Confusion Over “K” Class of Fire Extinguishers Agenda Item 4.2 Kerry Bell PDE – Suppression

1. Confusion Over “K” Class of Fire Extinguishers Agenda Item 4.2 Kerry Bell PDE – Suppression

2. Class K Extinguishers Reported Concern • Potential confusion by plant personnel regarding Class K extinguishers and extinguishers identified as Purple K extinguishers

3. Fire Class Quiz How many different classes of fires are referenced in the 2002 Edition of NFPA 10? • 2 • 3 • 4 • 5 • 6

4. Fire Classes • Class A – Fires in ordinary combustible materials such as wood, cloth, paper, rubber and many plastics. • Class B – Fires in flammable liquids, combustible liquids, petroleum greases and oils, alcohols, flammable gases, etc. • Class C – Fires that involve energized electrical equipment. • Class D – Fires involving combustible metals, such as magnesium, titanium, zirconium, sodium, lithium and potassium. • Class K – Fires in cooking appliances that involve combustible cooking media (vegetable or animal oils and fats).

5. Class K Extinguishers Background • Purple K (potassium bicarbonate) dry chemical extinguishers have been available since the early 1960’s. • Extinguishers containing the Purple K dry chemical have a B:C rating. • The Class K rating was first introduced into 1998 edition of NPFA 10.

6. Label Examples

7. Label Examples

8. Label Examples

9. Label Examples

10. Class K Fire Extinguishers Summary • Jim Roberts requested that UL approach the extinguisher manufacturers and ask their voluntary cooperation to reduce the potential for confusion on this issue.