UL 94

Classifications

• HB: slow burning on a horizontal specimen; burning rate < 76 mm/min for thickness < 3 mm or burning stops before 100 mm
• V-2: burning stops within 30 seconds on a vertical specimen; drips of flaming particles are allowed.
• V-1: burning stops within 30 seconds on a vertical specimen; drips of particles allowed as long as they are not inflamed.
• V-0: burning stops within 10 seconds on a vertical specimen; drips of particles allowed as long as they are not inflamed.
• 5VB: burning stops within 60 seconds on a vertical specimen; no drips allowed; plaque specimens may develop a hole.
• 5VA: burning stops within 60 seconds on a vertical specimen; no drips allowed; plaque specimens may not develop a hole.

  Tests

Foam and films

• HF-2: burning stops within 3 seconds; afterglow less than 30s; burning drips allowed.
• HF-1: burning stops within 2 seconds; afterglow less than 30s; no burning drips allowed.