Factors influencing the effectiveness of warnings
Several other hazard prevention methods are generally preferred over warnings if they can be properly incorporated into a product/task/environment system. Four hazard prevention methods, in their order of preference, are indicated. The first and best defence against injury is to remove or design out the hazard so that users are not exposed to the danger. Substituting a safe chemical for one known to cause injury is one example of hazard removal. Another way to remove a hazard is to ban a dangerous product from being sold, or if the product has already been purchased, to issue a recall to make a retrofit design change or to exchange the product for a better-designed one.