Performance standards like PELs have inherent problems such as: Long delays between when a substance is introduced and sufficient data is collected to identify a safe level, the effect of mixtures of chemicals as well as the length of the process to pass a new standard. These lengthly delays can allow workers to be exposed to harmful levels of substances. OSHA is currently looking for alternatives to Performance standards such as the process controls presented in the silica standard. Discuss the advantages and disadvantages to this approach