8 ms·

Most flights I've been on are serving water in cups from bottled water the attendants are opening as they go.

pc86 9y ago
From the second paragraph of the article, emphasis mine: "Flight attendants will not drink hot water on the plane." I've only ever seen bottled water for cold drinks as well, but I seriously doubt they're boiling bottles of Desani up front.
mattkrause 9y ago
Also isn't the water....boiled for coffee and tea? Perhaps not enough to totally sterilize it, but it must help some.
- rdoherty 9y ago
  I'm 99% sure that any boiling will kill nearly all germs in water. I don't have facts on hand, but I do remember that once you get above ~160F, nearly all germs are dead. So boiling water will definitely kill everything.
  - chc 9y ago
    According to the CDC, at elevations above 6,500 feet, water needs to be boiled for three minutes to kill E. coli.
    - Bartweiss 9y ago
      That's a pressure issue, though - low air pressure drops boiling temperature, so your water doesn't actually get as hot. Most commercial aircraft are pressurized to around 11psi, which is an elevation of ~3,500 feet.
  - falsedan 9y ago
    It will kill the pathogens which cause vomiting and diarrhea: the article mentions e. coli, which the CDC[0] recommend 1 minute at boiling temperature to deactivate. I'd skip that and stop as soon as the water boiled. Note that sterilization requires higher temperatures for longer periods, but it's not required for food products consumed by the general public. Some bacteria may survive the boiling process, but your stomach acid + immune system will destroy them. [0]: https://www.cdc.gov/healthywater/drinking/private/wells/disease/e_coli.html https://www.cdc.gov/healthywater/drinking/private/wells/dise...
    - rdoherty 9y ago
      Good point! That's why posting on HN is so great, even if you're 99.9% correct, someone will always reply to tell you precisely how you are 0.1% wrong . Thanks for the link, I tried to find official sources online and had trouble.
      - falsedan 9y ago
        To be clear, I think your original comment is just fabulous and you're 100% right. I'm just curious since I know that controlling the level of E. coli contamination in milk is important from first-hand work on dairy farms, plus I know that pasteurization heats (not boils) the milk, and not for the ridiculous durations I see when searching online for "making water safe to drink".
        mattkrause 9y ago
        Also, the relevant factor is not just temperature--it's a combination of time and temperature. For milk, you can do 1-2 seconds at 135C (UHT), 15 sec at 72C (HTST), or something like 20 min at 60C.
  - Symbiote 9y ago
    Boiling point reduces as pressure reduces. Cruising altitude on a plane is roughly equivalent to air pressure at 1800-2400m, so using [1] that means water boils at around 93°C. (If I had any familiarity with Fahrenheit, I wouldn't have bothered looking this up. 160°F = 70°C, and even on Everest water boils at a higher temperature.) [1] http://docs.engineeringtoolbox.com/documents/1344/boiling_point_water_elevation_meter.png http://docs.engineeringtoolbox.com/documents/1344/boiling_po...
  - Jedd 9y ago
    > I'm 99% sure that any boiling will kill nearly all germs in water. I don't have facts on hand, but I do remember that once you get above ~160F, nearly all germs are dead. So boiling water will definitely kill everything. Occasionally I find out that something that I thought / hoped / believed to be the case ... wasn't. Killing 'nearly all germs' is good, but not really what you need when you may get sick or die from the kinds of germs that don't fit the 'nearly all' category. Cryptosporidium and giardia (two things that Sydney residents became overly familiar with before our Olympic hosting) require a few minutes of rolling boil to kill. And the definition of 'rolling boil' becomes more onerous as you increase your altitude.
  - dragonwriter 9y ago
    > I'm 99% sure that any boiling will kill nearly all germs in water. CDC says a full minute of boiling (3 minutes for elevations greater than 6,500ft) to deal with (the problem strain of) E. coli in well water. Momentary boiling is not sufficient for safety. https://www.cdc.gov/healthywater/drinking/private/wells/disease/e_coli.html https://www.cdc.gov/healthywater/drinking/private/wells/dise...
- throwaway7645 9y ago
  I think to kill all bacteria you need to boil for several minutes. A typical tea kettle turns off immediately after reaching the boiling point. Coffee is a similar story I guess.
  - mattkrause 9y ago
    Right...to actually sterilize something, you have to hold it well above boiling. Autoclaves run at high pressure so they can get liquids up to 121C. However, you don't need sterile food; you just need to ensure that there are sufficiently few bacteria that your body can deal with the rest. I would suspect boiling water (to make the coffee) and holding it hot (for serving) helps quite a bit with this, but I was wondering if anyone had some actual numbers.
  - Bartweiss 9y ago
    I guess the question is exactly what's in the water. Sterilizing river water calls for one minute at a rolling boil, which you won't get from a kettle. But something like beef, with a much more restricted threat, can be done down around 160F, and bringing your kettle to a boil should easily get you a few minutes above that line. Not all tea brewings will, but I'm guessing "boil it and throw in tea" is more common on airplanes than a delicate, 165F green tea production. So... it'd be nice to hear from a microbiologist about the specifics on this one. Regulators seem concerned, but that's about drinking it as tap water, which I wouldn't do.
Afton 9y ago
That's the point of the article. Drinking water is from bottled water. Hot beverages are from the 'tap' water, and the requirements on the tap water are not as strict as the drinking water. I assume that this is a just alarmist journalism, since water for tea/coffee is heated to boiling, and all the taps in the bathrooms say some version of 'non-potable'.
- Jedd 9y ago
  > I assume that this is a just alarmist journalism, since water for tea/coffee is heated to boiling ... Boiling at elevation is different to boiling at sea level. To kill Cryptosporidium (etc) you need a rolling boil for 1 minute (no one does this) ... and that's at sea level. At > 2km up you need to run that for > 3 minutes (and absolutely no one does that). And all this is before I even get started on the woefully uncivilised idea of using 100C water for green tea.
  - splawn 9y ago
    Boiling time is a function of air pressure, not strictly elevation. Of course if the airplanes you fly on are not pressurized then you are correct.
    - Jedd 9y ago
      You're absolutely correct. I should have been clearer. When I mentioned the >2km 'elevation' I meant in an airplane, which typically cruises around 10km ... but are pressurised, as you note. Unfortunately they're pressured to be around 2.4km (effective). Some newer planes will pressurise to around 1.8km but these are uncommon. In any case, water boils at '2.4km effective' at around 92C ... and therein lies the problem.

pc86 9y ago

From the second paragraph of the article, emphasis mine: "Flight attendants will not drink hot water on the plane." I've only ever seen bottled water for cold drinks as well, but I seriously doubt they're boiling bottles of Desani up front.

mattkrause 9y ago

Also isn't the water....boiled for coffee and tea? Perhaps not enough to totally sterilize it, but it must help some.

rdoherty 9y ago
I'm 99% sure that any boiling will kill nearly all germs in water. I don't have facts on hand, but I do remember that once you get above ~160F, nearly all germs are dead. So boiling water will definitely kill everything.
- chc 9y ago
  According to the CDC, at elevations above 6,500 feet, water needs to be boiled for three minutes to kill E. coli.
  - Bartweiss 9y ago
    That's a pressure issue, though - low air pressure drops boiling temperature, so your water doesn't actually get as hot. Most commercial aircraft are pressurized to around 11psi, which is an elevation of ~3,500 feet.
- falsedan 9y ago
  It will kill the pathogens which cause vomiting and diarrhea: the article mentions e. coli, which the CDC[0] recommend 1 minute at boiling temperature to deactivate. I'd skip that and stop as soon as the water boiled. Note that sterilization requires higher temperatures for longer periods, but it's not required for food products consumed by the general public. Some bacteria may survive the boiling process, but your stomach acid + immune system will destroy them. [0]: https://www.cdc.gov/healthywater/drinking/private/wells/disease/e_coli.html https://www.cdc.gov/healthywater/drinking/private/wells/dise...
  - rdoherty 9y ago
    Good point! That's why posting on HN is so great, even if you're 99.9% correct, someone will always reply to tell you precisely how you are 0.1% wrong . Thanks for the link, I tried to find official sources online and had trouble.
    - falsedan 9y ago
      To be clear, I think your original comment is just fabulous and you're 100% right. I'm just curious since I know that controlling the level of E. coli contamination in milk is important from first-hand work on dairy farms, plus I know that pasteurization heats (not boils) the milk, and not for the ridiculous durations I see when searching online for "making water safe to drink".
      - mattkrause 9y ago
        Also, the relevant factor is not just temperature--it's a combination of time and temperature. For milk, you can do 1-2 seconds at 135C (UHT), 15 sec at 72C (HTST), or something like 20 min at 60C.
- Symbiote 9y ago
  Boiling point reduces as pressure reduces. Cruising altitude on a plane is roughly equivalent to air pressure at 1800-2400m, so using [1] that means water boils at around 93°C. (If I had any familiarity with Fahrenheit, I wouldn't have bothered looking this up. 160°F = 70°C, and even on Everest water boils at a higher temperature.) [1] http://docs.engineeringtoolbox.com/documents/1344/boiling_point_water_elevation_meter.png http://docs.engineeringtoolbox.com/documents/1344/boiling_po...
- Jedd 9y ago
  > I'm 99% sure that any boiling will kill nearly all germs in water. I don't have facts on hand, but I do remember that once you get above ~160F, nearly all germs are dead. So boiling water will definitely kill everything. Occasionally I find out that something that I thought / hoped / believed to be the case ... wasn't. Killing 'nearly all germs' is good, but not really what you need when you may get sick or die from the kinds of germs that don't fit the 'nearly all' category. Cryptosporidium and giardia (two things that Sydney residents became overly familiar with before our Olympic hosting) require a few minutes of rolling boil to kill. And the definition of 'rolling boil' becomes more onerous as you increase your altitude.
- dragonwriter 9y ago
  > I'm 99% sure that any boiling will kill nearly all germs in water. CDC says a full minute of boiling (3 minutes for elevations greater than 6,500ft) to deal with (the problem strain of) E. coli in well water. Momentary boiling is not sufficient for safety. https://www.cdc.gov/healthywater/drinking/private/wells/disease/e_coli.html https://www.cdc.gov/healthywater/drinking/private/wells/dise...
throwaway7645 9y ago
I think to kill all bacteria you need to boil for several minutes. A typical tea kettle turns off immediately after reaching the boiling point. Coffee is a similar story I guess.
- mattkrause 9y ago
  Right...to actually sterilize something, you have to hold it well above boiling. Autoclaves run at high pressure so they can get liquids up to 121C. However, you don't need sterile food; you just need to ensure that there are sufficiently few bacteria that your body can deal with the rest. I would suspect boiling water (to make the coffee) and holding it hot (for serving) helps quite a bit with this, but I was wondering if anyone had some actual numbers.
- Bartweiss 9y ago
  I guess the question is exactly what's in the water. Sterilizing river water calls for one minute at a rolling boil, which you won't get from a kettle. But something like beef, with a much more restricted threat, can be done down around 160F, and bringing your kettle to a boil should easily get you a few minutes above that line. Not all tea brewings will, but I'm guessing "boil it and throw in tea" is more common on airplanes than a delicate, 165F green tea production. So... it'd be nice to hear from a microbiologist about the specifics on this one. Regulators seem concerned, but that's about drinking it as tap water, which I wouldn't do.

Afton 9y ago

That's the point of the article. Drinking water is from bottled water. Hot beverages are from the 'tap' water, and the requirements on the tap water are not as strict as the drinking water. I assume that this is a just alarmist journalism, since water for tea/coffee is heated to boiling, and all the taps in the bathrooms say some version of 'non-potable'.

Jedd 9y ago
> I assume that this is a just alarmist journalism, since water for tea/coffee is heated to boiling ... Boiling at elevation is different to boiling at sea level. To kill Cryptosporidium (etc) you need a rolling boil for 1 minute (no one does this) ... and that's at sea level. At > 2km up you need to run that for > 3 minutes (and absolutely no one does that). And all this is before I even get started on the woefully uncivilised idea of using 100C water for green tea.
- splawn 9y ago
  Boiling time is a function of air pressure, not strictly elevation. Of course if the airplanes you fly on are not pressurized then you are correct.
  - Jedd 9y ago
    You're absolutely correct. I should have been clearer. When I mentioned the >2km 'elevation' I meant in an airplane, which typically cruises around 10km ... but are pressurised, as you note. Unfortunately they're pressured to be around 2.4km (effective). Some newer planes will pressurise to around 1.8km but these are uncommon. In any case, water boils at '2.4km effective' at around 92C ... and therein lies the problem.