Glass breaks when it experiences thermal stress, i.e., exposure to uneven heat distribution. This temperature imbalance causes the glass to expand unevenly, putting strain on its structure. When one area of glass heats up, it expands.
Thermal Stress: Glass and crystal can be sensitive to temperature changes. Rapid heating or cooling can create thermal stress, causing the material to expand or contract unevenly. If the stress exceeds the material's strength, it can shatter.
Sometimes Tupperware containers themselves can also crack or become warped by being exposed to excess heat such as in the microwave or dishwasher (even if instructions tell you it's microwave and/or dishwasher safe). If this is the case, it's time to toss the broken or non functioning pieces.
With care, glass containers will last almost indefinitely, and if you do discard of them, they're 100 percent recyclable.
While there is no set timeframe for replacing plastic food containers, experts say they should be tossed out when they show visible wear, chips, cracks, or signs of stains and odors.
Glass provides a healthier alternative - When it comes to health benefits and safety in the kitchen, glass is a better material. Even BPA-free plastics are prone to releasing toxic chemicals if heated. This makes washing, microwaving, and heating plastic containers a threat to your health.
Tupperware® brand products are warranted by Tupperware against chipping, cracking, breaking or peeling under normal non-commercial use for the lifetime of the product. Please contact our Customer Care at 1-800-TUPPERWARE (1-800-887-7379) for assistance or through chat at Tupperware.com.
Although glass Tupperware is heavier and easier to break, overall it is the better choice. By using glass Tupperware, you can be certain that your food will not be contaminated by harmful chemicals. Glass is natural, sustainable, and recyclable.
If any of your containers have a #3, #6, or #7, those should be disposed of because they are considered high-risk plastics. If you're going to use one of the safer plastics, it's best not to store acidic or greasy foods in them.
Extremely high heat (of more than 150 C) and rapid temperature changes (of more than 15 C) can cause the glass to break by itself. When glass heats up, it expands. When it cools down again quickly, it doesn't have time to contract at the same pace and pulls inwards, creating stress points that lead to cracks.
Locating Stress Cracks
Origin at the Edge: Because the glass is more vulnerable to pressure and stress, stress cracks frequently start there. Usually, they have a straight or slightly curved line that extends inward.
Spontaneous breakage of tempered glass is most commonly caused by chipped or nicked edges during installation, stress caused by binding in the frame, internal defects such as nickel sulfide inclusions, thermal stresses in the glass, and inadequate thickness to resist high wind loads.
Thermal Stress:
When glass is exposed to a sudden temperature change, such as moving from a cold environment to a hot environment or vice versa, different parts of the glass will expand and contract at different rates. This creates stress points in the glass, which can cause it to crack or shatter.
Cracks are easier to spot in clear glass, but even uncracked, seemingly perfect glass containers can break if overheated. Unless they're specifically marked as microwavable, many appliance makers recommend limiting glassware to three minutes of cooking time to prevent the possibility of shattering.
Glass and ceramic dishware are usually safe for microwave use, but there are exceptions like crystal and some handmade pottery. When it comes to glass or ceramic plates, bowls, cups, mugs, mixing bowls or bakeware, you should be in the clear as long as it doesn't feature metallic paint or inlays.
The answer to the question to, “How long do Tupperware containers last?” is they do last a very long time. That's a good thing and a bad thing. If they are over about 10 years old, it's probably time to stop using them for food.
Old Tupperware, especially those over a decade old, might contain hazardous chemicals like cadmium, lead, and arsenic. These can leach into your food, posing significant health risks. Vintage Tupperware products are particularly concerning due to the potential leaching of additional harmful substances.
But when it comes to storing food in the refrigerator, many people wonder if glass containers are safe to use. The answer is yes, glass containers are safe for storing food in the refrigerator, as long as they are made of high-quality glass that can withstand low temperatures.
In September this year, Tupperware Brands filed for bankruptcy in a Delaware court as demand fell, losses mounted, the stock slumped and debt rose. Tupperware revolutionized food and kitchen storage in the latter half of the 20th century and became a household name.
Tupperware will repair / replace any Tupperware product, or any part thereof, that, under normal domestic use, shows a manufacturing defect, such as: warping, cracking, peeling, splitting and other functional issues. The colour of the replacement may vary from the colour of the original product.
Tupperware warrants that Tupperware® brand products that are subject to the Limited Lifetime Warranty will not chip, crack, break, peel or warp (as such terms are defined in the “Definitions” section below), when used under normal, non-commercial use, for the lifetime of the product.
The benefits of glass packaging are clear: it's sustainable, being 100% and infinitely recyclable, reusable, and refillable. It's inert, with no synthetic chemicals, making it safe to store food and drinks in.
Can I put glass in the freezer? Only if it says freezer-safe (usually tempered glass). Otherwise, it can crack and that's no fun. Also make sure to remember that liquids expand, and glass has no wiggle room, so if you're freezing in a freezer-safe glass container, you still want to leave a little room at the top.
Unlike plastic containers, glass won't warp, melt, or release harmful chemicals when exposed to heat. You can confidently use glass for all your cooking needs, from lasagnas in the oven to reheating soup in the microwave.