I think it's somewhat more complex than that. Indeed, if one reads the PSL assessments, one finds in fact that the substances do have toxic properties. There are a number of different things that have been classified as toxic through the different definitions in the act, some of which do have what you could consider inherently toxic properties.
When one looks at the assessment of road salt, there are various discussions. The application of road salt can result in deleterious effects on the physical and chemical properties of soil, especially in areas that suffer from poor salt-soil-vegetation management. I have documented damage to vegetation, shifts in plant community structure, behavioural and toxicological impacts, and the associated exposure of mammalian and avian wildlife to road salts.
In that case, in a sense it's perhaps even less complex than the greenhouse gas case. We're dealing with something where the effect is, again, not in its individual organism acute toxicity kind of model, but rather its impact on the global environment.
Indeed, when one looks at Justice La Forest's comments and the majority decision in Hydro-Québec, they're quite clear about the need to be able to accommodate that kind of threat within the definition of toxic. In effect, it attaches a level of warning or a level of concern to these substances, I would argue, in the sense that the consumer response in that context is not necessarily completely unwarranted. It signals the need for caution. It signals that there is a potential for harm here. It signals that there is a need to think about how we're using these substances and how that use might have an impact on the environment and human health.