SPF secrets: Investigating sunscreen | Marketplace

Quick Overview

Marketplace investigation reveals that sunscreen SPF ratings are inconsistent, with products labeled SPF 50 testing as low as SPF 15, and many manufacturers do not retest products when the formula changes, leading to potentially dangerous under-protection.

Key Points: Marketplace tested five SPF 50 sunscreens, finding their actual protection levels ranged from SPF 15 to SPF 60. One product labeled SPF 50 tested at SPF 34, while another tested at SPF 60, indicating significant inconsistency. A mineral sunscreen stick failed to provide full coverage on the face, leaving white patches visible under UV light (14:23). Health Canada does not require companies to retest sunscreens if the formula changes, only if the SPF label changes, which allows products to remain on shelves with potentially inaccurate protection. Dr. Julia Carroll notes that even SPF 30 allows 3% of UVB rays through, and the exact amount applied matters significantly for achieving the labeled protection. The investigation used specialized equipment to measure UV penetration, contrasting the results with the labeled SPF claims.

Context: This Marketplace investigation examines the reliability of sunscreen SPF (Sun Protection Factor) ratings in Canada, questioning whether consumers receive the protection advertised on product labels. The segment features interviews with dermatologist Dr. Julia Carroll and Bryan Eckelfield from AMA Labs, who conducted independent testing on commercially available sunscreens. The investigation highlights that consumers may be applying far less protection than expected, leading to risks like skin cancer, especially for those with darker skin tones or a history of skin cancer.

Detailed Analysis

The Marketplace investigation concludes that SPF ratings on sunscreen sold in Canada are often highly inconsistent, leading consumers to believe they are protected when they are not. Bryan Eckelfield of AMA Labs tested several sunscreens, including one labeled SPF 50, which yielded a laboratory result of only SPF 15. Another product labeled SPF 50 tested at SPF 34, while a third tested at SPF 60, showing wide variability even among products claiming the same protection level. Eckelfield emphasizes that the testing process itself is crucial, comparing results against a control standard. Dr. Julia Carroll, a dermatologist, explains that SPF measures protection against UVB rays (which cause burning) but not UVA rays (which cause aging and cancer), emphasizing the need for 'broad spectrum' coverage. She also notes that people typically apply far less sunscreen than the amount used in lab testing (2 mg/cm²), meaning the actual protection received is much lower than the label suggests. For example, SPF 30 blocks about 97% of UVB rays, leaving 3% exposure, whereas SPF 50 blocks about 98%, leaving 2% exposure; this small difference is critical when application is insufficient. The investigation showed that sunscreen stick formulas were particularly difficult to apply evenly, leaving noticeable gaps under UV light (12:08). Health Canada does not currently require companies to retest products unless the formula changes significantly, leading to concerns that older, untested batches might still be sold with inaccurate, lower protection.