Photographed by Erin Yamagata. Welcome to  Sun Blocked , Refinery29’s global call to action to wake up to the serious dangers of tanning. No lectures or shaming, we promise. Instead, our goal is to arm you with the facts you need to protect your skin to the best of your ability, because there’s no such thing as safe sun.  When cosmetic scientist Dr. Julian Sass first tested Tower 28's new SOS FaceGuard SPF 30 Sunscreen on camera , his disappointment was obvious. Despite the “no white cast” claim prominently displayed on the PR packaging, the sunscreen left a visible gray tinge on his skin. Advertisement ADVERTISEMENT “Marketing this as a no white cast sunscreen in 2025? It just makes me feel so undervalued as a consumer,” Dr. Sass said in the clip. “What frustrates me is that some Black girl is gonna see the advertising about this product and think, Oh my god, they said it had no white cast . And then they're going to end up looking like this.” Dr.…