Substitution is a central mechanism in a policy aiming for the elimination of hazardous substances since there are substances that will be problematic to ban. Such are substances considered to be necessary in society, and substances that cause concern but are not hazardous enough to be banned. In this context authorities need to prescribe and promote the development of safer alternatives by applying the Substitution principle.The general intention of the Substitution principle is that a chemical substance must be substituted when a safer alternative is available. This is only common sense. After all, we all try to avoid danger when we can. We don’t walk into a dark alley with a villain standing in the shadows if there is a brightly lit shopping mall in the same direction. We choose the least hazardous alternative. Unfortunately, the logic of commerce is not always in tune with common sense.

Replacing a hazardous substance may be costly or seem unnecessary to the people producing or using it. Also, developing new – less hazardous substance – is resource demanding, and most companies hesitate to take the risk if they aren’t sure that the market will buy the new product. To encourage this, there needs to be an incentive for change. Substitution policies have been effective when used. There are many examples where the use of hazardous substances has been reduced or eliminated by replacing them with easily available substitutes.

Some countries apply this principle in their pesticides policies, prescribing that farmers use the least hazardous substance to achieve their goal. In this way many hazardous pesticides have been phased out and replaced by less hazardous. A chemicals policy aimed at eliminating hazardous substances needs a mechanism to ensure that the hazardous substances deemed necessary by society are substituted as soon as possible.