... s (FireWall A ,B) Class A , B Foam Extinguishing Agent Our (FireWall A,B) Class A , B foam extinguishing agents extinguish ... Firewall AB extinguishing agent has been used extensively in Beijing, Shanghai, and numerous other places throughout China and some ... standards and expectations of biodegradability. The Class A , B foam extinguishing agentss micro bubble consistency and its special surfactant ...