Costco is known for offering high-quality products at competitive prices, and many of their options are healthier than what you’ll find at other retailers. But just because something is sold at Costco doesn’t mean it’s free from harmful chemicals, heavy metals, or endocrine disruptors. While the store does carry plenty of safer, non-toxic options, some items can introduce unnecessary toxins into your home. Awareness of which products pose a risk allows you to make informed choices and protect your long-term health.
Understanding Toxins in Everyday Products
Toxic exposure isn’t always obvious. Many chemicals accumulate in the body over time, making their effects difficult to trace to a single source. Certain products contain compounds that interfere with hormone regulation, increase the risk of neurological decline, or contribute to chronic inflammation. With decades of research in environmental science, I’ve studied how everyday exposure to synthetic chemicals, heavy metals, and air pollutants affects human health. While some exposures are unavoidable, there are simple ways to reduce your toxic load by avoiding certain products. Costco has many great options, but some household staples aren’t as safe as they appear.
Aluminum Foil and Parchment Paper: Overlooked Kitchen Dangers
Aluminum foil is a convenient kitchen tool, but it comes with a significant downside—aluminum exposure. When heated, aluminum foil can leach into food, particularly when cooking acidic or salty dishes. Over time, excess aluminum in the body has been linked to neurological disorders, including cognitive decline and neurodegenerative diseases. Even small, repeated exposures can accumulate, making it important to minimize contact with aluminum, especially in cooking. Instead of using foil, glass containers or stainless steel baking sheets provide safer alternatives.[1]
Parchment paper isn’t always a safer choice. Many brands, including those found at Costco, use a silicone coating to create a non-stick surface. When exposed to heat, this coating can release siloxanes, compounds associated with hormone disruption, liver toxicity, and potential carcinogenic effects. Some research suggests that these compounds begin breaking down at temperatures as low as 200°F, meaning they could be released even during moderate baking. Opting for unbleached, non-coated parchment paper or reusable silicone baking mats made from food-grade silicone can help reduce this risk.
Tuna and the Problem with Mercury Contamination
Tuna is a protein-rich food that many people consider a healthy staple, but it frequently contains unsafe levels of mercury. As a heavy metal, mercury builds up in the body over time, leading to neurological issues, cardiovascular problems, and developmental concerns. Because mercury accumulates in the food chain, larger fish like tuna have some of the highest concentrations.[2]
If you want to eat tuna while minimizing risk, look for brands that test for heavy metals, such as Safe Catch. Skipjack tuna is another lower-mercury option compared to larger varieties like albacore. However, even with lower-mercury choices, it’s best to limit consumption and rotate seafood sources. Smaller fish like sardines, anchovies, and wild-caught salmon provide omega-3s without the same heavy metal concerns.
Plug-In Fragrances: Hidden Chemicals in Your Air
Air fresheners, particularly plug-in fragrances, are one of the most toxic products commonly used in homes. They may create a pleasant scent, but they do so by releasing a mix of synthetic chemicals that can contribute to poor indoor air quality and long-term health issues. Many of these fragrances contain phthalates, volatile organic compounds (VOCs), and other compounds that act as endocrine disruptors, interfering with hormone balance. Studies have linked prolonged exposure to artificial fragrances with respiratory issues, heart disease, and an increased risk of cancer.
Unlike food toxins, which can be managed through diet and detoxification, airborne toxins are continuously inhaled, making them difficult to avoid once they’re in your home. Synthetic fragrance chemicals also linger on fabrics, furniture, and walls, contributing to prolonged exposure. Instead of plug-in air fresheners, natural alternatives like essential oil diffusers, beeswax candles, and fresh air circulation provide a safer way to maintain a clean-smelling home.
Better Alternatives for a Low-Toxin Lifestyle
Avoiding these products doesn’t mean sacrificing convenience. There are safer options for every item on this list. Instead of aluminum foil, opt for glass baking dishes, stainless steel cookware, or unbleached parchment paper without a non-stick coating. For seafood, switch to lower-mercury options like wild-caught salmon or sardines, which offer the benefits of omega-3s without the same heavy metal exposure. To freshen your home naturally, choose high-quality essential oils, beeswax candles, or open windows regularly to improve indoor air quality.
Making Smarter Choices for Long-Term Health
Creating a healthier home isn’t about eliminating every possible exposure to toxins—it’s about making informed choices that reduce the biggest risks. Costco has plenty of non-toxic and high-quality options, but knowing which products to avoid makes a big difference. Small, consistent changes—like switching to safer kitchen tools, choosing lower-toxin foods, and eliminating artificial fragrances—help support long-term health and lower overall toxic burden.
Final Thoughts: Awareness Leads to Better Health
Many people assume that if a product is widely available, it must be safe. However, regulatory standards don’t always reflect long-term health risks, and many harmful chemicals make their way into everyday products without consumers realizing it. Raising awareness about hidden toxins helps more people shift to a healthier lifestyle. If you know someone who frequently buys these items, sharing this information can help them make smarter choices. Costco offers many great non-toxic options, and with the right knowledge, it’s easy to shop wisely and create a home that supports health rather than undermining it.
References:
- Dordevic, Dani, et al. “Aluminum Contamination of Food during Culinary Preparation: Case Study with Aluminum Foil and Consumers’ Preferences.” Food Science & Nutrition, vol. 7, no. 10, Sept. 2019, pp. 3349–60.
- Bernhoft, Robin A. “Mercury Toxicity and Treatment: A Review of the Literature.” Journal of Environmental and Public Health, vol. 2012, 2012, p. 460508.