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Laboratory Safety Tips

There is a safe way to do all jobs

Ask yourself these questions:

  1. What are the worst possible things that could go wrong?
  2. How will I deal with them?

DO NOT perform the tasks or job until you have the answer to these questions. Read labels and educate yourself about the substance by reading the MSDS. There is no substitute for proper work practice and well informed laboratory personnel.

Compressed Gas Cylinders
Why Do I need to Know About Mercury?
Laboratory Audits 

Compressed Gas Cylinders

Compressed gases present both mechanical and physical hazards. If a cylinder valve is accidentally broken, a standard 330 cubic foot cylinder at approximately 2600 psi becomes a rocket attaining speeds of several miles per hour.

The contents of the cylinder may represent additional hazards due to flammability, reactivity, toxicity or asphyxiation. Exposure to corrosive gases such as chlorine, ammonia, and nitrogen dioxide can do irreparable damage to the lungs. Cryogenic gases such as liquid nitrogen can cause tissue damage from extreme cold.

The following list of prudent practices for the safe handling and use of compressed gas cylinders is accordingly presented for your review. Many of the practices have been incorporated into OSHA regulations and are therefore Federal Law.

  1. Insure that cylinder contents are properly labeled. Do not depend on manufacturer color codes!
  2. When transporting a cylinder, insure that the protective cap is in place and securely strap the cylinder to a hand cart. Never drag or slide the cylinder.
  3. Cylinders must be secured firmly at all times. Firmly belt or chain cylinders individually to a wall, cylinder cart, cylinder rack or rigid structure.
  4. Keep incompatible gas classes stored separately. Examples would include separating flammables from reactives, which include oxidizers and corrosives (i.e. oxygen, fluorine, chlorine). Oxygen and nitrous oxide cylinders must be separated from flammables or fuel gas cylinders and combustible materials by a minimum of 20 feet, or by a 5 feet high barrier with a fire rating of at least one half hour. Segregate gas storage from all other chemicals.
  5. Do not expose cylinders to an open flame or to any temperature above 125° Fahrenheit.
  6. Attach the regulator securely before opening the valve. Open cylinder valves slowly. Do not use a wrench to open or close a hand wheel type valve.  If it can not be operated by hand, it should be repaired by the vendor or qualified individuals. Spring loaded pressure relief regulators should be used. When used with hazardous, flammable, or toxic gases, the valve should be vented to the fume hood.
  7. Under NO circumstances should oil or grease be used on regulator valves or cylinder valves. These substances may be reactive with some gases such as oxygen. Regulators used with oxidizing agents must be carefully cleaned to avoid the possibility of explosion due to contact of the gas with any reducing agent or oil.
  8. Never leave cylinder valves open when not in use. Segregate empty cylinders from full. When the cylinder is no longer in use, shut off the valves, relieve the pressure in the gas regulators, remove the regulator and cap the cylinder.
  9. Cylinders should never be emptied to a pressure lower than 170 kpa (25psi) because the residual contents may be contaminated with air if the valve is left open.
  10. If a cylinder leaks and the leak can not be stopped by tightening a valve gland or packing nut, close the leaking valve, replace the valve cap and move the cylinder to a well ventilated area (i.e. outdoors). Tag the cylinder as dangerous, rope the area off, and notify a supervisor.

It is important that you know and understand the properties, uses, and safety precautions of the gas before use. Cylinder safety devices must be maintained in proper operating conditions to function correctly. Only qualified, gas-supplier personnel should service or correct associated problems with cylinders. For further information contact the Department of Environmental Health and Radiation Safety.

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Why Do I need to Know About Mercury?

When you work in an environment contaminated with mercury, you quickly absorb the toxic metal. All forms of mercury are toxic. Mercury poisoning can result from inhalation, ingestion, and injection or absorption through the skin. Elemental mercury poses a health hazard because it is volatile. Elemental mercury, as a vapor, penetrates the central nervous system, where it is ionized and trapped, attributing to its extreme toxic effects. Elemental mercury is not well absorbed by the gastrointestinal tract; therefore, when ingested, it is only mildly toxic. Mercury metal and mercury compounds are highly hazardous if inhaled or if they remain on the skin for more than a short period of time. Dimethyl mercury rapidly penetrates intact skin. Depending on the type of mercury and dose, symptoms may appear relatively quickly or take a number of years to appear.

Listed below are various forms of mercury and their effects and hazards.

  • Mercury vapor (i.e., elemental mercury) is readily absorbed through inhalation and can also pass through intact skin. After absorption, elemental mercury is carried by the blood to the central nervous system where it is oxidized. The oxidation product produces injury. Persons heavily exposed to elemental mercury will develop worsening tremors of the hands, shyness, insomnia, and emotional instability (e.g., the symptoms of the Mad Hatter in Alice in Wonderland--a caricature of hat makers who cured felt in pools of mercury.) Mercury vapors can reach very high levels when the liquid is heated. Such levels will cause adverse effects in humans almost immediately if workplace controls are inadequate. Some equipment, such as thermometers, vacuum pumps, manometer, and sphygmomanometers, may contain mercury.
  • Mercury salts (e.g., mercuric nitrate) are highly toxic and corrosive. They accumulate mostly in the kidney causing renal damage.
  • Organo-mercury compounds attack the nervous system causing tremors, impaired vision and hearing, and paralysis. These compounds may also cause birth defects. The effects from exposure to excessive levels of airborne mercury or skin contact with mercury compounds may not be noticeable for months or years.
  • Mercury fulminate, Hg(ONC) 2, is a detonator used in explosives.
  • Mercury(II) oxide is an oxidizer. It can cause organic materials to start burning in the same manner as any strong oxidizer.
  • Dimethyl mercury, an extremely toxic material, is a colorless, sweet-smelling liquid. It is a severe fire hazard, with a flash point of -4°C. This material rapidly penetrates the skin resulting in severe exposure from very minor quantities, which can be fatal. Extreme caution is required when working with this material and when selecting personal protective equipment (PPE).

When a mercury spill occurs, please contact Environmental Health and Radiation Safety Office at X48749.

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Links
http://www.ilpi.com/safety/mercury.html
http://www.osha.gov/SLTC/healthguidelines/mercuryvapor/recognition.html
http://www.atsdr.cdc.gov/tfacts46.html
http://www.mercurysafety.co.uk/hlthinfo.htm
http://www.minerals.csiro.au/safety/mercury.htm
http://www.llnl.gov/es_and_h/hsm/doc_14.05/doc14-05.html#2.0

Laboratory Audits 

Safety audits are essential and basic tool for establishing and maintaining safe conditions and finding unsafe practices in the workplace. Safety audits are a practical ways to identify and correct unsafe conditions. Environmental Health and Safety Office perform safety audits biannually. Each time a laboratory is audited, a report will be sent to Principle Investigator and a follow- up audit will be conducted by the Laboratory Safety Officer to ensure that efforts were made to correct problem stated in the audit.

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