Sustainable Technologies for Greener Environment : Table 1

Table 1: Cost and risk factors for heat pump antifreeze (Heinonen et al., 1996) [13].
Notes: Ratings- 1 means potential problems and caution required, 2 means minor potential for problems, 3 means little or no potential problems. a) DOWFROST HD; b) GS-4; c) Pure fluid only. Diluted antifreeze (25% solution) is rated 3.

Factor	Antifreeze
	Methanol	Ethanol	Propylene glycol	Potassium Acetate	CMA	Urea
Life cycle cost	3	3	2	2	2	3
Corrosion risk	2	2	3a	2	2	1
Leakage risk	3	2	2a	1b	1	1
Health risk	1	2	3	3	3	3
Fire risk	1a	1c	3	3	3	3
Environmental risk	2	2	3	2	2	3
Risk of future use	1	2	3	2	2	2