The first unit of the kitchen sequence: twenty seconds of handwashing, the USDA’s four steps, the temperature danger zone, safe internal temperatures, the two-hour rule, safe thawing, grease fires, burns, knives and allergens. Four tabs — study cards to learn the words, hints to hold the numbers, a quiz that asks you to reason, and a workshop where you order the steps, sort safe from unsafe, label a thermometer and judge a dish by its clock.
A thermometer standing up. The bottom end is cold. The top end is hot.
That shaded band has a name: the temperature danger zone, 40 °F to 140 °F, or 4 °C to 60 °C. Inside it, the number of bacteria can double in about twenty minutes. Food does not go bad by the clock alone — it goes bad in that range, and the time it spends there adds up.
What people get wrong
⚠️People often think…
Food that still looks and smells fine is still safe to eat.
The bacteria that make you sick do not change how food looks, smells or tastes. A dish carrying enough of them to send somebody to a hospital can look exactly like lunch.
Your nose does not count bacteria.
⚠️People often think…
The two hours start over each time the food goes back in the refrigerator.
The two hours are a running total for the whole day. Fifty minutes at lunch plus ninety minutes in the afternoon is 140 minutes, and that dish is already past the limit.
The clock adds up. It never restarts.
⚠️People often think…
Reheating food that sat out makes it safe again.
Heat changes the temperature; it cannot change the hours already spent in the zone. Some bacteria also leave behind toxins that cooking does not destroy.
Reheating moves the temperature, not the time.
⚠️People often think…
Meat is done when it is brown all the way through.
Color and temperature do not track each other. Brown meat can still be under 165 °F, and a pink piece can already be safe. The thermometer, in the thickest part, is what decides.
Color is not a temperature.
Two edges and a running clock
1Watch one
Chicken salad goes on the table at 11:00. Nobody puts it away until 1:30. Can it be served?
The room is about 70 °F.
70 °F is inside the danger zone.
11:00 to 1:30 is 2 hours 30 minutes.
The limit is two hours, total.
Past the limit. The salad is thrown out. ✓
2Do one with me
Three numbers this unit runs on, in °F.
The danger zone starts at
The danger zone ends at
Chicken is safe at
💬One sentence, then you move on
Why is a number safer to trust than a look or a smell?
3Try one
A cooked casserole sat on the counter from 9:40 until 12:05. The room was about 72 °F. Can it be served — yes or no?
I want a hint first
Put your finger on the clock. Count 9:40 to 12:05 in hours and minutes, then hold that next to the two-hour limit.
💬Last one — then you’re done here
Why does putting the casserole in the refrigerator at 12:05 not fix it?
Where this goes
Where this lives
A family cooler at a summer picnic: the potato salad comes out at noon and the lid stays open. Above 90 °F the limit drops to one hour. Or leftovers after a long shift, sitting on the stove while the house sleeps.
What this feeds
Next unit is Knife Skills. A safe room first, then a safe tool.
Name one dish in your week that waits on a counter, and say how long it waits.
One card at a time — tap “Show me” to check yourself, then Next. Start at Foundation; when those feel easy, climb.
Helpful Hints
🧭 The unit in one line
Wash your hands twenty seconds → keep raw meat away from everything else → cook to a number, not a color → get it cold inside two hours → and know, before anything burns, where the extinguisher and the fire blanket hang.
Clean · Separate · Cook · Chill. 165, 160, 145. Two hours.
🔑 The one idea
You cannot see the danger. Food with enough bacteria to make you sick looks normal, smells normal and tastes normal. So we do not guess — we use a clock, a thermometer and a rule.
⚠️ Traps to avoid
Never put water on a grease fire. Turn off the heat and smother it with a metal lid or a fire blanket.
Never thaw meat on the counter. The outside sits in the danger zone for hours before the middle thaws.
Never put ice or butter on a burn. Cool running water, at least ten minutes, then tell the teacher.
Never grab a falling knife. Step back and let it land.
Color is not doneness. Brown meat can be undercooked and pink meat can be safe — only a thermometer decides.
Wiping a board is not the same as sanitizing it, and rinsing a knife in cold water does nothing to raw chicken juice.
The two hours add up across the whole day. Putting the food away later does not restart the clock.
📐 The numbers — the chart
Food or place
°F
°C
Note
Chicken, turkey, any poultry
165
74
whole bird, pieces, ground — all of it
Leftovers, reheated
165
74
stir, then check the middle
Ground beef, pork, lamb
160
71
grinding mixes the outside in
Egg dishes
160
71
cooked until firm, not runny
Beef, pork, lamb — whole cuts
145
63
then rest three minutes
Fish
145
63
the flesh separates easily
The temperature danger zone
40–140
4–60
two hours in it, total, and no more
Refrigerator
40 or below
4
freezer 0 °F, about −18 °C
🎯 How you will be asked
“Give the safe internal temperature for chicken, for hamburger and for a steak.”
“Name the four steps the USDA teaches, and give an example of each.”
A short story from a lab — “what went wrong, and what should they have done?”
“A pan of oil catches fire. List what you do, in order.”
A dish and a clock — “can it be served? Use a temperature and a time to prove it.”
✅ Before the test, can you…
Say the four steps in order, and what each one means?
Give the danger zone in °F and in °C without looking?
Give 165, 160 and 145, and say which food goes with each?
Name the three safe ways to thaw, and the one that is never safe?
Say what PASS stands for, and point to the extinguisher and the fire blanket?
Explain the difference between cleaning and sanitizing in one sentence each?
📚 Go to the sources
These are the agencies that write the numbers on this page. They open another website and need the internet. Look for the word Español at the top of each one — all four publish in Spanish.
Look back at anything you missed — the hint that appeared is exactly what to reread tonight.
How sure did you feel?
Workshop
Work like a cook who gets inspected: walk into the lab in the right order, tell safe from unsafe, label a thermometer, then judge a dish by its temperature and its clock.
Your practice never leaves this device. There is no account and no sign-in. Your work is saved in this browser only, and you can erase it whenever you want.
Your practice record — saved on this device
This is your record of the module on screen — it stays here and goes nowhere. Independent means you got it right on the first tap; supported means you got it after the explain-and-retry, or marked ‘I had it’ on a revealed answer. Both count, and neither is a grade. If your teacher asks, copy the row or show them this screen.
Date
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Topic
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Level
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Independent
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Supported
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Hints used
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Cards studied
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Lab
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Traps met
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Explained in own words
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Confidence
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The answer key is for a teacher: it prints only from here, for the unit on screen. Print the study packet prints the study pages and a blank quiz — never the answers.