Understanding what PTFE tape is used for is important. There are several potential Teflon™ tape uses but ultimately, the requirements of a particular task will determine whether PTFE tape is suitable.
Click here to get more.
PTFE tape is commonly referred to as a thread sealant and many types can help to minimise leakage around certain types of joints. Specific thicknesses of tape can be selected to provide an additional barrier to leakage in ducting. These tapes often feature inherently expansive properties, helping to fill out any small gaps between threads and conduits once they have been wrapped around the inside of a threaded joint.
Common PTFE tape uses include:
The use of plumber’s tape to stop leaks has long been a widespread practice. It is primarily used as a preventative measure when coupling joints together; wrapping the threads of a male component with PTFE tape before mating can help to seal and tighten the joint from the inside. This provides added protection against the risk of future leakage.
PTFE tape can also be used as a temporary short-term solution to help seal plumbing leaks until further work can be carried out. It is generally applied to a joint's exterior to minimise further leakage. However, it is not designed to be a long-term measure for fixing degraded, damaged, or incorrectly fitted joints.
Using PTFE tape for gas pipe sealer applications is common, but it is vital to select the right product for the job. Gas-rated PTFE thread seal tape is widely available, but it tends to be thicker and denser than standard PTFE tape for use in liquid plumbing environments. The latter can be prone to degradation and leaking if used inappropriately for gas pipelines, as it tends to be more porous. This is usually because of having been stretched thinner during the manufacturing process than the more heavy-duty PTFE tapes for natural gas ducting joints.
Due to its chemical inertness, PTFE tape is resistant to both petrol and oil. Therefore, it is often used in automotive applications to seal and lubricate fuel line joints.
Plumber’s lubricating and sealing tape is designed to cope well under moderately high pressure and heat demands. This means that it is broadly suitable for use in environments where it may encounter oil, petrol, diesel and other fuels.
As with most PTFE tape applications, it is good practice to start wrapping slightly below the first line of threading, leaving one full thread circumference exposed at the insertion end of the mating joint. If any small pieces of tape are sheared off where the threads bite together, you can start your wrap a little further back from the endpoint to prevent these material scraps from entering and potentially contaminating connected tanks or fuel lines.
While it can be used, PTFE on compression fittings is not typically required. Thread sealants are not needed with compression fittings because, in this application, the thread itself does not seal the joint. Instead, it is the compression of the ferrule between the pipe and the nut that makes the seal, rendering the use of PTFE tape unnecessary.
The number of turns needed will largely depend on the thickness of the tape you are using. However, as a rule, two or three revolutions will be sufficient for most standard applications.
PTFE tape is a staple component of the plumber's toolkit. Keeping supplies of tape to hand will prove useful should any leaks in plumbing systems occur. PTFE is typically used as either a preventative measure to help secure joints and protect against future leaks or as a short-term solution in the event of more serious damage or leaks.
Pipe joint compounds (also known as pipe dope or pipe glue) can be used instead of PTFE tape. However, it should be noted that these alternatives typically have higher strength than tape so are ideally suited as permanent seals rather than temporary solutions.
Glass has been used for centuries to store food and is generally considered to be the safest material for this purpose. Concerns have been raised recently in blog forums about the presence of lead in glass, including glass cookware. Lead is not typically added to glass as an ingredient, except for leaded crystal which should be avoided. However, lead is everywhere in the environment and any raw material is likely to have some degree of lead contamination.
So, is there lead in glass cookware and does it leach into food?
Glass cookware is made from glass ceramic, which has the same chemical composition as glass but is treated with heat to crystallize the glass. An extensive study done on several types of glassware, including glass ceramic, tested products under several testing conditions including acidic solutions cooked for long periods of time. The glass ceramic products had no detectable levels of lead under any test conditions. You can read more here about the study and other types of tested glassware. Glass ceramic is non-porous so it does not leach or react with acidic foods.
Look for glass cookware and bakeware that meets or exceeds California Proposition 65 standards for lead and cadmium for extra assurance.
Glass ceramic cookware is among the healthiest options but it is not without risk. Shattering is a concern with any glass cookware but glass ceramic is more tolerant of temperature changes and therefore less likely to shatter. Borosilicate glass is less likely to shatter than soda lime glass. All glass cookware should be used with caution and it’s important to carefully follow manufacturer directions.
Luminarc (glass ceramic)
Visions (glass ceramic)
Anchor Hocking (soda lime glass)
Arcuisine by International Cookware (borosilicate glass)
Corningware (glass ceramic). Not all Corningware is glass ceramic. Much of it is stoneware.
Libbey (soda lime glass)
Pyrex (soda-lime glass)
Simax Glassware (borosilicate glass)
Cast iron is made with a blend of iron and steel and cast in a sand mold. While there may be other proprietary ingredients added, lead and cadmium are not found in untreated cast iron. Iron is known to leach into food in significant amounts, often increasing with acidic foods and longer cooking duration. A study by the American Dietetic Foundation found that iron content in spaghetti sauce increased by 945% while that in cornbread increased 28%. For many, the addition of iron to food is viewed as a health benefit because iron deficiency is not uncommon in the U.S. Read more here about how much iron is recommended. Those with a known excess of iron may need to avoid cooking with cast iron.
Cast Iron needs to be regularly seasoned with oil to maintain a relatively non-stick finish and protect against rust. This raises questions about what type of oil to use and if using less-healthy oils creates a risk of its own. Some brands sell cookware pre-seasoned with oil. The types of oil vary by brand with some using healthier oils than others. Since the oil used for pre-seasoning is a small amount and a one-time application, I am more concerned about what oil is used to continually maintain the utensils over time. Some argue that high-smoke point oils are best because when oils are heated above their smoke point, they degrade and give off byproducts that are thought to be carcinogenic. Coconut, avocado, and rice bran oil have high-smoke points. Flaxseed oil is sometimes used because it is a drying oil and creates a durable finish but it has a low smoke point and can become rancid over time.
Beware, if a cast iron product does not need to be seasoned it likely has a non-stick coating. Keep reading to understand concerns about non-stick coatings.
Lodge Seasoned Cast Iron (preseasoned with soybean oil)
Field Company (preseasoned with organic grapeseed oil)
Finex (preseasoned with organic, non-GMO, flaxseed oil)
Lodge Cast Iron Muffin Pans (preseasoned with soybean oil)
Carbon steel is similar to cast iron except is has a slightly higher iron content. Carbon steel typically is comprised of about 99% iron and 1% steel, while cast iron typically has 97-98% iron and 2-3% steel. The different composition allows carbon steel to be lighter than cast iron. It also needs to be regularly seasoned with oil.
If a carbon steel product does not need to be seasoned it likely has a non-stick coating. Keep reading to understand concerns about non-stick coatings.
Lodge Carbon Steel (preseasoned with soybean oil)
Made-In Blue Carbon Steel
Matfer Bourgeat (not preseasoned)
US-ION Wrought Iron (preseasoned with rice bran oil)
This is the only ceramic cookware I recommend. Xtrema pots and pans are 100% ceramic, made only from natural minerals, clay and water. No metals are added as ingredients in this ceramic cookware. Because lead is everywhere in the environment and any raw material is likely to have some degree of lead contamination, it is possible that trace amounts could be present. However, every shipment is tested by government-regulated laboratories to ensure that lead, cadmium and other heavy metals do not leach into food. All testing results, which meet California Proposition 65 limits are posted on their website.
I recommend Xtrema because of the company’s transparency and commitment to producing products that are healthy for humans and for the environment. The extremely hard ceramic cooking surface can’t be scratched by metal utensils or steel wool and doesn’t wear off. NOTE: This cookware is fairly heavy and comparable to the weight of cast iron. It is not entirely non-stick but is fairly easy to clean.
You can receive 10% off non-sale items using this link with the code SaveX10.
Stainless steel can be a safe type of cookware if you use it under certain conditions. Stainless steel is known to leach nickel and chromium into food. Nickel is an essential micronutrient for humans but too much can result in the development of dermatitis. Chromium, a trace mineral in the human diet, is less of a health concern than nickel but can also cause dermatitis. Leaching can occur at different levels depending on the acidity of the food being cooked, the amount of time the food is in contact with the cookware and the age of the cookware.1 Studies show that the amount of nickel and chromium that leaches into food is generally below recommended limits. Stainless steel is exempt from California Proposition 65 testing because OEHHA has concluded exposure from metal alloys to be minimal and below thresholds required for warnings.2
However, if you have a known or suspected nickel or chromium sensitivity it may be best to avoid all stainless steel. Read more here about nickel and chromium levels from cooking with stainless steel and possible health effects.
You can follow these steps to minimize nickel and chromium exposure:
Avoid cooking highly acidic foods for long cooking durations. (consider cooking chili or tomato sauce in a glass stock pot.)
Wash new stainless steel before use and follow this process before using: Cook a solution of 50% vinegar and 50% water for a 2 hour period and discard the solution. Repeat this process 6 times.3 Studies show that stainless steel leaches significantly more nickel and chromium when it is new and levels off after following this process.4
Consider products that use 430 grade stainless steel (18/0) which contain only trace amounts of nickel. The tradeoff is 430 stainless steel has a little less stain and corrosion resistance than stainless steel made with nickel and requires a little extra care. Be sure to follow manufacturer directions for use and maintenance. There are only 2 products that I have found that have a non-nickel steel used on the inner layer that comes in contact with food. Nöni by SOLIDTEKNICS is a solid piece of non-nickel steel and Homi Chef has a non-nickel, 430 steel on the inner layer. Some products claim to be made of 430 steel but only use it on the outer layer that touches the stove so that it can be used with induction cooktops. If I find other brands with a non-nickel inner layer I will add them to the list.
Stainless steel is not considered a good conductor of heat so many stainless steel pots and pans have a core layer of aluminum or copper. This means that a layer of aluminum or copper is sandwiched between layers of stainless steel and do not come in contact with food. However, if you have a pot or pan with a scratch deep enough to expose the core, you should replace it out of caution. One manufacturer confirmed their top layer of steel is .015” thick. That is about the thickness of an average fingernail. It’s not very thick, but it is thick enough that you would be able to feel a groove if you ran your finger over it. If the core is copper you would be able to see the core if exposed through a scratch. Keep in mind though, that leaching is partly dependent of the surface area of the material. A very small amount of the core material would be exposed from a deep scratch, limiting the amount of leaching.
Make sure you are buying uncoated stainless steel. Some of these brands also sell non-stick coated products.
If you want to learn more, please visit our website JVC.
All Clad D3 (430 outer layer, aluminum core, 304 inner layer)
Cutco (430 outer layer, aluminum core, 304 inner layer)
Homi Chef (430 inner and outer layer and aluminum core)
Made In uncoated stainless. (430 outer layer, aluminum core, 304 inner layer)
(Note: Made In also has a stainless steel line with a black non-stick interior which is not recommended.)
Nöni (solid non-nickel stainless steel)
360 Cookware (304 stainless steel)
All Clad D3 (18/10 stainless steel with aluminum core)
HKJ Chef (18/10 stainless steel)
This is a particularly challenging category to evaluate because enamels differ in how they are formulated, applied and fired. Most companies consider their formulas and processes to be proprietary and do not disclose them. Porcelain enamel cookware is made primarily of silica sand, soda ash borax and cobalt oxide that are melted together, ground into a powder, then applied to metal cookware and fired at high temperatures. Metals such as cobalt, antimony, arsenic or nickel may be added to improve adherence to the metal base. Cadmium is sometimes used to make bright exterior colors such as red, yellow and orange. Additional substances can be added for functionality including Teflon.
There is little research available on migration of heavy metals from porcelain enamel. Additionally, California Proposition 65 only sets migration limits for lead and cadmium in cookware so it doesn’t tell you about levels of other heavy metals or toxicants.
In , the International Organization for Standardization (ISO) established a new standard for vitreous and porcelain enamels that sets migration limits for 16 heavy metals. The standard was set because of evidence of the presence of metals including aluminum, lead, cadmium, cobalt and nickel. The German Federal Institute for Risk Assessment studied enameled grill grates and found high levels of aluminum, antimony, arsenic and nickel.5 The new ISO standard is voluntary, so manufacturers are not required to meet it, but it will be helpful to identify if there are safer porcelain enameled products. I have not yet found any brands that meet the new standard but if I find any particular brands, I will identify them here.
Graniteware
Le Creuset Enamel Cast Iron and Enamel on Steel
Lodge Enameled Cast Iron
Staub Cast Iron
Like porcelain enamel, ceramic stoneware is hard to evaluate because glazes differ in how they are formulated, applied and fired. Unlike porcelain enamel, metals are not needed to adhere ceramic glaze to its base. However, they may include other additives. For example, formulas may include titanium dioxide to make white interior glazes or aluminum oxide to stiffen the glaze.
Manufacturers that do not add lead or cadmium as an ingredient to their products and provide evidence that they meet California Proposition 65 migration levels are less of a concern, but risks remain about other unknown and untested substances.
Be particularly cautious of stoneware that is not made by a reputable company. A study of ceramics from Nigeria found high levels of leaching lead, cadmium, arsenic, and chromium.
Le Creuset Stoneware
Lodge Stoneware
Staub Ceramics
Anodizing is an electrochemical process that converts the metal into a corrosion-resistant finish. This keeps the aluminum from leaching but the finish may degrade over time. Unfortunately, I was not able to find any research that measures leaching from anodized aluminum. All studies found are on untreated aluminum. Also, California Proposition 65 does not require testing for aluminum. Aluminum cookware that is anodized should minimize leaching but without evidence I don’t recommend it.
Silicones are considered by some health organizations to be safe. Health Canada states, “There are no known health hazards associated with use of silicone cookware. Silicone rubber does not react with food or beverages or produce any hazardous fumes.”6
However, some studies are finding that silicones are not completely insert and can release certain toxic substances at low level. Studies are still limited and most focus on a type of siloxane group, cyclic volatile methyl siloxanes (cVMS), which are by-products of silicone manufacturing. The health effects of cVMS are debated but in the European Chemicals Agency added 3 (D4, D5, and D6) to their Candidate List of substances that may have serious effects on human health and the environment.
Some studies are finding that silicone bakeware can leach cVMS into food, particularly at high temperature (above 300°) and into high fat food. For example, migration into meatloaf was higher than into cake.7,8 Greater migration was found in new, unwashed molds.
Silicones, like plastics, can include a mix of chemical additives, fillers, and raw material impurities. There are few studies that focus on the migration or health effects of these potentially harmful ingredients. You can read more here about the toxicity of silicone.
Many new, non-stick cookware products made with ceramic coatings claim they are non-toxic and a safer alternative to non-stick cookware with PTFE or PFOA coatings. This type of cookware is unproven as a truly safe alternative and there are multiple areas of concern.
Nanoparticles: Ceramic or “sol-gel” coatings usually contain ceramic nanoparticles that are applied in a thin coat to the surface of the cookware.9 Some use titanium dioxide nanoparticles which according to this study migrate into food, particularly after the coating is scratched from normal use. Chronic exposure to titanium dioxide nanoparticles has been linked to immune disruption and precancerous lesions in the gut.10 The use of nanoparticles in food contact materials is not yet well studied and more research is needed.
Degradation: According to a major supplier of all types of coatings, the best ceramic coatings last just 15% as long as PTFE-based coatings.11 Where does the coating go? I think it’s safe to assume that the coating ends up in your food.
Unknown Additives: Ceramic coating formulations can be combined with epoxies, acrylics, or alkyds to give them additional functionality.12 Many manufactures will not release the ingredients in their coatings because they consider them proprietary. Some hybrid ceramic coatings also contain PTFE.
Limited Regulation : Cookware for noncommercial use is exempt from FDA regulation. That means that one can’t assume that ingredients in cookware that come in contact with food have been tested and proven safe.13, 14 The FDA does stipulate that if non-stick coatings are found to “adulterate food with unsafe substances” immediate action will be taken. That’s too little too late. While California Proposition 65 provides stringent regulations for lead and cadmium in cookware it does not currently regulate nanoparticles, PTFE, aluminum, non- airborne titanium dioxide, nor other cookware ingredients of concern.15
It’s possible that there are some safer options within this category and I will update the guide accordingly should I learn of them.
Caraway
GreenLife
Greenpan
Gotham Steel
Healthy Legend
Our Place Always Pan
Zwilling J Henckels Spirit Cookware
There are bloggers who use XRF equipment to test for lead in consumer products including cookware. XRF instruments test for lead content, while California Proposition 65 and federal regulations (in the U.S., Canada, EU, and others) use laboratory methods that test for leaching. Leach testing uses acidic solutions to see if any heavy metals that may be added or present in raw materials are extractable, meaning they can leach out of cookware and into food. Some bloggers have written about lead content (which says nothing about leaching) in Xtrema, Visions glass cookware, porcelain enameled cookware and others. I personally base my recommendations on leach testing and specifically look for California Prop 65 because it has the most stringent lead leaching limits. Because there is no safe level of lead, I applaud these bloggers efforts and desire to avoid out of caution anything with lead content whether or not it leaches out into food. But, in this case there is an abundance of independent research that shows Xtrema and Visions do not leach into food. And there are few safe alternatives. You could choose to use stainless steel and cast iron exclusively but you would be exposed to greater amounts of nickel and iron. If that seems like a better alternative for you, that’s fine. My preference is to rotate a larger number of cookware materials to limit any one exposure. I have laid out the facts so that you can make the choice that is right for you and your family.
A final note… I sent my own Xtrema pot, which I have used for years and regularly subjected to steel wool scrubbers and dishwashing, to an independent lab to be tested for lead because I have read (unsubstantiated) claims that leaching from Xtrema increases over time even if it doesn’t leach at the time of testing. Even though this was tested at a lab I’m not claiming the result is significant because it is just one sample. I did it simply to satisfy my own curiosity. The results show no detectable levels of lead.
Xtrema large skillet. This is a workhorse in my kitchen.
Xtrema small and large saucepans. I use these for pasta and sauces, with the exception of acidic foods.
Visions ceramic glass Dutch oven. This replaced the Le Creuset I used for years. I use this to make highly acidic foods that require long cooking times like chili and tomato sauce. I have to admit it makes me a little nervous cooking with glass and I worry about shattering but I’m getting used to it.
Cast iron muffin pans. These replaced my silicone muffin pans that I had used for years.
Borosilicate glass loaf pan. I use these for meatloaf and breads.
Pyrex soda lime glass baking pans.
Stainless Steel cookie trays and sheet pans
Stainless Steel small skillet. If I were in the market for a new stainless steel pan I would buy the Nöni pan.
Want more information on porous teflon? Feel free to contact us.