(b) It is hard to be certain in this case. A defendant is liable in negligence for damage of the kind or type that was reasonably foreseeable, but not for damage of a different type that could not have been reasonably foreseen.
In this case Windeyer J said: "Liability for nervous shock depends on foreseeability of nervous shock. That, not some other form of harm, must have been a foreseeable result of the conduct complained of."
This approach provides a sensible limit on the liability of a defendant, but it may be difficult to predict what distinctions between kinds of harm a court will make in a particular case. The exact basis on which kinds of harm are classified is not defined, and depends to some extent on the discretion of the individual judge.
In the case-study, the answer depends on whether a judge finds that the foreseeable harm was 'any harm caused by poisonous chemicals' or, more broadly, 'any harm resulting from contaminated chemicals'.