Table 2. Effect of mono and divalent salt concentrations on the killing efficacy of 20 ppm HSP or H₂O₂ against 10⁶ CFU/mL E. coli K12 at pH 7.

		Percent killing
		Salt concentration (M)
	Salt	0	0.005	0.015	0.025	0.05
HSP	KCl	100	85	76	70	84
	CaCl2	100	58	60	43	45
H2O2	KCl	100	100	94	91	100
	CaCl2	100	100	100	100	100
No Biocide	KCl	0	1	0	3	3
	CaCl2	0	3	5	1	2

All values are normalized to killing in the absence of cations.