Metals and Can‑Liner Migration in THC/CBD Beverages: 2025 Testing Plans to Prevent Recalls

Why can liners are becoming a 2025–2026 compliance flashpoint for infused drinks

Across the U.S., the dispensary rollout of infused drinks has accelerated—and with it, scrutiny is shifting from “traditional” contamination (microbials, pesticides, residual solvents) toward packaging–product interactions that can change a drink over time.

Two risk categories are converging:

• Elemental (metal) migration and corrosion-related defects driven by acidic formulas, salts, chelators, and surfactants.
• Potency drift and emulsion instability unique to infused beverages (especially nanoemulsions), which can be exacerbated by contact with can coatings and seams over shelf life.

In other words, a beverage can pass release testing on day 0 and still become a recall candidate by day 60.

State regulators haven’t issued one unified national standard for can-liner migration in infused beverages, but enforcement trends show rising expectations for documented stability, traceability, and preventive controls. California’s regulator, for example, has publicly posted beverage recalls tied to packaging safety issues (a signal that packaging failures are already on the radar). See California’s official recall archive for examples of beverage-related actions: https://www.cannabis.ca.gov/consumers/cannabis-recalls-and-safety-notices/cannabis-recalls-archive/

Separately, mainstream beverage recalls for metal fragments/foreign material keep the broader category sensitive, and that sensitivity carries into infused drink oversight. Example consumer-facing recall coverage: https://www.today.com/food/recall/coca-cola-recall-2025-rcna239130

This post lays out a practical, audit-ready THC beverage can liner migration testing 2025 plan designed to reduce recall risk—particularly for acidic, surfactant-rich nanoemulsions.

Informational only. This is not legal advice and not a substitute for state-specific regulatory counsel or qualified laboratory/packaging engineering guidance.

The science problem: why acidic nanoemulsions can stress “standard” beverage cans

Three mechanisms that matter in real-world canning

1) Corrosion and metal exposure at vulnerable points

Even with modern aluminum cans, risk can concentrate at seams, scored openings, and any areas where coating coverage is imperfect. Low pH, chloride salts, and certain acids can increase corrosion potential—especially over warm storage.

2) Coating/liner interaction with surfactants and solvents

Nanoemulsions often rely on emulsifiers, surfactants, and solubilizers that can behave like “cleaners” against coatings over time. This may contribute to:

• Off-flavors/taints
• Haze or emulsion breakdown
• Increased extractables/leachables from the liner (including NIAS—non-intentionally added substances)

3) Potency drift and adsorption

Some formulations experience potency loss or distribution changes where actives partition into the liner or accumulate at the container interface. This complicates compliance because many states regulate potency with tolerance bands, and enforcement can occur after products have sat in retail.

A useful industry signal of this issue: reporting has highlighted that liner interactions can degrade potency over time in canned infused drinks. Example coverage: https://kstp.com/kstp-news/top-news/thc-beverage-makers-adapt-to-canning-quirk-that-degrades-potency/

What regulators and auditors expect in 2025: “prove it over shelf life” documentation

Expect more questions during inspections and from co-packers/retail buyers

Even where state rules focus primarily on contaminant panels and labeling, inspectors and buyers increasingly ask for:

• Stability evidence supporting shelf-life and labeled potency
• Packaging specifications (including liner chemistry statements)
• Complaint trending and CAPA documentation
• Rapid lot trace + hold/release controls

This is consistent with the broader food and packaging compliance environment where documentation, preventive controls, and chemical hazard management are emphasized.

Example of tightening metals oversight: Washington’s metals testing rulemaking signals

While Washington’s action is not beverage-can-specific, it’s a strong indicator of momentum toward broader metals risk control expectations. In June 2025, WSLCB announced rulemaking activity to consider expanding metals testing requirements (CR-101). Source: https://content.govdelivery.com/accounts/WALCB/bulletins/3e6b1e7

For beverage brands planning multistate expansion, this matters because your strictest state often becomes your national QA baseline.

A 2025 packaging safety plan for infused beverages in cans (accelerated + real-time)

The goal is to build a packaging validation program that stands up to:

• state inspections,
• distributor/retailer onboarding,
• co-packer qualification,
• and worst of all, post-market complaints.

Below is an actionable plan you can adapt.

Step 1: Define your packaging “design space” and lock the bill of materials

Before testing, document exactly what you are testing.

At minimum, create a controlled specification that includes:

• Can manufacturer, plant, and can size (don’t assume 12 oz and 16 oz behave the same)
• End/closure supplier (lids can differ from body)
• Liner/coating system (epoxy vs BPA-NI alternatives; supplier trade name; revision)
• Seam parameters (target seam thickness/overlap/inspection method)
• Any contact materials in the line (gaskets, hoses, filler bowls)

Build into your procurement and change control: no liner chemistry changes without requalification.

Step 2: Use a two-track study: accelerated screening + real-time confirmation

Accelerated study (screening)

Use accelerated conditions to quickly identify “bad pairings” of formula and liner.

Common approaches include elevated temperature storage (e.g., 30–40°C) and light exposure if relevant. Your exact protocol should be justified scientifically and aligned with how the product is distributed.

Measure at minimum:

• pH and titratable acidity
• visual stability (phase separation, haze)
• potency (total/active analytes per state definitions)
• homogeneity (can-to-can variation; top/middle/bottom within-container checks if feasible)
• metals screening (see Step 3)
• sensory/off-flavor checks (trained internal panel + documented criteria)

Real-time study (confirmation)

Run the product under intended storage conditions and your actual shelf life.

Minimum checkpoints many programs adopt:

• Open (day 0 / release)
• 30 days
• 60 days
• 90 days

Continue to end-of-shelf-life and, ideally, add a short post-shelf-life abuse window (e.g., +30 days) if your distribution chain is imperfect.

Step 3: Add ICP‑MS metals screening designed for packaging interaction (not just ingredient contamination)

Most infused product metals testing programs focus on ingredient contamination. For cans, you also want to detect whether storage increases metals.

What to test

Work with an ISO/IEC 17025-accredited laboratory that can run ICP‑MS and can validate your beverage matrix.

At a minimum, screen for the “usual suspect” toxic elements that many state programs already emphasize (commonly including lead, cadmium, arsenic, mercury). Then add packaging-relevant elements often associated with alloys, coatings, inks, or process equipment contact, such as aluminum, tin, nickel, chromium, and others as justified by your materials.

Even if your state panel doesn’t require all of these, trending them over time is valuable for early warning.

How to structure the study

• Test day 0 product (baseline).
• Test the same lot at 30/60/90 (and end of shelf life).
• Include a glass control (same beverage filled into inert glass) to distinguish packaging-driven changes from formula-driven drift.
• Consider replicate cans from different production times within the run (start/middle/end) to capture line variability.

Why ICP‑MS specifically

ICP‑MS is widely used for trace elemental analysis and can achieve low detection limits appropriate for risk management in ingestibles.

While USP <232>/<233> are pharmaceutical chapters, they’re frequently referenced as a framework for elemental impurities control and analytical procedures. FDA has also issued guidance connecting elemental impurity control to these frameworks for drug products (useful as an analytical reference point, not a direct beverage rule). See FDA PDF: https://www.fda.gov/media/98847/download

Step 4: Run migration/extractables work on liners—especially if you claim “BPA-free”

Don’t treat “BPA‑NI” as “migration‑proof”

The market shift away from BPA-based epoxy systems has increased focus on alternative chemistries, and globally there is heightened attention on bisphenols in food contact materials.

For perspective, the EU adopted Commission Regulation (EU) 2024/3190 addressing BPA and other bisphenols in certain food-contact materials, including transitional periods (not U.S. law, but it influences supplier documentation and retailer expectations). Commentary summarizing the regulation and transition windows: https://www.hoganlovells.com/en/publications/eu-bans-bpa-in-food-contact-materials-what-does-it-mean-for-industry

If you are using alternative liners, you should obtain from suppliers:

• a food-contact compliance statement for intended use,
• information about coating chemistry family and any use limitations,
• and change notification commitments.

What to test

Migration testing is typically performed with food simulants or product itself, depending on your test plan, and should include:

• targeted analytes of concern (based on liner chemistry), and
• untargeted screening where feasible to capture NIAS risk.

The practical business goal is not academic perfection—it’s to define acceptance criteria and a requalification trigger that prevents surprises.

Step 5: Potency and homogeneity checks that match beverage realities (not gummy assumptions)

Infused drinks aren’t uniform solids; they’re dispersions that can separate subtly.

Use beverage-appropriate method expectations

AOAC has published consensus performance requirements relevant to infused beverage matrices, including beverage sample preparation considerations and heavy metals in beverage matrices.

Examples:

• AOAC SMPR 2023.001 (sample preparation considerations for beverage matrices): https://www.aoac.org/wp-content/uploads/2023/11/SMPR-2023_001-1.pdf
• AOAC SMPR 2023.005 (heavy metals in cannabis-containing beverages): https://www.aoac.org/wp-content/uploads/2023/12/SMPR-2023_005-1.pdf

Even if you are not “AOAC official method” compliant, aligning your internal validation and lab selection to these expectations strengthens defensibility.

Suggested minimum homogeneity design

For each checkpoint (open/30/60/90):

• Pull multiple cans across the lot.
• For at least some samples, evaluate within-can distribution (e.g., after standard inversion protocol vs no inversion).
• Document a standard “consumer-like” mixing instruction and match it in your test method.

Step 6: Cleaning-in-place (CIP) verification for canning lines—treat it as a chemical hazard control

When you’re investigating metals or off-flavors, the can isn’t always the culprit. Canning lines can contribute residues (cleaners/sanitizers), carryover flavors, and metal ions from worn parts.

Your packaging safety plan should include:

• CIP validation (evidence the procedure works)
• CIP verification (evidence it worked this time)
• documented acceptance criteria (e.g., conductivity rinse endpoints, ATP swabs where appropriate, visual inspection requirements)

Even in the broader food world, preventive controls guidance emphasizes monitoring, verification, and recordkeeping as a core expectation. If you operate under a co-packer’s SQF/BRCGS program, these elements are typically standard.

Step 7: Put packaging acceptance criteria inside co‑packer QSAs (quality agreements)

If you use a co-packer, your Quality/Supply Agreement should clearly define:

• who controls can/liner supplier selection
• required certificates of compliance and change notices
• incoming packaging inspection steps (including seam checks and visual liner defects)
• hold-and-release authority if stability or metals trends go out of spec
• retain sample requirements (how many, where stored, for how long)

The biggest operational failure mode is ambiguity—especially when complaints hit.

How to set practical acceptance criteria (so you can actually stop a recall)

Acceptance criteria should be set using:

• state potency tolerance rules where you sell,
• your internal risk tolerance,
• and the reality of analytical variability.

Suggested criteria categories to document

• Metals: “no statistically significant increase” vs baseline and below applicable action limits; include investigation triggers for upward trends even if still below limits.
• Potency: within your labeled spec throughout shelf life; define “alert” and “action” bands.
• Sensory: define off-flavor descriptors and rejection thresholds.
• Physical stability: no persistent phase separation; haze thresholds if relevant; carbonation retention for sparkling products.
• Container integrity: seam and leak criteria; corrosion/pitting visual rejection criteria.

Rapid containment: lot trace, holds, and investigation playbooks

When an out-of-spec result appears at day 60, the difference between a small correction and a brand-damaging recall is speed.

Build a playbook that includes:

• Lot trace in ≤ 2 hours (finished goods → packaging lots → ingredient lots → production shift)
• Immediate hold procedures for in-market inventory (warehouse, distributor, retail)
• Decision tree for re-test vs confirmatory testing vs recall notification
• Root cause workflow (liner change, seam issue, CIP deviation, ingredient pH drift, emulsifier swap)
• CAPA with effectiveness checks

California’s public recall postings show that enforcement is not theoretical; actions become public and can expand quickly if documentation is weak. Recall archive: https://www.cannabis.ca.gov/consumers/cannabis-recalls-and-safety-notices/cannabis-recalls-archive/

What this means for businesses and for consumers

For manufacturers and brand owners

• Treat can selection and liner chemistry as a critical control decision, not a purchasing detail.
• In 2025, shelf-life proof is increasingly a gate for distribution: expect buyers to ask for stability and packaging interaction documentation.
• Build your program around accelerated + real-time data, not just day-0 COAs.
• Write your co-packer agreements so that packaging changes trigger requalification.

For retailers and distributors

• Ask for a packaging validation summary, not only a release COA.
• Verify the supplier has a documented hold-and-trace process and retain samples.

For consumers

• Store beverages as directed and avoid extended heat exposure.
• If a product tastes “metallic,” unusually bitter, or shows separation beyond what the label describes, stop use and contact the retailer/manufacturer.

Key takeaways (2025 action list)

• Run ICP‑MS metals trending over shelf life (day 0/30/60/90/end), not just a single compliance snapshot.
• Validate liner compatibility with acidic, surfactant-rich nanoemulsions using accelerated screening plus real-time confirmation.
• Test potency + homogeneity over time using beverage-appropriate methods and documented mixing protocols.
• Verify CIP and document it as part of your chemical hazard controls.
• Embed packaging acceptance criteria in QSAs and enforce change-notification controls.
• Build rapid hold/trace procedures so you can contain issues before they escalate.

Next step: make your packaging validation audit-ready

If you’re building or updating a beverage compliance program for 2025–2026, CannabisRegulations.ai can help you operationalize a packaging safety plan—study design, documentation templates, co-packer QSA clauses, and state-by-state compliance alignment—so you’re ready for inspections, retailer audits, and rapid scale.

Get support at https://www.cannabisregulations.ai/