Kitchen equipment

Is Rust On Mason Jar Lids Dangerous?

John Landis Mason, a tinsmith, invented the Mason jar in 1858. The jar has a glass body and a screw thread that attaches the metallic ring to the body. It also has a metallic lid with a silicone gasket attached to the inner part of the lid.

Mason jars have gained popularity over the years. They have several uses in the kitchen, including storage and canning.

Unfortunately, Mason jar lids are prone to rust. You may notice rust on the cover after a few uses. When this happens, you may wonder whether the rust on Mason jar lids is dangerous.


Rust usually consists of iron oxide, which isn’t dangerous if you accidentally consume it in small amounts.

However, the rust may make your Mason jar not seal properly, which may, in turn, make the contents of your jar hazardous. Consuming the contents may make you ill.

This article discusses the causes of rust on Mason jar lids, how to prevent rusting, how to remove rust, and alternatives you can use in its place.

Also, Check Out: Canning Food Preservation Ideas For Beginners.

Why do Mason Jar Lids rust?

The body of the Mason jar never rusts because it consists of glass. Therefore, you can use it multiple times. The only way it can become unusable is if it breaks or chips.

On the other hand, the Mason jar lids are susceptible to rust. The amount of rust significantly depends on;

· The material used to make the lid.

· The environment.

· The ph of the food you store in the jar.

Also, Check out Water Bath Canning Methods.



Most manufacturers use tin-plated steel to make Mason jar lids and rings. Tin-plated steel is highly susceptible to corrosion.

Therefore, rings and covers made of this type of steel tend to rust since they are not water-resistant.

Usually, manufacturers advise users against using the lids more than twice for this reason. This explains why most Mason jar lids are disposable.


Mason jars tend to rust when stored in humid environments. Water molecules in humid environments cause the lids to rust easily since tin-plated steel is not water-resistant.

Storing the jar with its lid on for an extended time may also result in rust.

Food ph


Like water, acid rusts tin-plated steel. It makes the lids rust way faster. For this reason, most manufacturers coat the inside of the Mason jar lids with a chemical known as biphenyl (BSA) to protect the cover from acid corrosion.

If you store food high in acid, e.g., tomatoes, in a jar whose lid doesn’t have BSA, the acid will corrode the cover, making it rust from the inside.

Consequently, whatever is in the jar is exposed to pathogenic bacteria and prone to spoilage.

Can You Keep Unopened Pickles At Room Temperature? Click to Read.

Is the rust dangerous?


Rust on Mason jar lids comprises iron oxide. Generally, iron oxide does not harm the human body, so ingesting a little bit of it may not cause any health issues. 

The main concern with rust on Mason jar lids is that it may cause a sealing breach, especially if the rust is excess. If your jar does not seal properly, its contents may become hazardous.

Consuming the contents may result in health complications.

To avoid this, I suggest buying disposable Mason jar lids and rings. They are pretty affordable, and you can be sure that rust won’t interfere with the sealing process. 

How to prevent rusting


Mason jar lids are prone to rust, but there are a few things you can do to slow down the rusting process.

For starters, store them in a dry place. As discussed above, humid temperatures make Mason jar lids rust faster, so keeping them in a dry place will prevent that.

Another tip is to hand wash your lids instead of washing them in your dishwasher. Immediately you are done washing, dry them and store them in a dry place. Never leave the covers wet after washing.

These two tips will make your lids last much longer.

How to remove rust


If your Mason jar lids already have rust on them, you can opt to use the Mason jar for other uses, like storing your knick-knacks and using them for your DIY projects. However, if you’re still keen on using the jar for canning, you’ll have to get rid of the rust first.

To remove the rust, you’ll need distilled white vinegar. Soak a clean cloth in distilled white vinegar, then use it to scrub off the rust on your lid. Be sure to scrub off any orange streaks too.

Once you’ve scrubbed off the rust, use warm, soapy water and a sponge to wash the rings and lids. After washing them, dry them immediately and store them away in a dry place.

If the quantity of rust is a lot, you should soak the lids in distilled white vinegar instead of using a cloth soaked in vinegar.

The vinegar will dissolve the rust, making it easier for you to wash it off. If the rust is still stubborn, use steel wool and soap to remove it.


Alternatives to Mason jars

Mason jars are pretty versatile, but the downside is that the rings and lids are prone to rust.

Additionally, the BSA coating on the lid is not entirely safe. Luckily, there are suitable alternatives you can use in place of Mason jars. They are;

Glass jars with bamboo lids


Glass jars with bamboo lids usually come with silicone rings. Unlike Mason jar lids, they never rust.

The downside with these jars is that they are not entirely leakproof. Therefore, they may not be the ideal choice for canning. You can use them to store or transport thicker foods.

Le Parfait jars

As their name suggests, these jars originate from France. Their lids are made of glass and permanently held in place by a metal hinge and clasp. Additionally, they have rubber seals.

These jars are ideal for canning and storage in general.

Weck jars


These jars originate from Germany. Usually, they have glass lids and rubber sealing rings. Weck jars come in various sizes and are pretty attractive. Their covers are held on by clips made from stainless steel.

Quarto Stagioni jars

These are Italian jars that feature a screw-on single-piece lid that is BPA-free. Unlike Mason jar lids, their covers are not prone to rust. Additionally, they are easy to use.

Stainless steel jar lids


You can opt for stainless steel lids with screw bands to avoid rusting. Their main advantage is that they preserve your food better since they create a tighter seal.

It would be best not to use these lids for canning because they don’t pop. They are only ideal for storage.

Tattler lids

These are reusable plastic canning lids that come with rubber seals. Unlike Mason jar lids, they do not have a BSA coating, which is safer.

These lids are pretty popular in the United States and make for a great alternative to Mason jar lids.



Mason jars are pretty popular in American households. They have several uses, including canning and storage.

Unfortunately, Mason jar lids are prone to rust because the material manufacturers use to make them is tin-plated steel. 

Use the tips discussed above to prevent rusting. If the lids have already rusted, follow the steps above to remove the rust. Alternatively, use the other jars listed above.

Rust on Mason jars’ lids may not cause serious health issues, but it may result in sealing breaches that may contaminate your food. Be sure to change the cover after a single-use or use disposable lids to be safe.

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