What types of plastic bottles should be avoided?

September 23, 2025 •

4 min read

Research indicates that microplastic particles are now present in human blood, breast milk, and organs. This troubling reality highlights the importance of knowing what types of plastic bottles should be avoided to minimize your exposure to potentially harmful chemicals and improve your general health.

Quick Summary

For optimal health, you should avoid plastic bottles with recycling codes #3 (PVC), #6 (PS), and #7 (polycarbonate with BPA). Look for safer alternatives like glass or stainless steel to reduce exposure to chemical leaching.

Key Points

Avoid Plastics #3, #6, and #7: These are the most problematic types of plastic, known to leach toxic chemicals like phthalates, styrene, and bisphenols.
Don't Reuse or Heat #1 (PET): While common for single-use water bottles, this plastic can leach antimony, and the risk increases with heat and reuse. Do not refill these bottles.
Opt for Safer Plastics or Alternatives: If you must use plastic, choose containers with recycling codes #2, #4, or #5. The best choices are non-plastic, such as glass or stainless steel.
Heat Amplifies Leaching: Never microwave food or drink in plastic containers, as high temperatures accelerate the breakdown of the plastic and the release of harmful chemicals.
Beware of "BPA-Free" Claims: Some BPA-free plastics use similar hormone-disrupting chemicals like BPS. A "BPA-free" label doesn't guarantee a product is entirely safe from bisphenols.
Replace Old or Worn-Out Bottles: Scratched, cloudy, or faded plastic bottles are more likely to leach chemicals and should be replaced to ensure safety.
Reduce Overall Plastic Use: The best way to minimize exposure is to reduce your consumption of single-use plastics and switch to durable, long-lasting alternatives.

Understanding Plastic Recycling Codes

To make informed decisions about your plastic bottles, you need to understand the Resin Identification Codes (RICs) found on the bottom of containers. These are the familiar numbers inside a chasing-arrows triangle, ranging from 1 to 7. While originally created for recycling purposes, these codes also offer clues about the plastic's chemical composition and potential health risks. Codes 1, 2, 4, and 5 are generally considered safer for food and beverage use, while 3, 6, and 7 are the primary types to avoid due to their chemical instability and propensity to leach toxins.

The Most Problematic Plastic Bottles to Avoid

When scrutinizing your containers, you will want to be particularly vigilant for plastics marked with codes 3, 6, and 7.

Polyvinyl Chloride (#3 PVC)

Often referred to as the "poison plastic," PVC is one of the most hazardous plastics for human health and the environment. It is used for items like cooking oil bottles, food wrap, and some squeeze bottles. PVC can leach several toxic chemicals, including phthalates. Phthalates are known endocrine disruptors, which can mimic or block hormones and have been linked to reproductive issues, developmental problems, and certain cancers. The manufacturing process for PVC also releases highly toxic dioxins into the environment.

Polystyrene (#6 PS)

Commonly known as Styrofoam, polystyrene is used in disposable cups, food containers, egg cartons, and cutlery. This lightweight and brittle plastic can leach styrene, a chemical that is classified as a possible human carcinogen by the National Institutes of Health. Exposure to styrene has been linked to potential reproductive and developmental problems, as well as nervous system effects. The risk of leaching increases significantly when polystyrene containers are used with hot or oily foods, which are common uses for this material.

Polycarbonate and Other Plastics (#7 OTHER)

The #7 category is a catch-all for various plastics that don't fit into the other six categories. Some #7 plastics, specifically polycarbonates (PC), contain Bisphenol A (BPA). BPA is a well-known endocrine disruptor that can interfere with hormone function and has been linked to a range of health issues, including increased risk of certain cancers, reproductive problems, and developmental issues in children. Although many manufacturers now label products as "BPA-free," some simply substitute BPA with other bisphenols like BPS or BPF, which may have similar endocrine-disrupting effects, making the "safe" claim misleading.

The Critical Role of Heat and Wear

Chemicals can leach from plastic bottles into your beverages, and certain conditions dramatically increase this migration. Heat is a major culprit. Microwaving plastic containers, washing them in a hot dishwasher, or leaving a bottle in a hot car or direct sunlight can cause the plastic's structure to break down, releasing more chemicals. Similarly, normal wear and tear, such as scratching or repeated use, degrades the plastic surface over time, leading to higher rates of chemical leaching. This is particularly problematic for single-use plastics like those marked with a #1 (PET or PETE), which should not be reused for long-term storage or refilling.

Comparison of Common Plastic Bottle Types

To help you visualize the differences, here is a comparison table outlining the key characteristics of various plastic types and their associated risks.


RIC Code	Plastic Type	Common Uses	Primary Health Concerns	Best Practice for Use
1	PET (Polyethylene Terephthalate)	Single-use water and soda bottles	Leaches antimony with heat and reuse	Use once, do not reuse or heat
2	HDPE (High-Density Polyethylene)	Milk jugs, detergent bottles	Generally considered safe	Safe for cold beverages, but reuse with caution
3	PVC (Polyvinyl Chloride)	Cooking oil bottles, food wrap	Phthalates, endocrine disruptors	AVOID food/drink use
4	LDPE (Low-Density Polyethylene)	Squeezable bottles, food wrap	Minimal concerns	Safe for cold beverages
5	PP (Polypropylene)	Bottle caps, yogurt containers	Generally considered safe, high melting point	Safe for hot and cold liquids
6	PS (Polystyrene)	Disposable cups, food containers	Styrene, a potential carcinogen	AVOID food/drink use, especially with heat
7	OTHER (Polycarbonate, BPA)	Reusable sports bottles, baby bottles	Bisphenols (BPA, BPS), hormone disruptors	AVOID if it contains polycarbonate or BPA

Making Safer Choices

To protect your health, reducing your reliance on plastic bottles is the most effective strategy. Opting for non-plastic alternatives is the gold standard for long-term, chemical-free hydration. Look for high-quality, durable bottles made from materials like glass or stainless steel. These materials are chemically stable, easy to clean, and do not leach chemicals into your drinks. For families, especially with infants and children, glass baby bottles are strongly recommended over plastic ones.

Conclusion

Understanding the hidden health risks associated with certain plastics is the first step toward making safer choices for yourself and your family. By avoiding plastic bottles with recycling codes #3, #6, and #7, limiting the reuse of #1 plastics, and switching to glass or stainless steel, you can significantly reduce your exposure to harmful chemicals. Your health is worth the effort of choosing safer hydration options.

For more information on the health impacts of plastics, please visit the National Institute of Environmental Health Sciences website. https://www.niehs.nih.gov/health/topics/agents/endocrine/index.cfm

Frequently Asked Questions

The number inside the triangle is the Resin Identification Code (RIC). It identifies the type of plastic resin used to make the container, and while it's primarily for recycling, it also indicates the potential for chemical leaching. It is wise to pay attention to these codes for health reasons.

Not necessarily. Many 'BPA-free' products use alternative bisphenols, such as BPS or BPF, which some studies suggest may have similar hormone-disrupting effects to BPA. The 'BPA-free' label does not guarantee a product is free of all potentially harmful chemicals.

Heating plastic, whether in a microwave or dishwasher, can cause chemicals within the plastic to break down and leach into your food or drink at a higher rate. It's best to transfer food to a glass or ceramic container before reheating.

The #7 'OTHER' category includes a wide range of plastics. While some are relatively safe, many hard, clear plastics in this category are polycarbonates that contain BPA. It is difficult to know for certain without specific labeling, so it's best to avoid #7 plastics for food and drinks to be safe.

It is not recommended to reuse single-use bottles, which are typically made from #1 PET plastic. They are not designed for repeated use and can break down over time, increasing the chance of chemical leaching, especially with repeated washing or exposure to heat.

For safety and durability, the best alternatives are bottles made from glass or stainless steel. These materials are non-porous, do not leach chemicals, and are easy to clean.

Exposure to chemicals like phthalates, styrene, and BPA from plastics can disrupt the endocrine system, interfere with hormone function, and contribute to reproductive and developmental issues. Some of these chemicals have also been linked to potential cancer risk.