When the substitution of a hazardous chemical agent is not possible in view of the nature of the activity and the risk assessment, the risk is reduced to a minimum by implementing, in order of priority, the following measures:
1° Design of work processes and appropriate technical controls;
2° Use of appropriate equipment and materials so as to avoid or reduce as far as possible the release of hazardous chemical agents into the workplace;
3° Application, at the source of the risk, of effective collective protection measures, such as good ventilation and appropriate work organisation measures;
4° Use, if exposure cannot be reduced by other means, of personal protection measures, including personal protective equipment.