least two million saunas, gave English the word 'sauna' itself?

Finland has about 5.5 million people, so that is roughly one sauna for every two or three residents. The Finnish Sauna Society puts the true figure as high as 3.2 million.

Which outer layer of a tooth, the hardest substance in the human body, is slowly dissolved by acids from plaque?

Enamel is 96% mineral and has no way to regenerate itself, so the body cannot replace whatever acid wears away.

Health agencies advise coughing or sneezing into which body part when no tissue is available?

Elbow or upper-sleeve sneezing keeps droplets off the hands, which go on to touch door handles, phones and other people. Looking down as you sneeze helps too.

Bacteria in dental plaque feed on which food ingredient, producing the acid behind tooth cavities?

Sugar feeds decay bacteria, which turn it into lactic acid. After each sugary snack, minerals at the tooth surface can stay dissolved for two hours.

The American Dental Association recommends brushing teeth twice a day for how long each time?

2 minutes is the mark at which many electric toothbrushes buzz or briefly cut out, a built-in timer for the standard advice.

What do dentists call dental plaque that has hardened into a deposit only professional cleaning can remove?

Tartar, or dental calculus, forms when minerals from saliva settle in plaque. Its rough surface then gives fresh plaque an ideal place to cling.

Which early gum disease, reversible with good brushing, makes gums red, swollen and quick to bleed?

Gingivitis clears up once plaque is kept off the gumline. Left alone it can progress to periodontitis, which destroys the bone that holds teeth in place.

Which part of the mouth, when coated with bacteria towards the back, is the commonest source of bad breath?

Tongue coating is the usual culprit, which is why cleaning it is among the first remedies suggested, alongside mouthwash and flossing.

Body odour usually first appears at which stage of life, when rising hormones change the make-up of sweat?

Puberty brings a surge of androgens, hormones that also make the skin oilier and start underarm hair growing.

Which skin condition, affecting most teenagers, starts when oil and dead skin cells clog hair follicles?

Acne has nothing to do with being dirty: cleanliness is not linked to it, and susceptibility is mainly inherited.

Which itchy, peeling condition between the toes is often picked up barefoot in public showers and locker rooms?

Athlete's foot affects about 15% of people worldwide, sporty or not. Tight shoes and socks worn for more than a day both raise the risk.

Ringworm, the itchy ring-shaped skin rash common in children, is caused by which kind of organism?

Fungus, not a worm: about 40 types can cause ringworm, which spreads through shared showers, contact sports and contact with animals.

Antiperspirants block sweat ducts with gel plugs formed by compounds of which metal?

Aluminium salts react with sweat to form temporary gel plugs in the ducts, which wear away as the skin sheds. A plain deodorant only tackles the smell.

Which glands, found mainly in the armpits and groin, make the oily secretion that bacteria turn into body odour?

Apocrine glands release a cloudy, oily fluid that has no smell at all until microbes on the skin break it down.

Which oily substance, made by glands that open into hair follicles, lubricates the skin and hair?

Sebum is made most heavily on the face and scalp, which is why those turn greasy first. The palms and soles have no such glands at all.

Which intensely itchy skin infestation is caused by a tiny mite that burrows into the skin to lay eggs?

Scabies, sometimes called the seven-year itch, is contagious and usually passes on through prolonged skin-to-skin contact with someone who has it.

What name is given to the eggs of head lice, found attached to hair shafts close to the scalp?

Nits gave English the word 'nitpicking', from the slow job of removing each one from another person's hair by hand.

Which flaky scalp condition affects about half of all adults, more often men than women?

Dandruff is thought to arise when scalp skin cells mature and shed in two to seven days rather than the usual month or so.

Which contagious skin infection of young children forms honey-coloured scabs around the nose and mouth?

Impetigo is caused by bacteria, usually staph or strep, getting into the top layer of skin, and it is most common between the ages of two and five.

Which common nervous habit is known to doctors as onychophagia?

Nail biting can damage the fingers and cuticles and turn the hands into a route for infection.

What is the medical name for earwax, the secretion that traps dust before it can reach the eardrum?

Cerumen comes in two inherited types, wet and dry, and a single DNA letter change in one gene decides which a person makes.

Which contagious eye infection, known as pink eye, often spreads when children rub their eyes with unwashed hands?

Conjunctivitis inflames the thin, clear layer that covers the white of the eye and lines the eyelid. Good hygiene is the most effective way to prevent it.

Contact lenses should never be washed in which liquid, home to the sight-threatening microbe Acanthamoeba?

Tap water can carry Acanthamoeba, which survives in the gap between lens and eye. Bathing or swimming in lenses carries the same risk.

Which antibiotic-resistant 'superbug' spreads in gyms and locker rooms through skin contact and shared towels?

MRSA is a group of staph strains that shrug off a whole family of antibiotics. Sports teams are a high-risk group, so showering after exercise and not sharing razors are advised.

The 'hygiene hypothesis' suggests that very clean, infection-free childhoods raise the risk of which conditions?

Allergies such as hay fever and asthma rose through the 20th century, and David Strachan proposed in 1989 that fewer early infections might explain why.

Which highly contagious stomach bug, nicknamed the winter vomiting bug, often sweeps through cruise ships?

Norovirus lacks the fatty outer envelope that alcohol attacks, so hand gels tend to fail against it and soap and water work better.

Which intestinal parasite, once widespread in the southern United States, gets in through the skin of bare feet?

Hookworm larvae hatch in soil fouled by human waste, and heavy infections can cause anaemia. John D. Rockefeller gave $1 million in 1909 to fight it.

Which disease, spread by body lice in crowded and filthy conditions, was once known as jail fever?

Typhus tends to follow wars and disasters, when crowding lets lice thrive. In old English jails it reportedly killed more inmates than the public executioners did.

Which Dutch microscope maker first described bacteria after examining plaque scraped from his own teeth?

Leeuwenhoek told the Royal Society in 1683 about the tiny 'animalcules' he saw, and found far more in two old men who had never cleaned their teeth.

Before germ theory took over, doctors blamed cholera and plague on which noxious 'bad air' from rotting matter?

Miasma thinking gave malaria its name, from the medieval Italian for 'bad air', and held on until germ theory displaced it after 1880.

Which chemical reaction between fats and a strong alkali such as lye is used to make soap?

Saponification takes its name from 'sapo', the Latin for soap, and the reaction releases glycerol alongside the soap itself.

Which birch-derived sweetener, common in chewing gum, is thought to curb the mouth bacteria behind cavities?

Xylitol occurs naturally in plums, strawberries and cauliflower, yet it is poisonous to dogs, so gum containing it should be kept well away from pets.

Which teeth-cleaning twig, cut from the Salvadora persica tree, is recommended in Islamic tradition?

Miswak use is frequently advocated in the hadith, the traditions about the life of the Prophet Muhammad, who is said to have used one regularly.

Which steam bathhouse of the Islamic world, modelled on Roman baths, do Westerners often call a Turkish bath?

Hammam layouts kept the Roman sequence of undressing room, cold room, warm room and hot room, with furnaces sending hot air under the floor.

Which Islamic ritual washing of the hands, mouth, face, arms and feet is performed before prayer?

Wudu follows a set order that ends with the feet, and where no water can be found the Quran allows clean earth to be used instead.

Which Japanese word names hot-spring baths where guests must wash thoroughly before stepping into the water?

Onsen water comes from geothermally heated springs, of which Japan has about 25,000. The same wash-first rule applies at a sento, the neighbourhood public bathhouse.

Which antibacterial ingredient, once found in most liquid soaps, did the US FDA rule out of consumer washes?

Triclosan was among 19 ingredients the FDA struck out in 2016, having seen no evidence that such washes beat plain soap and water.

Which eye infection, spread by flies and personal contact, is the world's leading infectious cause of blindness?

Trachoma is caused by the bacterium Chlamydia trachomatis. Repeated infections scar the eyelid until it turns inward and the lashes scratch the eye.

Which parasitic disease, nearly eradicated by a Carter Center campaign, is prevented by filtering drinking water?

Guinea worm struck an estimated 3.5 million people a year in 1986. Cloth and pipe filters strain out the tiny water fleas that carry its larvae.

Which curved metal tool did ancient Greek and Roman bathers use to scrape oil, sweat and dirt from the skin?

Strigil scraping followed a rub-down with oil, and the tools were used mainly by men who trained and competed in sport. Many have been found in tombs beside a bottle of oil.

Which Indus Valley city in Pakistan holds the Great Bath, called the earliest public water tank of the ancient world?

Mohenjo-daro's builders sealed the tank with finely fitted bricks, gypsum plaster and a thick layer of bitumen to keep it watertight.

Which English reformer's best-selling report on working-class squalor led to a landmark Public Health Act?

Edwin Chadwick researched and published the 1842 report at his own expense, and it became the Stationery Office's best-selling publication to date.

Which Indian-born entrepreneur opened 'shampooing' vapour baths in Brighton and became shampooing surgeon to George IV?

Sake Dean Mahomed had already opened the Hindoostane Coffee House in London in 1810, the first Indian restaurant in England.

Which painful condition crippled First World War soldiers whose boots stayed cold and wet for days?

Trench foot was first described during Napoleon's retreat from Russia in 1812. Changing into dry socks two or three times a day helps to treat it.

Which bacterium, a well-known cause of food poisoning, is the classic hazard of raw or undercooked eggs?

Salmonella is named after the American veterinary surgeon Daniel Elmer Salmon, and it spreads through contaminated meat, eggs, water or milk.