Sanitizer indicator towels are designed to effectively eliminate the risk of cross-contamination & foodborne illness for food service establishments. Yellow towel turns blue when saturated with effective, quat-based sanitizer formula; turns yellow again when sanitizer is depleted. Towels can be recharged again & again. Towel / Wipe Type: Sanitizing Towels; Application: Foodservice; Sanitization; Applicable Material: Hard Nonporous Surfaces; Number of Plies: 1.