[PSA]. 保温杯十年没换 台男疑重金属中毒一年后身亡

jumpthepig

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I use this 304 stainless steel wont rust Thermos Mugs


This one has Chinese Standard (GB) certification… Hope it was really tested as claimed by the manufacturer.

But there’s also grading systems created by:
  • British Standards (BS)
  • International Organization for Standardization (ISO)
  • Japanese Industrial Standards (JIS)
  • European Standard (EN)
  • German Standard (DIN)
  • Chinese Standard (GB)
 

Whimsica

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Safest is still one-time disposable plastic/ styrofoam.

Esp in SG where we incinerate wastes.
 

jeff79

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I use this 304 stainless steel wont rust Thermos Mugs
Still prefer ceramic cups

Hate this kind of stainless steel mug where there is a gap between the stainless steel and plastic. Very difficult to clean the gap.
 

Squaredot

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Stainless coating?? Simi lai eh... I though stainless steel through and through is the same material?
I guess some brands cut cost, so it's not a piece of stainless steel but is a layer of stainless steel coating on some material?

Just like ceramic (coated) water tumbler, I believe it's not full ceramic or else the tumbler will be damn heavy when filled with water.
 

BlackWing1977

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I guess some brands cut cost, so it's not a piece of stainless steel but is a layer of stainless steel coating on some material?

Just like ceramic (coated) water tumbler, I believe it's not full ceramic or else the tumbler will be damn heavy when filled with water.
I only see this kind of layered stainless construction on high end cookware like 3-ply stainless steel or 5-ply stainless steel... it is to improve heat distribution and retention, they normally add a copper layer in between...

Or else only found on knives like 2 layer of stainless steel over a harder steel core.
 

tessss

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I guess some brands cut cost, so it's not a piece of stainless steel but is a layer of stainless steel coating on some material?

Just like ceramic (coated) water tumbler, I believe it's not full ceramic or else the tumbler will be damn heavy when filled with water.
even the japanese elephant brand Zojirushi bottle i see that is sold in SG are made in different countries.

those made in JP price is double of those made in vietnam or china.
wonder if quality and material used is same

maybe can ask Steven Chia to investigate in an episode
 

harbinger255

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Stainless steel has simi protective layer??

Stainless steel is a composite metal. Stainless steel composition varies by grade, but all stainless steels contain at least 10.5% chromium, which is essential for their corrosion resistance. Common alloying elements include nickel, molybdenum, manganese, and silicon. The most common grade, 304, typically contains 18% chromium and 8% nickel, while 316 adds 2% molybdenum for increased corrosion resistance

304 Stainless Steel:
18% Chromium, 8% Nickel, 0.08% Carbon, 2% Manganese, 0.75% Silicon, 0.045% Phosphorus, 0.03% Sulfur

316 Stainless Steel:
16-18% Chromium, 10-14% Nickel, 2-3% Molybdenum, up to 2% Manganese, up to 0.75% Silicon, up to 0.10% Nitrogen, up to 0.08% Carbon, up to 0.045% Phosphorus, up to 0.03% Sulfur

310 Stainless Steel:
23-27% Chromium, 0-1% Manganese, 0.01-0.08% Carbon

https://www.unifiedalloys.com/blog/stainless-grades-families
Chromium oxide layer lah.... that's what give SS it's anti corrosion properties....

SS304 will be general use but susceptible to chorine pitting... that's why not suitable for use near seawater... thus 316 has molybdenum alloyed in to increase protection against pitting... if you are gonna use submerged in seawater, then you prolly have to go for high nickel superalloys for critical functions
 

jumpthepig

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Chromium oxide layer lah.... that's what give SS it's anti corrosion properties....

SS304 will be general use but susceptible to chorine pitting... that's why not suitable for use near seawater... thus 316 has molybdenum alloyed in to increase protection against pitting... if you are gonna use submerged in seawater, then you prolly have to go for high nickel superalloys for critical functions

The statement is generally true.
Pitting is caused by a reaction between chlorine in salt and the stainless steel, particularly when salt is added to cold water. Pitting, which appears as small pockmarks on the surface of stainless steel cookware, primarily affects the appearance…but the real question is does really compromise its safety or functionality? Let say when we can clearly see no rusting on the surface stainless steel cookware.

https://www.ddcoatings.co.uk/2276/what-is-pitting-corrosion

Rust itself, which is primarily composed of iron oxide (Fe₂O₃), is generally not considered poisonous. It is not toxic in small amounts and is commonly found in nature. However, only ingesting large quantities of rust, particularly if the rust is present on metal objects that may have been exposed to harmful substances.
 

harbinger255

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The statement is generally true.
Pitting is caused by a reaction between chlorine in salt and the stainless steel, particularly when salt is added to cold water. Pitting, which appears as small pockmarks on the surface of stainless steel cookware, primarily affects the appearance…but the real question is does really compromise its safety or functionality? Let say when we can clearly see no rusting on the surface stainless steel cookware.

https://www.ddcoatings.co.uk/2276/what-is-pitting-corrosion

Rust itself, which is primarily composed of iron oxide (Fe₂O₃), is generally not considered poisonous. It is not toxic in small amounts and is commonly found in nature. However, only ingesting large quantities of rust, particularly if the rust is present on metal objects that may have been exposed to harmful substances.
Initial pitting/corrosion will lead to more surface area being corroded... while iron oxide, in small quantities, isn't toxic by itself, the uneven surface can lead build up of bacteria with use over time unless you are REALLY thorough in cleaning...
 

jumpthepig

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Initial pitting/corrosion will lead to more surface area being corroded... while iron oxide, in small quantities, isn't toxic by itself, the uneven surface can lead build up of bacteria with use over time unless you are REALLY thorough in cleaning...

So any idea how F&B indutry deal with such pitting issue?Since SS is now widely used in most kitchens (Big ones are millions worth), expecting them to throw all away after 5 or 10 years?

If surface has no sign of corrosion, should be safe for use tio bo? :ROFLMAO:
 
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harbinger255

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So any idea how F&B indutries deal with such pitting issue?Since SS is now widely used in most kitchens (Big ones are millions worth), expecting them to throw all away after 5 or 10 years?

If surface has no sign of corrosion, should be safe for use tio bo? :ROFLMAO:
As long as you dry them properly after washing and don't subject them to like hard physical wear and tear (like excessive scrubbing (esp using those wire sponge), your SS cookware should last you a long time bah... worst case send in for passivation again... but think most kitchen will just buy new ones

If you are worried about leaching like the first article.. well... only thing regular consumer can do is buy from reputable brands lor... not like you can get a material cert on COO for everything you buy...

Personally I think the article is sensationalized and a bit BS lah....
 

jumpthepig

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As long as you dry them properly after washing and don't subject them to like hard physical wear and tear (like excessive scrubbing (esp using those wire sponge), your SS cookware should last you a long time bah...

Personally I think the article is sensationalized and a bit BS lah....

Quite BS… (y)
 

jeff79

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As long as you dry them properly after washing and don't subject them to like hard physical wear and tear (like excessive scrubbing (esp using those wire sponge), your SS cookware should last you a long time bah... worst case send in for passivation again... but think most kitchen will just buy new ones

If you are worried about leaching like the first article.. well... only thing regular consumer can do is buy from reputable brands lor... not like you can get a material cert on COO for everything you buy...

Personally I think the article is sensationalized and a bit BS lah....
Watch the video i posted earlier. The patient crashed into a shop while driving then the doctor diagnosed him of lead poisoning. Learned that the paitent used a stainless steel vacuum flask for 20 years in badly scratched condition and suspected it as the source of lead poisoning.

All grades of stainless steel do not contain lead. Even china consumer group test report of unsafe vacuum flasks was due to usage of 201 grade stainless steel leached unsafe level of chromium and manganese after filled with acid for 24 hours.

Even the leaded solder at bottom of flask no problem if wash hand after touching.
 
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