Pathology chemical, hypochlorite, formaldehyde, Sulphuric acid , sodium citrate,N/10 HCL etc. 

Formaldehyde and xylene are common hazards in histology and pathology laboratories. Occupational and environmental health nurses need to be familiar with the health effects that may result from exposure to these chemicals.
Common chemicals used as clearing agents are Xylene, Toluene, Chloroform, Methyl benzoate and methyl salicylate [8]. Xylene which has a good compatibility with alcohol and paraffin wax has been widely used for the past many years as a clearing agent.