What You Should Know About Plastic Food Storage

Recent research has raised concerns about chemicals in plastic food containers and their potential health effects. Studies show that between 85-100% of the UK population have detectable BPA levels, with phthalates found in virtually all tested individuals. These chemicals have been linked to various health concerns including reproductive issues, metabolic disorders, and developmental effects in children.

The issue centres on chemical additives used to make plastic flexible, durable, and colourful. These aren't chemically bonded to the plastic, so they can migrate into food—especially when exposed to heat, acidic foods, fatty foods, or through repeated use. This article examines what current research tells us about plastic food storage and explores alternatives like platinum silicone, glass, and stainless steel.

BPA and phthalates: the main concerns

The two most studied chemicals in plastic food containers are BPA (bisphenol A) and phthalates. Both are endocrine-disrupting compounds, meaning they can interfere with hormone signalling in the body.

BPA is used in polycarbonate plastics (hard, clear containers) and epoxy resin linings in metal cans. Research has linked BPA exposure to reproductive health issues in both men and women, including effects on fertility and hormone balance. Studies have also found associations with metabolic conditions like obesity and diabetes.

Phthalates are used as plasticisers to make plastics flexible, particularly in PVC plastic wrap and food packaging. Research from 2021-2024 has shown associations between developmental phthalate exposure and cognitive effects in children, including attention and learning difficulties. A 2024 European study found that 100% of 557 tested children had detectable exposure to at least one phthalate.

The concern is particularly acute during pregnancy and early childhood, when hormonal disruption can have lasting developmental effects. These chemicals can potentially affect multiple generations through epigenetic changes.

Links to metabolic health

Research has found associations between plastic chemicals and metabolic health conditions. A January 2024 review of 670 scientific manuscripts found that BPA and phthalates may contribute to obesity through several mechanisms, including effects on fat cell formation and metabolic signalling.

Studies have also linked these chemicals to insulin resistance and type 2 diabetes. The mechanisms appear to involve effects on pancreatic function and insulin sensitivity in tissues.

Regarding regulatory standards: In 2023, the European Food Safety Authority (EFSA) reduced the tolerable daily intake for BPA by a factor of 20,000 to 0.2 nanograms per kilogram of body weight per day. However, the UK Committee on Toxicity rejected this assessment and adopted a limit 1,000 times higher (0.2 µg/kg), citing concerns about EFSA's methodology. This represents a significant regulatory divergence between UK and EU approaches.

European data indicates that 71-100% of populations exceed the stricter EFSA health thresholds for BPA exposure.

Microplastics: physical particles in food

Beyond chemical leaching, research has identified another concern: physical plastic particles breaking off from containers. A 2023 study found that microwaving food in plastic for three minutes released up to 4.22 million microplastic particles and 2.11 billion nanoplastic particles from a single square centimetre of plastic.

The World Health Organisation's 2024 report notes that microplastics have been found in human blood, lungs, liver, and other tissues. A March 2024 study in the New England Journal of Medicine found that patients with microplastics in their artery plaques had a 4.5 times higher risk of heart attack, stroke, or death compared to those without.

Research suggests these particles may trigger inflammatory responses and cellular stress, though more studies are needed to understand the full health implications.

What the recycling codes mean

Many assume certain plastics are safe, but research shows all types release chemicals and particles, especially when heated:

Code #1 (PET/PETE) - Water bottles, single-use containers

  • Releases antimony and acetaldehyde
  • Not designed for reuse or heating

Code #2 (HDPE) - Milk jugs, detergent bottles

  • Generally considered safer but still releases microparticles
  • Releases more chemicals with UV exposure

Code #3 (PVC) - Cling film, some bottles

  • Contains phthalates that migrate into food
  • Avoid for food storage

Code #4 (LDPE) - Plastic bags, squeeze bottles

  • Releases microplastic particles during use

Code #5 (PP) - Yoghurt containers, microwave containers

  • Often marketed as safest plastic
  • Studies show releases millions of microplastic particles, especially when heated

Code #6 (PS) - Takeaway containers, disposable cups

  • Releases styrene (possible carcinogen)
  • Being phased out in many areas

Code #7 (Other) - Mixed plastics, often polycarbonate

  • May contain BPA or BPA alternatives
  • Avoid for food use

The "BPA-free" limitation

Products labelled "BPA-free" often contain replacement chemicals like BPS (bisphenol S) and BPF (bisphenol F). Research shows these alternatives can have similar endocrine-disrupting effects as BPA.

A study testing over 450 BPA-free plastic products found that most still released chemicals with oestrogenic activity. The issue isn't just BPA—it's the broader class of chemicals used in plastic manufacturing.

Other chemicals in plastic

Beyond BPA and phthalates, plastic containers may contain:

  • Antimony - Used in PET plastic production; classified as a probable carcinogen
  • Lead - Found in some plastic stabilisers; particularly concerning for children's development
  • Cadmium - Appears in plastic pigments; classified as carcinogenic
  • PFAS - "Forever chemicals" that persist in the environment
  • Flame retardants - Some types show endocrine-disrupting effects

A 2023 study identified over 30,000 chemicals in plastic food contact materials, with only a fraction adequately tested for safety.

UK consumer guidance

Which?, the UK's leading consumer organisation, provides guidance on reducing plastic exposure based on scientific research. Their recommendations include:

  • Avoid heating plastic containers, even if labelled microwave-safe
  • Replace plastic food storage with glass or stainless steel
  • Don't freeze food in plastic (increases brittleness and particle shedding)
  • Avoid plastic chopping boards

Note: Unlike some international consumer organisations, Which? doesn't currently conduct ongoing laboratory chemical testing for BPA and phthalates in food containers. The most recent UK-specific biomonitoring data is over a decade old, as the UK lacks a continuous national surveillance system.

Economic impact

Endocrine-disrupting chemicals cost the UK an estimated £20-25 billion annually in healthcare costs—roughly equivalent to the entire NHS pharmaceutical budget. This represents about 1.08% of UK GDP or 7% of NHS spending.

These estimates are considered conservative, examining less than 5% of known endocrine-disrupting chemicals.

Understanding recycling

UK plastic packaging achieves a 51-55% recycling rate, though the Big Plastic Count survey found only 17% of household plastic is actually reprocessed into new products. The difference is that industry figures measure plastic collected for recycling (including exports), whilst household surveys measure what's actually reprocessed.

UK recycling by code:

  • #1 PET and #2 HDPE - Widely recycled (92%+ of councils)
  • #3 PVC and #6 PS - NOT widely collected
  • #4 LDPE - Limited collection (supermarket points only)
  • #5 PP - Widely recycled
  • #7 Other - NOT recyclable in normal collections

The UK uses the On-Pack Recycling Label (OPRL) system, becoming mandatory in 2026, which tells you if your local authority collects each item.

Important: Even when plastic is recyclable, it can only be recycled a limited number of times before degrading. Most recycled plastic becomes lower-grade products, not new food containers.

Why platinum silicone is different

Platinum silicone (platinum-cure silicone) is fundamentally different from plastic. Made from silica (sand) rather than petroleum, it's polymerised using platinum as a catalyst.

Key properties:

  • Temperature stable from -50°C to 250°C (freezer to oven safe)
  • No chemical migration at any temperature
  • Free from BPA, phthalates, PVC, lead, PFAS, and other plastic additives
  • Non-porous surface prevents bacterial absorption
  • Dishwasher, microwave, oven, and freezer safe
  • Lasts for years to decades

Certifications to look for:

  • Food Standards Agency approval (UK)
  • LFGB certification (German food safety)
  • ISO 10993 (biocompatibility)
  • USP Class VI (medical-grade)

Choose products explicitly labelled "platinum silicone" or "medical-grade silicone" with proper certifications. Lower-quality silicone using peroxide curing may not offer the same safety profile.

Practical steps to reduce plastic exposure

Start with the highest-risk exposures:

  1. Never microwave food in plastic (regardless of labelling)
  2. Don't store hot foods in plastic—let them cool first
  3. Replace plastic wrap that touches food directly

Make gradual replacements:

  • Glass containers with locking lids for leftovers
  • Stainless steel containers for packed lunches
  • Platinum silicone bags for versatile storage (freezer to oven)

Eliminate the worst plastics:

  • Code #3 (PVC) - Contains phthalates
  • Code #6 (Polystyrene) - Releases styrene
  • Code #7 (Unknown/polycarbonate) - May contain BPA

For children: Children face three times higher exposure per body weight and are more vulnerable during development. Use glass or stainless steel baby bottles, avoid plastic teething toys, and never microwave infant formula or baby food in plastic.

If you must use plastic temporarily:

  • Choose Code #5 (PP) as the least problematic
  • Transfer takeaway food to non-plastic containers quickly
  • Discard scratched, cloudy, or discoloured containers

Summary

Research over the past two decades has identified multiple concerns with plastic food storage containers:

  • Chemical exposure: BPA, phthalates, and other additives can migrate into food, particularly when heated
  • Microplastics: Physical particles break off from containers and enter food
  • Widespread exposure: 85-100% of UK population have detectable BPA levels; phthalates found in virtually everyone tested
  • Regulatory uncertainty: The UK and EU have diverged on BPA safety standards, with debate ongoing about appropriate limits

The limitations of "safer" plastics:

  • All plastic types release some particles and chemicals, especially when heated
  • "BPA-free" products often contain similar chemicals
  • Only 17% of UK household plastic is actually recycled into new products

Alternatives: Glass, stainless steel, and platinum silicone offer stable alternatives that don't release chemicals at any temperature. Whilst more expensive initially, they last significantly longer than plastic.

A practical approach: You don't need to eliminate all plastic immediately. Focus on the highest-risk uses first: heating food, storing hot food, and food storage for children. Gradually replace plastic containers with alternatives as they wear out. The goal is to reduce exposure where it matters most, particularly for pregnant women and young children who are most vulnerable during development.

Back to blog