PKW (Purple-K) Dry Chemical Suppressing Agent



WILLIAMS FIRE & HAZARD CONTROL (WILLIAMS) PKW (Purple-K) dry chemical is a potassium bicarbonate-based fire suppressing agent, produced by a proprietary process and very effective against most Class B fires. PKW dry chemical is a free-flowing, water repellent, non-abrasive agent specifically formulated to create a highly-visible, dark violet discharge stream. This visibility assists the firefighter in precisely directing the PKW dry chemical stream (or dual foam/dry chemical stream) for efficient firefighting application.


WILLIAMS PKW dry chemical may be used to combat fires in flammable liquids, gases, and greases (Class B) including such fires when involved with energized electrical equipment (Class C). PKW dry chemical may be readily applied as a single or dual-agent response with the WILLIAMS HYDRO-CHEM nozzle.


WILLIAMS PKW dry chemical has been shown to be four to five times as effective as carbon dioxide-based suppressing agents and more than twice as effective as sodium bicarbonate-based suppressants against Class B fires. PKW dry chemical has been tested at operating temperatures as low as -65 °F (-54 °C) and as high as 120 °F (49 °C).


Do not mix WILLIAMS PKW dry chemical with phosphate-based dry chemicals in a stored container. Use in conjunction with other dry chemical products for immediate incident response is appropriate.

Quality Assurance

WILLIAMS PKW dry chemical is subject to stringent quality controls throughout production, from incoming raw materials inspection to finished product testing, and is manufactured in an ISO 9001:2008 certified facility.

Note: PKW™ contains 2.05% of Purple dye as compared to Ansul’s Standard Purple-K containing 0.0143% of the same dye.

Ordering Information

WILLIAMS PKW dry chemical is available in pails.


Part No. Description Color
423650 50 lb (22.7 kg) Purple