Good question!

The 2h/4h rule (also seen written as 2/4h rule, 2-hour/4-hour rule, etc.) is used for two things: cooling potentially hazardous foods, and potentially hazardous foods left out of temperature control.

Cooling: Foods are to be cooled from 60C to 20C within two hours, and from 20C to 4C within the following four hours. Of course most foods are cooked above 60C, which is the range where pathogenic bacteria don’t grow. You want to get food from 60C to 4C within the certain time frame, otherwise it just gives bacteria some good conditions to grow well (food, no other microbes to compete with, etc.). The range of 4C-60C is called the “temperature danger zone.” Foods should stay out of here as much as they can.

Food left out of temperature control is something else that many people are less stringent about, but it is also really important (think summer time bbq season). Potentially hazardous foods can be in and out of the fridge for a cumulative total of two hours (example: you take out a food item and put it back in after 5 minutes, now it has 115 minutes left. Do it again tomorrow, it now has 110 minutes, etc.). After the two hour mark up to four hours, you eat it or throw it out. Once it hits four hours, throw it. Someone used milk as good example. Milk in the fridge door goes off far faster than on a shelf. Foods on the BBQ cooked at noon should be eaten or thrown out by 4PM.

There are lots of other little details and exceptions, but this is what applies in the majority of cases. ;)

At home, I just use soap, water and a scrubber. As an additional step, I also either wipe it down with an alcohol wipe if I have any laying around, or let it sit in freshly boiled water. I’m not crazy about doing this for everything except with undercooked or raw poultry.

At work, everyone is required by law to implement a sanitising step to ensure any residual harmful microbes are destroyed… but I’d never deter anyone at home from doing this ;) I suggest properly diluted bleach (100ppm, or as per label instructions, freshly made), or quaternary ammonium compound (“quat”, also diluted to either 200ppm or as per label). Otherwise, dishwasher.

Yeah, that’s huge. Outbreaks are becoming more and more common. In Canada and USA, it’s a requirement to keep eggs in the fridge, and we just assume chickens = Salmonella, which is also why there is such stress on washing your hands thoroughly after handling raw chicken, cut chicken on a designated poultry-only cutting board, etc.

I think some countries will do a sanitising wash, some just wash with water.

In Australia, Salmonella infections have been increasing, so it’s strongly recommended to keep eggs refrigerated. It’s not written in to law, but we’re a little behind here on a few things. Also consider the differences in handling of eggs at a supermarket, at a farmer’s market, or someone selling excess eggs outside their home.

Another thing that needs to be considered: Egg shells are porous. In a supermarket, temperatures don’t fluctuate as much as it would at home or in a restaurant, so they’re not going to sweat (moisture = nice spot for bacteria to grow). In restaurants and at home, if they’re not in the fridge, eggs will be subject to sweating (think hot kitchen during the day, cool kitchen at night; flies, cockroaches, rodents, unclean human hands, etc.) I’ve seen eggs being sold out of eskies on the side of the road, and I avoid those. The Aussie sun is HOT.

Canadian living in Australia. Omnivore.

Kicker: Food technologist and health inspector. AMA.

Tl;dr: Doesn’t matter if it’s meat or veg. It goes in the fridge. Follow 2h/4h rule. Edit: Should specify certain veg are potentially hazardous as soon as you cut in to them, like leafy greens. All cooked or partially veg that should be treated like meat.

For work, I’m fairly strict in businesses because the food can go anywhere once it’s in the hands on the customer, even in restaurants or at home. You can look at your dine in customers and they all look healthy, but what if they’re not, or where do the leftovers go? Do they take it home after date night to share some with little Bobby or Grandma Jane? In business, you do what you can to keep the food as “clean” as you can.

At home and in food businesses, handwashing is ALWAYS a problem. Food handlers are always touching their faces, phones, hip towel they’ve had on all day, touching a towel they use used to wipe their hands after only rinsing hands in water in the sink, and then touching lettuce for a salad. So even at home, you can cook things to keep bacteria, but is the scoop, container, and your hands clean? Dust, pollen, flies, hairs, etc also carry microbes, and if any of them fall in to food after its been cooked, the bacteria can grow.

It also depends on the type of bacteria, too. Salmonella can infect at an extremely low dose, and Staphylococcus infects at very high doses.

I follow the 2h/4h rule for anything potentially hazardous. Of course, at home, I’m a bit more flexible, usually +/- 1h. If I make myself sick, alright, but there’s no way I’m going to make anyone else sick, so if I’m making food for others, I keep to the strict rules. I’m also generally more risk adverse because the thought of anything involuntary coming out either end makes me sick just thinking about it.

I think the amount of time a food stays out is cultural, and if you grew up with it, your gut will have gotten used to the levels of bacteria. Us westerners generally get sick drinking tap water in certain countries when the locals are fine. I used to live with a Japanese lady for a year, and she knew what I did for a living. She always left rice out all night and ate it the next day. One day, she came to me with it and said “does this smell weird?” and it was a definite yes from me. I’d never leave cooked rice out that long and feel comfortable eating it.

So yeah, Bacillus cereus or whatever bacteria present may not occur all the time, but it does happen. Imagine making large batches and serving to large numbers of unrelated people.

Another thing: Cool foods within 2h to a reasonable temperature (I say 40C is fine) before putting it in the the fridge uncovered. If you put hot food in the fridge, you run the risk of warming up the foods already in the fridge.

Wash your hands.

And use a thermometer. Make sure it’s clean before you use it.

Thanks for listening to my Ted Talk.

I’m not so up on what’s new and such, and I’ve really enjoyed a few games I’ve downloaded:

(Obligatory apology for any link or format issues. On mobile and first time posting.)

Scalak. You rotate and move blocks and pieces around to try to match up edges. Hard to explain. Kind of like the baby’s “put the square in the square hole” toy except for adults. It’s got really nice, calming music, so it’s nice to play before bed or offline on the plane.

MultiSudoku. Off-line sudoku that has five sudoku squares (?) attached together.

Word Hero. I love word games and this has been my favourite. It’s basically Boggle and after each game, it ranks the scores from everyone around the world who played the same game as you. Been playing this for years. Unfortunately online only.

Burnable Garbage Day. Earth has completely filled with rubbish, and a cleaning robot has woken up from a deep slumber to find out why the planet has become this way. Originally a Japanese game so the translations are a bit dodgy, but it’s a really fun play. I think it can be played offline. It’s been a while since I’ve played this.

Mahjong 13 Tiles. The only actual mahjong game I could find that isn’t like the old Windows tile matching game. This is the gambling version where there is no money bets, but you can play against bots. It’s been ages since I’ve played this so I can’t remember if it’s online or offline or if you can play against real people.

Dingbats. Guessing famous idioms from drawings. Can be played offline.

Quell Reflect. Moving a bubble around to capture all the gems. The puzzles get harder as you progress. Can be played offline.

Influence. You start with one cell (think Chinese checkers) and you keep spreading your influence to conquer the other players. Can be played off-line.

What the Forecast. Obnoxious, rude weather app.

Whicons. Minimalist white icon pack for Android.

BirdNET. Identifies birds by their call. I’ve used this in Canada and Australia.

Plant Net. Same thing as BirdNET but photos of plants. Also can confirm it works in Canada and Australia.

Edit: Forgot one game, Slitherlink. I set it to easy and listen to podcasts in the background to wind down at the end of the night. Each hexagon (or whichever shape you choose) has a number, and each number represents the max number of sides that can be selected. Eventually the entire board is connected via one line. You’ll have to read the description, it’s the best description I can give, albeit not a very good one.

Edit edit: This is what happens when I haven’t had my coffee yet. Kakuro is another numbers game like sudoku.