ISO 16994:2016 describes methods for the determination of the total sulfur and total chlorine content in solid biofuels. It specifies two methods for decomposition of the fuel and different analytical techniques for the quantification of the elements in the decomposition solutions. The use of automatic equipment is also included in ISO 16994:2016, provided that a validation is carried out as specified and that the performance characteristics are similar to those of the method described in ISO 16994:2016.