Priority Substances List Assessment Report for Road Salts

2.0 Summary of Information Critical to Assessment of "Toxic" Under CEPA 1999

Table 1 Physical-chemical properties of road salts ¹
Substance	CAS No.	Specific application	Molecular weight	Eutectic² temperature (°C)	Working³ temperature (°C)	Water solubility (g/100mL) (°C)
Sodium chloride, NaCl	7647-14-5	Road de-icer and anti-icer, de-icing additive for sand	58.44	-21	0 to -15	35.7 (0) 39.12 (100)
Calcium chloride, CaCl₂	10043-52-4	Road de-icer, de-icing additive, anti-icer, suppressant, road construction	110.99	-51.1	<-23	37.1 (0) 42.5 (20)
Mixture of sodium/calcium chloride (80/20 mix)		Road de-icer, road anti-icer		n.a.	-12
Magnesium chloride, MgCl₂	7786-30-3	Road de-icer, de-icing additive, road anti-icer, dust suppressant	95,21	-33.3	-15	54.25 (20) 72.7 (100)
Mixture of sodium/ magnesium chloride (80/20 mix)		Road de-icer		n.a.	<-15
Potassium chloride, KCl	7447-40-7	Alternative road de-icer	74.55	-10.5	-3.89	56.7 (100)
Sodium ferrocyanide, Na₄Fe(CN)₆·10H₂O	13601-19-9	Anti-caking additive	484.07			31.85 (20) 156.5 (98)
Ferric ferrocyanide, Fe₄[Fe(CN)₆]₃	14038-43-8	Anti-caking additive	859,25			insoluble

Physical-chemical properties are from Weast et al. (1989) and Chang et al. (1994).
Eutectic temperature refers to the lowest temperature at which the substance will melt ice.
Working temperature refers to the lowest effective de-icing temperature.