Dry skin under an ESD wrist strap Cross-section of the skin under a wrist strap. Hydrated skin keeps good contact and charge drains through the strap to ground. Gloves, washing and dry air pull moisture out of the outer layer; dry, cracked skin insulates, and charge has a harder time getting into the strap. SKIN UNDER A WRIST STRAP PHASE 1 · HYDRATED CRACK CROSS-SECTION, NOT TO SCALE Moisture out ↑ Gloves, finger cots, washing anddry air pull it out of the skin. Wrist strap Needs good contact with the skinto carry charge to ground. Dry skin insulates Dry, cracked skin is a poorconductor. Trapped charge Has a harder time getting fromyour skin into the strap. LEGEND Water Charge

Wrist straps and dry skin: R&R Lotion, ESD Control Program Guide: Understanding and Preventing Electrostatic Discharge, white paper (2025), Wrist Straps. Illustration for education only.