59 Fun Facts About Food Safety

Food-safety agencies define the bacterial 'danger zone' as roughly what temperature range?

4 to 60 °C (40 to 140 °F) is where germs multiply quickest, which is why big batches of leftovers go into shallow containers so they cool through it fast.

Under US guidance, perishable food left out at room temperature for more than how many hours should be thrown out?

Two hours is the limit, but on a day above 32 °C (90 °F), like a summer picnic or inside a hot car, perishables should be refrigerated within one hour.

After a power cut, what does US guidance say shows thawing freezer food is safe to refreeze?

It still has ice crystals, or sits at 4 °C (40 °F) or below, so it can be refrozen, but looks, smell and taste cannot tell you whether thawed food is safe.

Why does US food-safety guidance say to skip rinsing raw chicken?

It splashes germs onto nearby surfaces, so a rinse meant to clean the chicken raises the risk instead, while cooking it to a safe internal temperature kills the germs.

Why must ground beef reach 160 °F, when a steak is safe at 145 °F?

Grinding spreads surface germs inside, while bacteria on an intact steak mostly stay on the outside, and US inspectors treat blade-tenderized steaks as a risk for the same reason.

Where should the tip of a meat thermometer probe go?

The thickest part, not touching bone, gives the true reading, and a thermometer beats judging by eye, since ground beef can look brown and done before it is safely cooked.

WHO estimates contaminated food made roughly what share of the world's people ill in 2021?

1 in 9 people, some 866 million, fell ill from contaminated food in 2021, and the lost productivity alone cost an estimated US$310 billion.

The CDC's 2011 estimate put yearly foodborne illnesses in the US at roughly how many?

48 million is about 1 in 6 Americans a year, yet only about 9.4 million of those cases could be pinned on 31 known pathogens, and unspecified agents account for the rest.

Norovirus causes roughly what share of US foodborne illnesses traced to a known pathogen?

About 58% of those illnesses are norovirus, and outbreaks most often start when an infected food worker handles ready-to-eat food during preparation.

Norovirus takes its name from an outbreak in 1968 at an elementary school in which Ohio town?

Norwalk's outbreak samples were saved, and in 1972 Albert Kapikian finally spotted the tiny virus in them using an electron microscope.

Why do alcohol-based hand sanitisers tend not to work against norovirus?

The virus has no lipid envelope for alcohol to break apart, which is why handwashing with soap and water beats sanitiser gel during norovirus outbreaks.

Which two categories of food are most often implicated in norovirus outbreaks?

Shellfish and salad ingredients often reach the plate uncooked, so no heating step kills the virus before it is eaten.

In Rutgers' 2016 test of the five-second rule, which dropped food picked up the most bacteria?

Watermelon, the wettest food tested, picked up the most, and some bacteria crossed over in under a second, disproving the five-second rule.

A 2011 E. coli outbreak in Germany that killed dozens was traced to which food?

Sprouts carried the strain, and unusually, 88% of patients who developed the kidney-damaging haemolytic-uraemic syndrome were adults rather than young children.

Which pets did the US ban from sale below four inches long in 1975, to curb Salmonella in children?

Turtles with shells under four inches were targeted because small children put them in their mouths, and the ban cut turtle-linked Salmonella cases among children.

Which food spread Salmonella to 714 people in 46 US states in 2008–09, killing nine?

Peanut butter and paste from one company went into so many other foods, from cookies to ice cream, that the recall covered thousands of products.

Why must eggs be refrigerated in the US but not in much of Europe?

US producers wash them, eroding the cuticle, a natural barrier on the shell, which is why EU rules ban washing Class A eggs to keep bacteria from getting inside.

Which cattle disease led the EU to ban exports of British beef in 1996?

Mad cow disease had just been linked to new cases of Creutzfeldt-Jakob disease, a fatal human brain illness, so all British beef exports were halted.

Pregnant women are advised to avoid soft cheeses such as Brie and feta because of which bacterium?

Listeria can cross the placenta, so an infection during pregnancy can cause miscarriage or stillbirth.

Raw poultry is a major source of which bacterium, one of the most common causes of gastroenteritis worldwide?

Campylobacter lives in chickens' guts without making the birds ill, which is why so much raw poultry carries it.

Which paralysing nerve disorder is most commonly triggered by a bacterial infection caught from undercooked chicken?

Guillain-Barré syndrome can follow because antibodies made against the bacterium's surface sugars also latch onto matching sugars on nerve cells.

The 1992-93 E. coli outbreak that killed four children was traced to undercooked beef patties from which chain?

Jack in the Box's outbreak pushed US regulators to declare E. coli O157:H7 an adulterant in raw ground beef, so contaminated meat could be pulled from sale.

Why can cattle carry E. coli O157:H7 without falling ill themselves?

They lack the toxin's receptor, so healthy-looking cattle act as a reservoir, and beef or fresh produce touched by their manure can carry the strain.

Which fish does FDA advice for pregnant women list as a 'choice to avoid' for high mercury?

Swordfish, like other large predatory fish, carries high levels of methylmercury, which can cause intellectual disability in young children.

Honey should not be fed to children under what age because it can contain botulism spores?

12 months is the advised cut-off, because swallowed spores can germinate in a younger child's immature gut and release toxin, which older children's gut defences prevent.

Foodborne botulism has most often resulted from home-canned foods with what characteristic?

Low acid content lets surviving spores grow, and since the spores outlast boiling, commercial canning uses much higher temperatures to kill them.

The word 'botulism' comes from the Latin word for what?

Sausage is the root because the illness was first traced to tainted sausages, and 'sausage poisoning' was an old German name for it.

'Fried rice syndrome' is the nickname for poisoning by which spore-forming bacterium?

Bacillus cereus contaminates starchy foods such as rice and pasta, and leaving them unrefrigerated after cooking lets it build up its vomiting toxin, cereulide.

Which cooking method do food scientists warn can leave red kidney beans' natural toxin intact?

Slow cooking often stays below about 80 °C (176 °F), too cool to destroy the beans' lectin, while a proper boil breaks it down.

Aflatoxins, which contaminate crops such as maize, are produced by which type of organism?

Moulds such as Aspergillus produce them, and in children, exposure to aflatoxins has been linked to stunted growth.

Aflatoxin was discovered after a mysterious 1960 outbreak in England among which animals?

Turkeys, about 100,000 of them, died in England after eating contaminated feed, and tracing what had killed them uncovered aflatoxin.

What happens to the toxin behind ciguatera poisoning when the reef fish is cooked?

It stays just as dangerous, and a toxic fish tastes and smells normal, so the only real protection is avoiding high-risk reef fish such as barracuda.

Trichinosis, often caught from undercooked pork or wild game, is caused by what kind of organism?

A roundworm's larvae hide in muscle, and some species in bears and other wild carnivores survive freezing for years, so only thorough cooking makes the meat safe.

HACCP was developed in the early 1960s by Pillsbury, the US Army and which agency?

NASA needed food that wouldn't make astronauts ill, but testing finished batches used up almost all of it, so the team switched to controlling each production step instead.

Besides meat and seafood, which US drink must be produced under a mandatory HACCP plan?

Juice makers must cut the most resistant harmful microbe at least 100,000-fold, a rule brought in after outbreaks from contaminated juice, including one that killed a child.

The Codex Alimentarius, the international food code founded in 1963, is published by the WHO and which other organisation?

The FAO publishes it with the WHO, and because WTO trade rules reference its standards, countries wanting stricter food rules may have to justify them scientifically.

In Bangladesh, which spice has been adulterated with lead chromate?

Turmeric was polished with the yellow pigment because buyers wanted vividly yellow curries, which exposed the Bangladeshi children who ate it to lead.

Which 1906 novel about Chicago's meatpacking plants prompted the Pure Food and Drug Act?

The Jungle was meant to expose workers' misery, but Sinclair said he 'aimed at the public's heart, and by accident I hit it in the stomach'.

Which US president signed the Pure Food and Drug Act into law in June 1906?

Theodore Roosevelt signed it the same day as the Meat Inspection Act, capping a long campaign by government chemist Harvey Wiley, the law's chief champion.

Which sitcom popularised 'double-dipping', dunking an already bitten chip back into the shared dip?

Seinfeld had George Costanza confronted at a wake for doing it, and Clemson food scientists later found bitten chips really do carry mouth bacteria into dip, salsa picking up the most at first.

Meat, poultry and processed egg products in the US are inspected by an arm of which department?

Agriculture's inspectors examine livestock before slaughter to keep diseased animals out, then check carcasses afterwards for disease that was not visible beforehand.

How does US food-safety guidance say to wash fresh fruit and vegetables at home?

Under plain running water is enough, and US guidance says to rinse even melons whose rind you won't eat and to scrub firm produce with a clean brush.

Harvey Wiley's 'Poison Squad' volunteers ate meals laced with what, to test the effects on health?

Food preservatives such as borax and formaldehyde went into their meals, and the headlines helped build public support for the 1906 Pure Food and Drug Act.

High-temperature short-time (HTST) milk pasteurisation heats milk to about 72 °C for how long?

15 seconds at about 72 °C is calibrated to kill Coxiella burnetii, the most heat-resistant disease germ found in raw milk.

What mainly lets unopened long-life milk sold in cartons keep for months without refrigeration?

Brief sterilising heat, far above boiling for a few seconds, kills even bacterial spores, and sterile cartons then keep new germs out.

Which French confectioner pioneered preserving food by sealing it in glass bottles and heating them?

Nicolas Appert never truly understood why his method worked, since bacteriology didn't yet exist, and in 1810 Peter Durand patented the idea for tin cans.

After a 1915 typhoid outbreak, how did New York stop 'Typhoid Mary' Mallon from spreading the disease for good?

Isolating her on an island, North Brother Island, lasted until her death in 1938, after she broke her 1910 release pledge by taking kitchen work as 'Mary Brown'.

How long does US food-safety guidance say to scrub your hands with soap?

20 seconds is the minimum, and US guidance says to wash before, during and after preparing food and after handling raw meat or poultry.

Which doctor showed in 1847 that handwashing slashed deaths on a Vienna maternity ward?

Ignaz Semmelweis cut deaths sharply by having doctors wash with chlorinated lime after autopsies, yet colleagues rejected his idea until germ theory explained it.

Global Handwashing Day began in 2008, which the UN had declared an International Year of what?

Sanitation got its own UN year to push a neglected cause, since progress in getting people basic sanitation had lagged badly.

Which instruction opens the WHO's Five Keys to Safer Food?

Keep clean comes first, starting with washing your hands before handling food and often while preparing it.

Which allergen in a sandwich caused the death that led to the UK's 'Natasha's Law'?

Sesame was baked into the baguette's dough but missing from its label, so the law now makes food packed where it is sold carry a label listing everything in it.

Which power over most foods did the 2011 Food Safety Modernization Act give the FDA for the first time?

Ordering recalls was new, since before 2011 the FDA could only request them for most foods, and the law also shifted its focus from reacting to outbreaks to preventing them.

Which food is the only one US federal law requires to carry an expiration date?

Infant formula must carry a 'use by' date backed by tests showing it still holds the nutrients on its label, because formula stored too long can lose nutritional value.

Which independent government body polices hygiene in England, Wales and Northern Ireland?

The Food Standards Agency was created in 2000 in the wake of deadly food-poisoning outbreaks, and it is governed by an independent board rather than by ministers.

On UK food labels, what does a 'best before' date mainly tell you?

When quality may start to drop: food is usually still safe after its best before date, unlike a use-by date, which marks when food is no longer safe to eat.

In China's 2008 milk scandal, which chemical was added to watered-down milk to fake a higher protein reading?

Melamine let watered-down milk pass nutrition tests, but it caused kidney stones, and almost 300,000 babies fell ill.

Even without eggs, which ingredient makes raw cookie dough risky to eat, US food-safety officials warn?

The flour is a raw food made from grain grown outdoors, so it can carry germs such as E. coli until baking or heat treatment kills them.

A CDC study found US outbreaks from unpasteurised dairy had a far higher rate of what than pasteurised dairy outbreaks?

Hospitalizations ran far higher, which the study's CDC authors called consistent with more bacterial causes and a larger share of sick children.