Keeping Sunscreen Evidence Valid: Change Control, Lifecycle Testing and Shared Production Lines
An SPF report is a snapshot of one batch, on one day, in one laboratory. Dr Leslie Laquieze explains how to keep evidence valid for the life of a product, and why shared production lines are a point of vulnerability.
By Dr Leslie Laquieze, PharmD, MSc, PhD, MBA, Expert Member, Australian Sunscreen Council
Many sunscreen failures are not failures of the original evidence, but of what happened afterwards: a new supplier, a different emulsifier, a scaled-up process, or a pack that interacts with the formula. Evidence must be kept valid, not just obtained.
The regulator’s view of the lifecycle gap
The Therapeutic Goods Administration’s March 2026 consultation paper on improving sunscreen regulation identifies the problem directly: “After a product’s formulation is scaled up for commercial manufacturing, sponsors typically do not re-test the SPF performance of the final, market-ready batches.” The paper canvasses three options: the status quo; keeping base-formulation testing with guidance on when additional testing is advised, using Statistical Process Control; or mandating SPF testing of the finished product at listing, periodically while the product is in the ARTG, and at the end of its claimed shelf life. It states that “testing the finished product rather than a base formulation confirms that the marketed product delivers the claimed SPF, broad spectrum, and water resistance protection.”
The same paper raises ingredient quality standards, with examples including “particle size distribution for zinc oxide, testing of particle dispersion, or purity for chemical UV filters,” and proposes a review of sunscreen GMP guidance covering critical quality attributes, critical process parameters, and the responsibilities of manufacturers and sponsors for product release. No final decision had been announced as at the date of this article, but the direction is clear.
Sunscreen-specific change control
· Create a sunscreen-specific change assessment covering UV filter grade and supplier, pigments, emollients, polymers, emulsifiers, preservatives, fragrance, propellant, rheology modifiers, packaging and process.
· Define revalidation triggers before launch. An unchanged ingredient (INCI) list does not prove equivalent film formation or photoprotection. A change in the particle size or coating of a mineral filter, or the grade of a chemical UV filter, can alter performance without changing the label.
· Link every pivotal report to the exact formula, batch and pack. Retain samples and stability data where feasible.
· Trend the signals: complaints, adverse events, unexpected sunburn reports, stability drift, out-of-specification results and supplier changes.
· Plan periodic verification proportionate to production volume, claim level, historical variability and use risk.
Stability matters too. On 3 February 2026, the TGA published recalls of all unexpired batches of Banana Boat Baby Zinc Sunscreen Lotion SPF 50+ and Hawaiian Tropic Mineral Zinc Sunscreen Lotion SPF 50+ (nine batches) and of Solar Screen Mineral Zinc Hydrating Face and Body Sunscreen Lotion SPF50+ (two batches), in each case “due to the potential for the lotions to become separated.” The TGA stated that these recalls were “unrelated to the recalls of other sunscreen products following the TGA’s ongoing investigation into Sun Protection Factor (SPF) testing.” The Woolworths recall notice explained that affected products “may appear uneven in texture or show separation of water from the formula, indicating the ingredients may no longer be evenly mixed,” which “can make the sunscreen harder to apply evenly and may reduce the level of sun protection (SPF).”
The stated cause in each case was the physical stability of the lotion, not the zinc oxide filter. The lesson applies to every sunscreen: emulsion integrity and filter dispersion over shelf life are part of performance, and stability results must be linked to the claims they support.
Shared production lines are a point of vulnerability
The recent recalls also show how exposed the market is to weaknesses at the production level. The TGA’s review of sunscreens using the same base formulation as Ultra Violette Lean Screen covered a group of products sold under several brands. When many brands rely on one contract manufacturer, one base formula or one production line, a single weakness can spread across the market.
Shared lines carry a second, less visible risk: cross-contamination. A product can end up containing an ingredient that is not in its formula at all if residues from another product remain on shared tanks, mixers, pipework or filling heads. The PIC/S Aide-Memoire on Cross-Contamination in Shared Facilities (PI 043-1, 1 July 2018), written to guide GMP inspectors, states that “a significant Good Manufacturing Practice (GMP) requirement is that manufacturers pay appropriate attention to those factors that present risks of cross-contamination of the products being manufactured with other materials handled on the site or facility.” Among the primary mechanisms, it lists contamination “originating from inadequately cleaned shared equipment/tool surfaces through failures or inadequate design of cleaning/equipment,” and it asks inspectors whether “the limits for the carryover of product residues [are] established based on toxicological evaluation and justified by risk assessment.”
For sunscreens this is a practical concern. A zinc-only sunscreen made or filled on equipment that also runs products with organic UV filters can pick up traces of filters it was never formulated to contain, unless cleaning between products is validated and verified. That could undermine a claim that specified organic UV filters are absent. If 4-MBC is prohibited, as Option 3 in the TGA’s 2026 Poisons Standard consultation proposes, residues from another product could also put at risk a product that never contained 4-MBC. The same applies to fragrances, preservatives and allergens. None of the February 2026 zinc recalls was attributed to cross-contamination, but the risk is inherent wherever facilities are shared.
Sponsors should:
· obtain each manufacturer’s product changeover matrix and know what else is made on the same equipment;
· require cleaning validation and ongoing cleaning verification, with residue limits for UV filters and other actives justified by risk assessment;
· for mineral-only or ingredient-absence claims, define the claim scope and analytical reporting limit, then use risk-based verification on finished batches where justified;
· consider dedicated or campaign-scheduled equipment for mineral-only products;
· include cross-contamination controls in supplier qualification and audits, and reassess them whenever the manufacturer adds new products or ingredients to a line.
Conclusion
To enter and remain on the Australian market, a company must demonstrate not only that a product obtained a result, but that the result came from the correct method, a competent laboratory, a representative batch and a governance system capable of detecting change. New in-vitro methods improve development and reproducibility and should now be integrated as robustness evidence, while the current Australian legal framework continues to be followed until it is formally amended. Extended and environmental claims remain possible when they are proportionate, supported on the final product and clearly separated from SPF, UVA, broad-spectrum and water-resistance requirements.
Sources
· Therapeutic Goods Administration, “Seeking feedback on improvements to the regulation of sunscreens in Australia”, consultation paper, March 2026: https://consultations.tga.gov.au/tga/improvements-to-regulation-of-sunscreens-in-aus/user_uploads/final---consultation---seeking-feedback-on-improvements-to-the-regulation-of-sunscreens-in-australia---v1-march-2026-2.pdf
· Therapeutic Goods Administration, recall notice, Banana Boat Baby Zinc and Hawaiian Tropic Mineral Zinc Sunscreen Lotion SPF 50+, 3 February 2026: https://www.tga.gov.au/safety/recalls-and-other-market-actions/market-actions/banana-boat-baby-zinc-sunscreen-lotion-spf-50-and-hawaiian-tropic-mineral-zinc-sunscreen-lotion-spf-50
· Therapeutic Goods Administration, recall notice, Solar Screen Mineral Zinc Hydrating Face and Body Sunscreen Lotion SPF50+, 3 February 2026: https://www.tga.gov.au/safety/recalls-and-other-market-actions/market-actions/solar-screen-mineral-zinc-hydrating-face-and-body-sunscreen-lotion-spf50
· Woolworths, product recall notice, Banana Boat Baby Zinc Sun SPF50+ 100g, 3 February 2026: https://www.woolworths.com.au/shop/help/product-recalls/2026-product-recalls/banana-boat-baby-zinc-sun-spf50plus-100g
· Therapeutic Goods Administration, “Sunscreens using the same base formulation as Ultra Violette Lean Screen SPF 50+ sunscreen”: https://www.tga.gov.au/resources/explore-topic/sunscreens/sunscreens-using-same-base-formulation-ultra-violette-lean-screen-spf-50-sunscreen
· Pharmaceutical Inspection Co-operation Scheme (PIC/S), “Aide-Memoire: Cross-Contamination in Shared Facilities”, PI 043-1, 1 July 2018: https://picscheme.org/docview/2270
· Therapeutic Goods Administration, “Advice for sunscreen sponsors and manufacturers”, 23 September 2025: https://www.tga.gov.au/products/medicines/therapeutic-sunscreens/manufacturing/advice-sunscreen-sponsors-and-manufacturers-acceptance-additional-spf-testing-information
· Therapeutic Goods Administration, “Sunscreen ingredients”: https://www.tga.gov.au/resources/explore-topic/sunscreens/sunscreen-ingredients
About the Author
Dr Leslie Laquieze (PharmD, MSc, PhD, MBA) is a pharmacist-scientist and international expert in sunscreen testing, photoprotection, skin pharmacology and dermocosmetic claim substantiation. An expert member of the Australian Sunscreen Council, she has led Kosmoscience Europe since 2018, supporting the evaluation, substantiation and regulatory positioning of cosmetic and dermatological products across international markets.
This article reflects the opinion of Dr Leslie Laquieze. Readers are recommended to seek expert legal advice on all issues discussed.
