All inbound lots are tested by an accredited third‑party laboratory for heavy metals—including arsenic, cadmium, lead, and mercury. Smith & Truslow upholds standards that exceed industry norms, setting even more stringent maximum thresholds for each metal.

The table below outlines the allowable limits set by the industry compared to the tighter requirements established by Smith & Truslow.

Heavy Metal	Smith & Truslow Specification	Industry Specification
Arsenic	1.0 ppm	1.0 ppm
Cadmium	0.3 ppm	1.0 ppm
Lead	2.0 ppm	3.0 ppm
Mercury	0.1 ppm	1.0 ppm