Are Colored Mason Jars Food Safe?

Mason jars are a type of glass jar used for food preservation and storage. They were invented and patented by John Landis Mason in 1858. The sealing lid allows air tight closure, enabling long term storage and canning of foods (Wikipedia). Mason jars remain popular today for storing and preserving jams, sauces, vegetables, and more. Their versatility and effectiveness for home canning has made them a staple in many kitchens.

In recent years, colored mason jars have become popular for their aesthetic appeal. However, some have raised concerns over whether the colored glass affects the safety of these jars for food storage. Colored glass may contain metals like lead that could potentially leach into acidic foods over time. This article examines the safety considerations of using colored mason jars for home canning and food storage.

Jar Materials

Mason jars are made from glass, metal lids, and bands. The glass jars come in a variety of colors, while the lids and bands are typically metal.

Common glass colors for mason jars include clear, amber, green, blue, and purple. The glass can be plain or have colored coatings on the exterior or interior surfaces. These coatings are usually metallic compounds like cadmium or selenium that give the glass its color (Ball® Mason Jars).

The lids for mason jars are made from sheet metal like tin or aluminum. The flat part seals against the rim of the jar, while the band screws on to hold the lid in place. The underside of the lid has a rubberized sealing compound to create an airtight seal (Henflower).

Metallic coatings and pigments are often used to color the glass used for mason jars. However, there are concerns about the safety of certain compounds. Proper testing helps ensure jars are food-safe.

FDA Regulations

The FDA (Food and Drug Administration) regulates the safety of food, food ingredients, and food packaging through various laws and guidances to protect public health. The FDA has authority over all domestic and imported food sold in the United States, except for meat, poultry, and processed egg products which are regulated by the U.S. Department of Agriculture.

Some key FDA regulations related to food jars include:

– The Food, Drug, and Cosmetic Act which prohibits poisonous or deleterious substances from being introduced into food. This applies to materials like glass that may come into contact with food (https://www.fda.gov/food/food-ingredients-packaging).

– Guidance for glass fragments in food specifying that glass particles 7mm or larger are considered hazardous (https://www.fda.gov/media/80348/download).

– Regulations requiring that utensils and food containers be properly cleaned and sanitized as necessary (https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm?fr=110.80).

Lead in Colored Glass

Lead has historically been used in glass manufacturing to achieve brilliant and vibrant colors as well as to increase the brilliance and clarity of glassware. Lead oxide is added to molten glass to provide qualities desirable in fine crystal such as high refractive index, workability, brilliance, and clarity. The addition of lead oxide allows glassmakers to create a range of dazzling colored glass objects.

However, over time there has been growing concern about the potential health risks of lead leaching out of lead crystal glassware into foods and beverages. Lead can be toxic when ingested, especially for young children. This has led many manufacturers to reduce or eliminate the use of lead in glassware.

According to the FDA, leaded glassware made overseas may contain up to 30% lead while leaded glassware made in the US can only contain a maximum of 6% lead. Many US manufacturers now produce lead-free colored glassware using alternative metallic oxides to achieve beautiful colors without the addition of lead. Modern lead-free glass offers comparable qualities of brilliance and clarity while eliminating the risks of lead.

So while lead had been commonly used historically to manufacture fine colored glass, most modern glassware is produced using lead-free methods. Consumers can check labels for lead-free certifications when unsure if glassware contains lead (https://www.gurasu.co.uk/en/blogs/journal/test-title/). This allows for safely enjoying the beauty of colored glassware without lead exposure.

Safety Testing

Several studies have been conducted by independent organizations and labs on the safety of using colored glass jars for food storage. These studies focus specifically on the potential for harmful chemicals to leach from the colored glass into the food contents.

One key study from the Journal of Agricultural and Food Chemistry analyzed the lead leaching from antique colored glassware into acetic acid solutions, simulating acidic foods like vinegar and tomatoes (Source). They found significant levels of lead contamination in the acid solutions after just one day of storage in some colored glass containers. However, lead leaching was negligible in modern colored glass jars.

Additional leaching tests by the FDA and glass manufacturers have analyzed the migration of metals, chemicals, and pigments from colored glass under typical household usage conditions (Source). These comprehensive safety tests confirm that modern colored glass jars and bottles are formulated to prevent harmful leaching, making them safe for dye, cosmetic, and food storage use.

Acidic Foods

When canning acidic foods like fruits, tomatoes, or pickles, it is important to achieve the proper acidity for safe preservation. The acidity helps prevent the growth of Clostridium botulinum bacteria that can lead to botulism poisoning. For boiling water canning methods, a pH of 4.6 or lower is recommended (1).

The color of a mason jar does not directly affect the acidity level of preserved foods inside. However, darker colored jars like cobalt blue, green, or purple can block more light compared to clear glass. Exposure to light can cause some degradation of acids over time through oxidation. So darker colored jars may help slightly better preserve the original acidity of canned goods by limiting light exposure (2).

When preparing recipes for canning, it is ideal to use vinegars that are labelled 5% acidity like white distilled vinegar. Adding an appropriate amount of these vinegars can reliably lower the pH of foods to a safe level below 4.6 for water bath canning. The vinegar helps create the proper acidity no matter what color jar is used for storage.

(1) https://extension.psu.edu/acidifying-canned-products-for-safety

(2) https://foodinjars.com/blog/canning-101-acid-and-ph-in-boiling-water-bath-canning/

UV Light Protection

Colored glass jars, especially amber or dark colored glass, provide excellent protection against UV light compared to clear glass jars. According to Infinity Jars, amber and other dark colored glass blocks nearly all UV light from penetrating the jar. Clear glass blocks about 30% of UV rays while amber glass blocks up to 98% of damaging UV light.

The tinting in colored glass jars helps prevent degradation of the foods and ingredients stored inside. UV light can break down certain vitamins, oils, and other sensitive substances. Using an amber or dark tinted jar will help preserve freshness and potency much better than clear glass.

Brands like Ball now offer amber glass mason jars that block 99% of UV light to protect contents like spices and herbs. Colored glass jars are ideal for storing teas, herbs, oils, kombucha, and other light-sensitive ingredients.

Recommendations

When using colored glass jars, it’s important to keep food safety in mind. The U.S. Food and Drug Administration (FDA) reports that many decorative glassware products fall under their jurisdiction for safety regulations (1). While colored glass is generally considered safe, there are some best practices to follow.

First, make sure any jars used for canning, storing, or serving food meet FDA guidelines. Look for lead-free colored glass without paints or pigments that could leach into foods over time (2). Stick to reputable, food-safe brands when purchasing colored jars.

It’s also best to handwash colored glass in warm, soapy water instead of the dishwasher. The harsh heat and detergents can cause decorative coatings to deteriorate faster. Limit use of colored jars for acidic foods like tomatoes, citrus, or vinegar that may react with the glass over prolonged contact.

In general, colored glass jars are safe for most applications if care is taken to choose lead-free products from reliable suppliers. Following best practices for use and care will help colored glass jars retain their beauty while safely storing and serving food.

(1) https://mostlovelythings.com/how-to-make-colored-glass-jars-and-get-the-vintage-look/

(2) https://wallabygoods.com/products/colored-mason-jars

Alternatives

There are a variety of alternatives to colored glass mason jars for food storage. Some popular options include:

Silicone Food Bags

Silicone food bags like Stasher bags provide an airtight, reusable and durable option for food storage. Silicone is non-porous and won’t leach chemicals into food. Silicone bags are dishwasher, microwave and freezer safe. However, they can be prone to staining from foods like tomatoes and turmeric. They also have a high upfront cost compared to disposable bags or containers.

Source: https://www.nytimes.com/wirecutter/reviews/best-food-storage-containers/

Beeswax Wraps

Beeswax wraps like Bee’s Wrap provide an eco-friendly and natural alternative to plastic wrap. They create an airtight seal to preserve foods. However, beeswax can melt at high temperatures so may not suitable for hot foods. They also need to be washed regularly in cold water which can impact longevity.

Source: https://greenecofriend.co.uk/eco-friendly-food-containers/

Glass Storage Containers

Glass storage containers like Pyrex are nonporous, non-reactive and won’t leach chemicals. They are typically oven, microwave, dishwasher and freezer safe. Glass containers are durable but can break if dropped. Vintage Pyrex containers avoid issues with lead in colored glass.

Source: https://www.greenhive.io/blog/toxin-free-and-plastic-free-food-storage-containers

Conclusion

The safety of colored jars used for food storage depends on a few key factors. The type of glass and coloring pigments are important to consider, as some older colored jars may have contained lead or other heavy metals in the glass. Newer jars colored with food-safe pigments are a safer option. While glass keeps foods protected from many risks, highly acidic foods may react with the glass and put more lead or chemicals into the food over time. For short-term decorative storage, colored jars appear to be safe, but extended use is not recommended, especially for very acidic items. Clear glass jars or stainless steel containers may be a safer choice for long-term canned food storage.

Overall, colored jars can be used carefully for some decorative and short-term food storage needs. However, regular consumption of foods stored long-term in colored glass jars is not generally recommended. When deciding whether to use colored jars in your kitchen, consider the type of food, storage duration, jar material, and potential risks before making a choice.