For a durable consumption good which turns into waste after consumption, the socially optimal durability increases with an increase in the marginal environmental damage. In a laissez-faire equilibrium under perfect competition, producers fail to provide an efficient product design, i.e. durability is inefficiently small, whereas the amount of solid waste is inefficiently large. The market failure is corrected simply by Pigouvian taxation which also can be interpreted as an extension of the producer responsibility. In the case of imperfect competition (oligopoly or monopoly) Pigouvian taxation indeed ensures an efficient durability but generally not an efficient amount of solid waste.