5.—(1) For the purposes of this Act a product is defective if it fails to provide the safety which a person is entitled to expect, taking all circumstances into account, including—

(a) the presentation of the product,

(b) the use to which it could reasonably be expected that the product would be put, and

(c) the time when the product was put into circulation.

(2) A product shall not be considered defective for the sole reason that a better product is subsequently put into circulation.