Sun Bum sunscreens are not acutely toxic, and their active ingredients are permitted under U.S. FDA regulations, but “non-toxic” is a marketing term with no regulatory definition, and the safety picture depends heavily on which Sun Bum product you pick up. The brand sells both chemical-filter sunscreens (containing ingredients like avobenzone, octocrylene, and homosalate) and a mineral line (using zinc oxide), and these two categories carry different safety profiles. EWG (Environmental Working Group) ratings for Sun Bum products range widely, from scores as low as 1 (their best rating) for some mineral formulations to 7 or higher for certain chemical-filter sprays. Understanding what drives those differences takes a closer look at what is actually in the bottle.
What EWG Ratings Actually Measure
The EWG’s sunscreen database scores products on a scale of 1 to 10, with 1 being the best and 10 the worst. The score is a composite that weighs several concerns: potential health hazards of individual ingredients, how well the product protects against UVA rays, and whether the labeled SPF is unreasonably high (which EWG considers misleading). A product can score poorly not because any single ingredient is dangerous at the concentration used, but because EWG’s algorithm flags multiple ingredients with theoretical hazard profiles.
Sun Bum’s mineral sunscreens, which rely on zinc oxide as the active filter, generally land in the 1–3 range. Their chemical sunscreens, which use combinations of avobenzone, octocrylene, and homosalate, tend to score in the 4–7 range. This gap exists because EWG penalizes chemical UV filters more heavily than mineral ones, largely on the basis of systemic absorption data and endocrine-disruption concerns. Whether that penalty is proportionate to real-world risk is debated among dermatologists and toxicologists, but the rating disparity is consistent across brands, not unique to Sun Bum.
Chemical UV Filters and Bloodstream Absorption
The ingredient that draws the most scrutiny in Sun Bum’s chemical line is not any single filter but the combination of avobenzone, octocrylene, and homosalate used together. Two FDA-funded clinical trials published in JAMA found that all three of these ingredients, along with octisalate, cross into the bloodstream at levels exceeding the FDA’s threshold of 0.5 ng/mL after standard application. In one trial, homosalate reached average peak plasma concentrations above 20 ng/mL for aerosol sprays, and avobenzone peaked around 4 ng/mL across several formulation types.1JAMA. Effect of Sunscreen Application on Plasma Concentration of Sunscreen Active Ingredients: A Randomized Clinical Trial A separate JAMA trial confirmed that these concentrations accumulated with repeated daily use and persisted through day 7 of the study for most formulations.2JAMA. Effect of Sunscreen Application Under Maximal Use Conditions on Plasma Concentration of Sunscreen Active Ingredients: A Randomized Clinical Trial
What these studies did not show is that absorption at those levels causes harm. The FDA flagged them to trigger further safety testing, not because damage had been demonstrated. The 0.5 ng/mL threshold is a regulatory tripwire that triggers additional studies; it is not a toxicity limit. Still, the absorption data is a major reason EWG downgrades products containing these filters, and it is a legitimate reason to pay attention to the distinction between Sun Bum’s chemical and mineral lines if absorption concerns you.
Do These Filters Act as Hormone Disruptors?
The endocrine-disruption question is where the evidence gets genuinely complicated. A review of organic UV filters found that ingredients including octinoxate, avobenzone, and homosalate may cause disruptions in sex hormones in experimental settings. In human population studies, the observations are sparse, though octinoxate and octocrylene have been linked to hormonal changes in some epidemiological data.3Integrated Environmental Assessment and Management. Occurrence of major organic UV filters in aquatic environments and their endocrine disruption potentials: A mini‐review
However, the concentrations needed to trigger these effects in laboratory assays are far above what shows up in human blood from sunscreen use. A study comparing ToxCast/Tox21 endocrine-activity data against actual human plasma concentrations found that octisalate, homosalate, octocrylene, and avobenzone all had activity thresholds well above real-world blood levels. The activity observed for homosalate in estrogen assays and octocrylene in androgen antagonist assays occurred at concentrations that also triggered general cellular toxicity, suggesting the signal may not reflect a specific hormonal mechanism at all.4Toxicological Sciences. Comparison between endocrine activity assessed using ToxCast/Tox21 database and human plasma concentration of sunscreen active ingredients/UV filters
The European Commission’s Scientific Committee on Consumer Safety has taken a more cautious stance than U.S. regulators. They evaluated oxybenzone and homosalate as having potential endocrine-disrupting properties and recommended maximum concentrations of 2.2% for oxybenzone and 0.5% for homosalate, compared to U.S. limits of 6% and 15% respectively.5PubMed Central. Modernizing U.S. Sunscreen Regulations: How Newer Filters Can Improve Public Health – Section: US Filters Sun Bum’s chemical formulations follow U.S. limits, which means they may contain homosalate at concentrations the EU would not permit. If you want to match European safety thresholds, that is worth checking on the label.
The Octocrylene and Benzophenone Problem
Octocrylene, which appears in many Sun Bum chemical sunscreens, carries a concern that has nothing to do with the ingredient itself but with what it turns into over time. Researchers found that octocrylene degrades into benzophenone, a substance classified as a possible carcinogen, through a chemical process called retro-aldol condensation. In a study of 16 octocrylene-containing sunscreen products, benzophenone was detected in all of them at an average of 39 mg/kg when freshly purchased. After accelerated aging designed to simulate shelf life, the average concentration nearly doubled to 75 mg/kg, with one product reaching 435 mg/kg. Products without octocrylene had no detectable benzophenone.6PubMed. Benzophenone Accumulates over Time from the Degradation of Octocrylene in Commercial Sunscreen Products A separate lab study confirmed that benzophenone concentrations increase in a time- and temperature-dependent manner as octocrylene breaks down.7PubMed. The presence of benzophenone in sunscreens and cosmetics containing the organic UV filter octocrylene: A laboratory study
The practical takeaway here is that using old or heat-exposed sunscreen that contains octocrylene is riskier than using a freshly purchased bottle. If you leave a tube of Sun Bum in your car’s glove compartment all summer and dig it out the following year, the benzophenone levels may be significantly higher than when you bought it. This concern applies to all octocrylene-containing sunscreens, not just Sun Bum.
The Benzene Contamination Episode
In 2021, an independent lab found benzene, a known human carcinogen, in dozens of sunscreen and after-sun products. This was not an ingredient anyone added intentionally; benzene is a manufacturing contaminant, likely introduced through propellant gases used in aerosol sprays. An independent screening published in Environmental Health Perspectives documented the scope of the problem, noting that some aerosol sunscreen products had benzene levels ranging from about 11 to nearly 24 ppm, and several companies issued recalls after the findings became public.8PubMed Central. Independent Sun Care Product Screening for Benzene Contamination – Section: Results and Discussion Sun Bum was not among the brands that issued recalls at that time, but the episode highlighted that aerosol sunscreens as a category carry a contamination risk that lotions and creams do not.
Spray Sunscreens and Inhalation
The format you choose matters beyond the benzene question. Aerosol sprays, which Sun Bum sells extensively, generate small droplets that you can inhale while applying. A study measuring particle size across 78 cosmetic sprays found that propellant-based sprays (the kind with a pressurized can) released an average of about 15% of their particles in the respirable range, meaning small enough to reach the lungs. Pump sprays were much lower, averaging only about 0.5% in that range.9PubMed. Particle size distribution in the evaluation of the inhalation toxicity of cosmetic spray products
For mineral spray sunscreens containing titanium dioxide nanoparticles specifically, a risk-modeling study estimated that even long-term use of spray sunscreen does not pose a significant lung health risk under typical conditions.10PubMed. Estimates of lung burden risk associated with long-term exposure to TiO(2) nanoparticles as a UV-filter in sprays That said, the common-sense advice from dermatologists still holds: spray sunscreen onto your hands and then rub it on your face rather than spraying directly at your head, and apply in well-ventilated areas. For children especially, spraying into the hand first avoids any unnecessary inhalation.
Sun Bum’s Mineral Line and Zinc Oxide Safety
Sun Bum’s mineral products use zinc oxide as the sole active UV filter, which is the ingredient most “clean beauty” advocates prefer. Zinc oxide and titanium dioxide are classified by the FDA as “generally recognized as safe and effective” (GRASE), the only two sunscreen filters to earn that designation under the agency’s ongoing review. They sit on the skin’s surface rather than being absorbed into the bloodstream in meaningful amounts. A large body of research suggests that nanoparticle-sized zinc oxide and titanium dioxide do not penetrate beyond the outermost dead skin layer in intact skin.11PubMed. Nano-sized cosmetic formulations or solid nanoparticles in sunscreens: a risk to human health?
There are some caveats. Nanoparticle forms of these minerals can produce reactive oxygen species when exposed to UV light, a photocatalytic effect that manufacturers address by coating the particles. Silica-based coatings are the most effective at suppressing this, though they cannot completely eliminate it.12PubMed Central. Titanium dioxide and zinc oxide nanoparticles in sunscreens: focus on their safety and effectiveness For practical purposes, this photocatalytic effect is relevant only if the particles penetrate living skin cells, which the weight of evidence says they do not in healthy, intact skin. People with compromised skin barriers, such as those with eczema or open wounds, have a more legitimate reason to be cautious.
Fragrance, Preservatives, and the “Inactive” Ingredients
Sun Bum is known for its banana-coconut scent, and that fragrance is not just branding. It means the product contains fragrance compounds. Among high-SPF broad-spectrum sunscreens sold in the U.S., fragrance was the single most common high-prevalence allergen, found in more than half of products analyzed in one study.13PubMed Central. Potential allergenicity of commonly sold high SPF broad spectrum sunscreens in the United States; from the perspective of patients with autoimmune skin disease – Section: Results That same study identified the chemical UV filters avobenzone, octocrylene, and oxybenzone as the most common low-prevalence allergens. For most people, this is not a problem. But if you have sensitive skin, a history of contact dermatitis, or an autoimmune skin condition like lupus, the fragrance in Sun Bum’s standard line is a genuine concern worth avoiding.
Sun Bum products also typically contain phenoxyethanol as a preservative. According to the European Scientific Committee on Consumer Safety, phenoxyethanol is safe for all consumers, including children of all ages, at concentrations up to 1%. Adverse effects in animal studies were observed only at exposure levels roughly 200 times higher than what consumers encounter in cosmetic products. It is considered one of the most well-tolerated preservatives in cosmetics and is a rare sensitizer.14PubMed. Safety review of phenoxyethanol when used as a preservative in cosmetics A review of formulations across multiple concentration ranges confirmed that phenoxyethanol at concentrations of 0.1% to 1% caused no significant irritation in human tests or in vitro models, though exceeding 1% did increase irritation risk.15Jurnal Pijar MIPA. Effect of the Amount of Phenoxyethanol as a Preservative in Cosmetic Preparations on the Incidence of Skin Irritating Side Effects: A Review This is one area where the “toxic ingredient” alarmism that circulates on social media does not hold up.
The “Reef Friendly” Question
Sun Bum markets some of its mineral products as “reef friendly.” Hawaii’s ban on oxybenzone and octinoxate in sunscreens, which went into effect in 2021, was motivated by research linking those two chemical filters to coral toxicity.16PubMed. Sunscreen bans: Coral reefs and skin cancer Sun Bum’s chemical line does not contain oxybenzone or octinoxate, which technically makes those products compliant with Hawaii’s law. But “reef friendly” is an unregulated marketing term. A market analysis found that about 80% of surveyed sunscreens marketed as “reef safe” or similar contained inorganic (mineral) UV filters, and a wide variety of unregulated claims were being used with no standardized criteria behind them.17Environmental Sciences Europe. Toxic effects of UV filters from sunscreens on coral reefs revisited: regulatory aspects for “reef safe” products
The picture is murkier than any label suggests. A study on physical (mineral) sunscreen and coral found that zinc oxide-based sunscreens still caused growth inhibition in coral and damaged the coral-zooxanthellae symbiotic relationship, primarily through zinc ion toxicity and oxidative stress. Titanium dioxide particles from these sunscreens also showed some toxicity, though less than the zinc component.18PubMed. Are Physical Sunscreens Safe for Marine Life? A Study on a Coral-Zooxanthellae Symbiotic System Meanwhile, a study testing a commercial sunscreen product containing octinoxate and octocrylene found that other ingredients in the formulation increased the bioavailability of these UV filters to corals, making the whole product more toxic than the individual chemicals alone would suggest.19PubMed. Toxicological effects of two organic ultraviolet filters and a related commercial sunscreen product in adult corals No sunscreen currently on the market can honestly claim to be harmless to coral reefs.
Using Sun Bum on Children
Sun Bum sells a “Baby Bum” line designed for infants and toddlers, using mineral filters. Research on infant skin physiology indicates that the skin’s barrier function remains immature through at least the first two years of life, and UV-induced skin changes may begin accumulating as early as the first summer.20American Academy of Pediatrics (Pediatrics). New Insights About Infant and Toddler Skin: Implications for Sun Protection This immature barrier is the reason most pediatric guidelines recommend mineral-only sunscreens for babies and toddlers: zinc oxide and titanium dioxide stay on the skin surface and avoid the systemic absorption that chemical filters produce. Using Sun Bum’s chemical-filter products on very young children would be less advisable than using the mineral Baby Bum line, given the developing skin barrier’s potentially greater permeability.
For older children, the same general guidance applies as for adults. The mineral line minimizes absorption concerns, while the chemical line introduces the same filters whose bloodstream levels the FDA is still evaluating. Fragrance in the original Sun Bum line is also worth considering for kids with eczema or known fragrance sensitivities.
Sunscreen Risk in Context
It is worth stepping back from the ingredient-by-ingredient analysis. An expert consensus from the Skin Cancer Prevention Working Group concluded that the proven benefits of sunscreen for primary skin cancer prevention outweigh the potential and largely hypothetical risks of sunscreen use, especially given the lack of real-world prospective data showing harm from sunscreen ingredients at consumer-use levels.21SKIN The Journal of Cutaneous Medicine. Expert Consensus on Sunscreen for the Primary Prevention of Skin Cancer: Results of the Skin Cancer Prevention Working Group Conference The worst outcome in this space is not using a slightly imperfect sunscreen. It is skipping sun protection entirely because the ingredient list seemed intimidating.
Microplastics and Synthetic Polymers in Sunscreen
One concern that rarely makes the EWG rating but matters to environmentally minded consumers involves the synthetic polymers found in many sunscreen formulations, including some Sun Bum products. Ingredients like dimethicone, acrylates copolymers, and various silicone-based compounds serve as film-formers and skin-feel agents. When washed off in the ocean or down the drain, some of these contribute to micro- and nanoplastic pollution. A review of sunscreen-derived particles in marine environments found that both metallic nanoparticles like zinc oxide and titanium dioxide, and plastic particles, are emerging contaminants in coastal waters. Their concentrations correlated with tourist activity, and at environmentally relevant levels they exhibited toxicity to marine organisms through physical damage and oxidative stress.22Scilight Press. Occurrence and Ecological Risk of Sunscreen-Derived Metallic and Plastic Particles in Marine Environments This is an area where neither chemical nor mineral sunscreens get a clean pass, because the issue is about the full formulation, not just the UV filter.