Use your knives to prepare food?

Joined
May 18, 2008
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25
I was having dinner with my friend last night, and she is one of the hottest chemist I have seen, a very hot woman; just my type... Oh well, she doesn't have a boyfriend we are not dating or anything, she is just too busy, sometimes working in isolation somewhere...

Oh excuse me, let me go back to the topic :D it was somewhat related to her, because she is a chemist. while we were eating our steaks I talked about knives again, you know, how dull is this possibly 440C steak knife is.

"Yeah, dull and toxic." she responded.
"What? toxic? what is?" I am sure some of you will have the same reaction if hearing that.

Then in the next 10 or 20 min she keep telling me all these chemical reaction between cooking a piece of steak, and making of the steel plate and knives. yeah, I know my steak could be carcinogenicity, but the making of steel and knives? (I am glad I have something I am interested in, or it's gonna be really boring hear those reactions)

The bottom line is, she told me the making of most steel and knives need to add element that are toxic, but we don't need to worry about it, because usually those elements are very low in most knives. Plus our body will take care of them unless the human body has a substantial exposure to the toxic element for a substantial period of time.

Then suddenly I remember all those knives I have are really not that ordinary... so I told her, than she asked me what elements are added to the knives. I named a few, and she said those are somewhat toxic, then later on she came to my house (well nothing special happen that night... ;) ;) we just talked... but I am kind of expecting maybe in a month or so... :D)

After showing her what are mixed in the metal, she said some of them are pretty toxic, but could be stabilized and bound with other elements or compounds after the heat treatment and mixture; however, could possibly still release toxics under certain condition, such as heat.

So I ask her if it will do any harm to the body if used those knives to prepare food? Her answer was "All these elements can and might cause cancers and intoxication if the human body has a substantial exposure to the toxic element for a substantial period of time. Well, that basically means she is not sure... I guess :confused::confused: :D ?

So I did a little research and found some useful information.



Vanadium

Powdered metallic vanadium is a fire hazard, and unless known otherwise, all vanadium compounds should be considered highly toxic. Generally, the higher the oxidation state of vanadium, the more toxic the compound is. The most dangerous compound is vanadium pentoxide.

The Occupational Safety and Health Administration (OSHA) has set an exposure limit of 0.05 mg/m3 for vanadium pentoxide dust and 0.1 mg/m3 for vanadium pentoxide fumes in workplace air for an 8-hour workday, 40-hour work week.

The National Institute for Occupational Safety and Health (NIOSH) has recommended that 35 mg/m3 of vanadium be considered immediately dangerous to life and health. This is the exposure level of a chemical that is likely to cause permanent health problems or death.

Manganese
Manganese compounds are less toxic than those of other widespread metals such as nickel and copper. Exposure to manganese dusts and fumes should not exceed the ceiling value of 5 mg/m3 even for short periods because of its toxicity level. Manganese poses a particular risk for children due to its propensity to bind to CH-7 receptors. Manganese poisoning has been linked to impaired motor skills and cognitive disorders. Essentially, chronic exposure to manganese dust has caused miners to go mad.

Acidic permanganate solutions will oxidize any organic material they come into contact with. The oxidation process can generate enough heat to ignite some organic substances.

In 2005, a study suggested a possible link between manganese inhalation and central nervous system toxicity in rats.It is hypothesized that long-term exposure to the naturally occurring manganese in shower water puts up to 8.7 million Americans at risk.

A form of neurodegeneration similar to Parkinson's Disease called "manganism" has been linked to manganese exposure amongst miners and smelters since the early 19th Century. Allegations of inhalation-induced manganism have been made regarding the welding industry. Manganese exposure USA is regulated by Occupational Safety and Health Administration.


Nickel
Exposure to nickel metal and soluble compounds should not exceed 0.05 mg/cm³ in nickel equivalents per 40-hour work week. Nickel sulfide fume and dust is believed to be carcinogenic, and various other nickel compounds may be as well. Nickel carbonyl, [Ni(CO)4], is an extremely toxic gas. The toxicity of metal carbonyls is a function of both the toxicity of a metal as well as the carbonyl's ability to give off highly toxic carbon monoxide gas, and this one is no exception. It is explosive in air.

Sensitized individuals may show an allergy to nickel affecting their skin, also known as dermatitis. Nickel is an important cause of contact allergy, partly due to its use in jewelry intended for pierced ears. Nickel allergies affecting pierced ears are often marked by itchy, red skin. Many earrings are now made nickel-free due to this problem. The amount of nickel which is allowed in products which come into contact with human skin is regulated by the European Union. In 2002 researchers found amounts of nickel being emitted by 1 and 2 Euro coins far in excess of those standards. This is believed to be due to a galvanic reaction.

phosphorus
Organic compounds of phosphorus form a wide class of materials, some of which are extremely toxic. Fluorophosphate esters are among the most potent neurotoxins known. A wide range of organophosphorus compounds are used for their toxicity to certain organisms as pesticides (herbicides, insecticides, fungicides, etc.) and weaponized as nerve agents. Most inorganic phosphates are relatively nontoxic and essential nutrients. For environmentally adverse effects of phosphates see eutrophication and algal blooms.

Upon exposure to elemental phosphorus, in the past it was suggested to wash the affected area with 2% copper sulfate solution to form harmless compounds that can be washed away. According to the recent US Navy's Treatment of Chemical Agent Casualties and Conventional Military Chemical Injuries: FM8-285: Part 2 Conventional Military Chemical Injuries, "Cupric (copper(II)) sulfate has been used by U.S. personnel in the past and is still being used by some nations. However, copper sulfate is toxic and its use will be discontinued. Copper sulfate may produce kidney and cerebral toxicity as well as intravascular hemolysis."

Well, I don't usually use my expensive knives to prepare food but do you? :D :yawn: :D
 
In this day and age, it seems that practically everything is going to give you cancer...

Well, I'll still be using my knives with food. I mean, kitchen knives are basically big fixed blades aren't they?
 
Just found out I missed one very important point I forgot to mention :o

Actually I wasn't afraid or scared of using some of my old knives to prepare food, after all we all have to use knives in some ways or another my concern is on new metal/steels, I don't know if they add like Vanadium, phosphorus in the metal in the 80s... man, I can't even pronounce some of the names, but nowadays there are so many kinds of new metal/steels coming out of the market and they are adding more chemicals/elements to the steel, I don't think when they first designed or made those steel, it's safety first? like some are called tool steel? or maybe it's just a metal that are well-suited to be made into tools.

I think we should be a bit more careful, after all we still doesn't know what exactly causes caner and "a substantial exposure to the toxic element for a substantial period of time" is gonna be different for everyone, and different body might react to the same amount of the same chemical differently... weight, body shape...etc is gonna affect the result in some ways... plus toxic can accumulate slowly in the body?

So I was wondering just about those new steels like tool steel, D2, M2, S30V, H1... I wonder if there's a research that do on these recent metal/steels ?

Anyway, I am not running around telling people not to use knives to prepare food/cook that is just impossible:D, and I love all these new steel;), but maybe we should be a bit more careful on the new metal on food? but again, it might take as much as eating a bowie sized blade to have affect on us :D
 
Most of the high end kitchen knives are being made from the new steels with no ill effects. I've never had any problems because I use my pocket knife or fixed blade to prepare food.
 
Um ... first off, who made this 440C steak knife? Some of the guys here could get pretty excited about the idea of a 440C steak knife....

Organic compounds of phosphorus form a wide class of materials, some of which are extremely toxic.

Um, yeah. Some of the compounds of nitrogen are extremely explosive, too. Gonna stop breathing air? Oh wait, it's only some of the compounds that are explosive ...

That's just one example, but the whole post is like that -- utter nonsense, totally irrelevant to the theme that using your knives to prepare food might somehow poison you.

My guess is the young lady is not an idiot; you misinterpreted everything she said just like you misinterpreted all the information you found with your "research." :)
lolcat.jpg
 
The amounts that may enter your body are so tiny they would have zero effect IMO.
My mouths full of magnesium fillings for example that is prolonged exposure of a very toxic chemical but its in small amounts so i dont care.
Ive far to many real troubles to worry about crazy shit like this if i did i probably would be to scarred to leave the house.
 
I feel what Cougar is trying to say. I found this when doing a quick search on the toxicity of the main part of all knives: Iron.

Iron poisoning may result in mortality or short-term and long-term morbidity.

But we are speaking about high doses here, and you have to try hard to get high doses absorbed in your blood. It doesn't look likely that more than a few tenths of a µg of steel will end up in your stomach after cutting your foot.
Unless you grind your knives above your food:D

But you're right to be concerned, as the past has showed us that you can't use any steel you like on foot. In the middle ages many people have died of lead poisoning because the poor used lead in all sorts of kitchen equipment, and it got dissolved in things like hot milk.

So I did a quick search myself, and all basic steels used in knives that I know of are needed in some dose by the body. I'm talking about Iron, Chromium,Copper,
Manganese, Molybdenum, Nickel, ...
You can see the minimum doses here.
The only element I couldn't find anything on shortly was vanadium, but all I could find is that it is dangerous for our longs in higher doses.

Your quotes also seem to go about inhalation. But you can also say that oxygen can be toxic in a form: O³ or ozon.

So no need to worry it seems to me. But maybe the knifemakers have something to worry about because they are the ones that have a higher chance of breathing this stuff on a daily base I'm afraid.
 
Knifemakers are much more concerned about inhaling the dusts from grinding handle materials, which actually would be harmful. Really good protection is important. If you're interested you can find plenty of info in Shop Talk.

Although some handle materials are more toxic than others there really isn't any kind of dust that you want to be breathing.
 
Phosphorus? buddy, you're full of… right, phosphorus!
…and I like hot chemist ladies myself )))))))))
 
Lenny, who was the Russian composer who was also a chemist ??...Anyway Jason-perhaps you both should check the water you are drinking .If it has high levels of copper it's probably causing the mental illness you exhibit. After a lifetime as a metallurgist the only thing I've suffered is lead poisoning.'
According to the American Chemical Society there are 80,000 chemicals in regular use that have been invented since 1965 !! No one seems to give much thought to that yet we see all immune system problems on the increase !
The answer is to eat the steak not the knife ! My steak knifes are made of D-2, VG-10 and even my new Fallkniven 3G and my steak is organically grown !
 
It sounds like as long as I don't grind my knives up and snort the dust I'll be okay. I don't think I'm going to lose any sleep over it.
 
Maybe she was just angling for that next date, getting you all hot and bothered.:D
 
I was having dinner with my friend last night, and she is one of the hottest chemist I have seen, a very hot woman; just my type... Oh well, she doesn't have a boyfriend we are not dating or anything, she is just too busy, sometimes working in isolation somewhere...

Oh excuse me, let me go back to the topic :D it was somewhat related to her, because she is a chemist. while we were eating our steaks I talked about knives again, you know, how dull is this possibly 440C steak knife is.

"Yeah, dull and toxic." she responded.
"What? toxic? what is?" I am sure some of you will have the same reaction if hearing that.

Then in the next 10 or 20 min she keep telling me all these chemical reaction between cooking a piece of steak, and making of the steel plate and knives. yeah, I know my steak could be carcinogenicity, but the making of steel and knives? (I am glad I have something I am interested in, or it's gonna be really boring hear those reactions)

The bottom line is, she told me the making of most steel and knives need to add element that are toxic, but we don't need to worry about it, because usually those elements are very low in most knives. Plus our body will take care of them unless the human body has a substantial exposure to the toxic element for a substantial period of time.

Then suddenly I remember all those knives I have are really not that ordinary... so I told her, than she asked me what elements are added to the knives. I named a few, and she said those are somewhat toxic, then later on she came to my house (well nothing special happen that night... ;) ;) we just talked... but I am kind of expecting maybe in a month or so... :D)

After showing her what are mixed in the metal, she said some of them are pretty toxic, but could be stabilized and bound with other elements or compounds after the heat treatment and mixture; however, could possibly still release toxics under certain condition, such as heat.

So I ask her if it will do any harm to the body if used those knives to prepare food? Her answer was "All these elements can and might cause cancers and intoxication if the human body has a substantial exposure to the toxic element for a substantial period of time. Well, that basically means she is not sure... I guess :confused::confused: :D ?

So I did a little research and found some useful information.



Vanadium

Powdered metallic vanadium is a fire hazard, and unless known otherwise, all vanadium compounds should be considered highly toxic. Generally, the higher the oxidation state of vanadium, the more toxic the compound is. The most dangerous compound is vanadium pentoxide.

The Occupational Safety and Health Administration (OSHA) has set an exposure limit of 0.05 mg/m3 for vanadium pentoxide dust and 0.1 mg/m3 for vanadium pentoxide fumes in workplace air for an 8-hour workday, 40-hour work week.

The National Institute for Occupational Safety and Health (NIOSH) has recommended that 35 mg/m3 of vanadium be considered immediately dangerous to life and health. This is the exposure level of a chemical that is likely to cause permanent health problems or death.

Manganese
Manganese compounds are less toxic than those of other widespread metals such as nickel and copper. Exposure to manganese dusts and fumes should not exceed the ceiling value of 5 mg/m3 even for short periods because of its toxicity level. Manganese poses a particular risk for children due to its propensity to bind to CH-7 receptors. Manganese poisoning has been linked to impaired motor skills and cognitive disorders. Essentially, chronic exposure to manganese dust has caused miners to go mad.

Acidic permanganate solutions will oxidize any organic material they come into contact with. The oxidation process can generate enough heat to ignite some organic substances.

In 2005, a study suggested a possible link between manganese inhalation and central nervous system toxicity in rats.It is hypothesized that long-term exposure to the naturally occurring manganese in shower water puts up to 8.7 million Americans at risk.

A form of neurodegeneration similar to Parkinson's Disease called "manganism" has been linked to manganese exposure amongst miners and smelters since the early 19th Century. Allegations of inhalation-induced manganism have been made regarding the welding industry. Manganese exposure USA is regulated by Occupational Safety and Health Administration.


Nickel
Exposure to nickel metal and soluble compounds should not exceed 0.05 mg/cm³ in nickel equivalents per 40-hour work week. Nickel sulfide fume and dust is believed to be carcinogenic, and various other nickel compounds may be as well. Nickel carbonyl, [Ni(CO)4], is an extremely toxic gas. The toxicity of metal carbonyls is a function of both the toxicity of a metal as well as the carbonyl's ability to give off highly toxic carbon monoxide gas, and this one is no exception. It is explosive in air.

Sensitized individuals may show an allergy to nickel affecting their skin, also known as dermatitis. Nickel is an important cause of contact allergy, partly due to its use in jewelry intended for pierced ears. Nickel allergies affecting pierced ears are often marked by itchy, red skin. Many earrings are now made nickel-free due to this problem. The amount of nickel which is allowed in products which come into contact with human skin is regulated by the European Union. In 2002 researchers found amounts of nickel being emitted by 1 and 2 Euro coins far in excess of those standards. This is believed to be due to a galvanic reaction.

phosphorus
Organic compounds of phosphorus form a wide class of materials, some of which are extremely toxic. Fluorophosphate esters are among the most potent neurotoxins known. A wide range of organophosphorus compounds are used for their toxicity to certain organisms as pesticides (herbicides, insecticides, fungicides, etc.) and weaponized as nerve agents. Most inorganic phosphates are relatively nontoxic and essential nutrients. For environmentally adverse effects of phosphates see eutrophication and algal blooms.

Upon exposure to elemental phosphorus, in the past it was suggested to wash the affected area with 2% copper sulfate solution to form harmless compounds that can be washed away. According to the recent US Navy's Treatment of Chemical Agent Casualties and Conventional Military Chemical Injuries: FM8-285: Part 2 Conventional Military Chemical Injuries, "Cupric (copper(II)) sulfate has been used by U.S. personnel in the past and is still being used by some nations. However, copper sulfate is toxic and its use will be discontinued. Copper sulfate may produce kidney and cerebral toxicity as well as intravascular hemolysis."

Well, I don't usually use my expensive knives to prepare food but do you? :D :yawn: :D



SOGJason, you need to hang on this chemist woman. She can afford a bunch of knives for you in the future.
 
Maybe she was just angling for that next date, getting you all hot and bothered.:D

I recommend that you proceed on the basis of this assumption. :D Assume a genuine interest. Now, bear in mind that the feminine variety of romantic interest is usually more about relationship-as-a-whole than about the physical side of it at this stage--so proceed patiently and gently. But take the confidence to proceed.;)
 
I once got a few dates with a hot chemist girl just because I spent some time talking about Hydrogen dioxide, one of the principle chemicals that are released when plants rot. The hydrogen dioxide combining with methane, etc. is what causes a pile of leaves to feel warm. I guess she got hot and bothered by talk of decomposing self-warming leaves.


Anyway, the toxic chemicals in most steels will never effect you. I wouldn't go sucking on Chinese steel nuggets like candy, but frankly you're going to die from something else long before you get sick from using even the crappiest steel knife, especially a stainless steel one. For all intents and purposes, those chemicals are fixed and inert.

Steel isn't inert chemically though, and you can get some interesting effects from it when you want to. Steel is a little bit antimicrobial, which can be cool. Also, when you cut garlic, you can rub your hands on the walls of a stainless steel sink, and there's something in the steel (Iforget what it is) that neutralizes a good portion of the garlic stink on your hands. That's a little chef's trick.

Far more what you can think about, rather than worry about, is when a carbon steel blade isn't patinated. When you get a good handmade Japanese or French carbon steel chef's knife, for example, you really need to use it all the time to develop and maintain a good patina. If you only use the knife once in a while, it will "shed" onto your food, especially onto meats and acidic vegetables. It's certainly not going to kill you, but you'll be able to notice the taste of metal in your food. The carbon blades still shed if you oil them, it's a reaction of the metal with acids, even through the oil layer.

So in other words, if you have old carbon steel blades, either use them all the time, every day, or try to use stainless steel ones.
 
What does she suggest cutting a steak with, then? A piece of obsidian? I've got one or none of those laying around...
 
The bottom line is, she told me the making of most steel and knives need to add element that are toxic, but we don't need to worry about it, because usually those elements are very low in most knives. Plus our body will take care of them unless the human body has a substantial exposure to the toxic element for a substantial period of time.

Then suddenly I remember all those knives I have are really not that ordinary... so I told her, than she asked me what elements are added to the knives. I named a few, and she said those are somewhat toxic, then later on she came to my house (well nothing special happen that night... ;) ;) we just talked... but I am kind of expecting maybe in a month or so... :D)

After showing her what are mixed in the metal, she said some of them are pretty toxic, but could be stabilized and bound with other elements or compounds after the heat treatment and mixture; however, could possibly still release toxics under certain condition, such as heat.

So I ask her if it will do any harm to the body if used those knives to prepare food? Her answer was "All these elements can and might cause cancers and intoxication if the human body has a substantial exposure to the toxic element for a substantial period of time. Well, that basically means she is not sure... I guess ?


Well, I don't usually use my expensive knives to prepare food but do you?

My degree is in chemistry, I work as a materials engineer, and as part of a previous job I did hazard assessments for the chemicals we were using so that I could prescribe the correct protective gear (PPE).

The elements the lady mentioned are, of course, in our knives. They are also bound in the alloy and are not transferred to the food.

So there is no exposure. So you may use your knives.
 
I reject the underlying premise of this thread: that is the existence a "hot chemist girl." One of my college roommates was a chemistry major; there were no, zero, none, nada hot chemist girls to be found. Those boys would get a stiffy if left alone in a room with a upended string-mop, they were so desperate for anything vaguely resembling female companionship.
Carry on,
rats...
 
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