Chemical Safety Peter Yeung D.G. Manager Safety Office The University of Hong Kong
Lesson Learned 1. Laboratory fire 2. Chemical spill 3. Incompatibles in waste disposal
Lab. Fire
Sodium/Solvent
Chemical Spill
Incompatibles in Waste Disposal
Hazardous Materials Flammables Oxidizers Corrosive Toxic Substances Carcinogens Spontaneously Ignitable Materials (Pyrophoric)
Working safely with flammables V Ventilation I Ignition C Containment E Exchange S Seperation Think V I C E S
Oxidizers React vigorously with organic solvents, eg. Nitric acid, Perchloric acid Hydrogen peroxide Chlorates, Nitrates
Some common solvents Solvents FP o C TLV-TWA ppm acetic acid 39 10 acetone -18 250 acetonitrile 5.6 20 diethyl ether - 45 400 ethanol 13 1000 ethyl acetate - 4.4 400 methanol 11 200 n-pentane - 49 120 toluene 4.4 100
Warning Signs
Material Safety Data Sheets (MSDS) Available in hku library webpage Sigma-Aldrich MSDS e- resources Also in website of chemical supplier, e.g. Fisher, Baker, Merck Visit website of Safety Office http://www.hku.hk/safety/
Incompatible Chemicals (Chemical Safety Manual) Appendix I: Table 1 Partial List of Incompatible Chemicals (Reactive Hazards) Acetic acid Chromic acid, nitric acid, peroxides, and permanganates. Acetic anhydride Hydroxyl-containing compounds, ethylene glycol, perchloric acid. Acetone Concentrated nitric and sulfuric acid mixtures, hydrogen peroxide. Acetylene Chlorine, bromine, copper, silver, fluorine, and mercury. Table 2 Partial List of Incompatible Chemicals (Toxic Hazards) Arsenical materials Any reducing agent* Arsine Azides Acids Hydrogen azide Cyanides Acids Hydrogen cyanide Hypochlorites Acids Chlorine or hypochlorous acid
Routes of Contamination Inhalation Ingestion Absorption Injection (broken glassware)
Transport of Chemical Use Goods Lift as far as possible Place in suitable Carrier Within Laboratory Use Both Hands, one on the neck and the other at the bottom
Hierarchy of Control Substitution(1st choice) Engineering Control Administrative Control Personal Protective Equipment PPE (last line of defence)
Engineering Control Local Exhaust Fumehood Emergency Exhaust
Administrative Control Safety Station Solvent Cabinet
PPE: Eye Protection Visor Nitrile Glove Cryo-glove
Compressed Gas Cylinder Know the Properties Kept Fastened Use Trolley Use Regulator & Flow Control Valve
Liquid Nitrogen Asphyxiation Cryogenic Burn, -196 o C Pressurization, expand 700 times Cryovial Vacuum Line
Poor Housekeeping leads to Hinder Escape Route Chemical Contamination Cuts Tripping Slipping
Emergency Response in Chemical Spill Attend the injured and remove them to safe place Alert others to evacuate Call emergency no. Close door Assist emergency personnel Remember A A C C A
How Safety Office can help Bulk purchase of chemicals Provision of central supply solvents & liquid nitrogen Provision of labels, safety glasses Provision of spill response kit, spill catcher tray & waste pails Provide guidance on safe use of chemicals & waste disposal Advise and assist in event of a chemical emergency
Summary Identify the hazards & assess the risks Minimizing exposure to chemicals by using fumehood and PPE Good housekeeping Safe transport of chemicals Segregate wastes in disposal of chemicals Know the response to accident & emergency