Laboratory Standard Operating Procedure for:
Alkali Metals – Li, Na, K
Principal Investigator (PI) Approval is Required Prior to Performing this Procedure
Description
The handling and usage of alkali metals, specifically lithium, sodium, and potassium.
Potential Hazards
Alkali metals react very vigorously with water resulting in the formation of hydrogen gas. This gas can then
spontaneously ignite, causing fires. Additionally, if inhaled, the dust of alkali-metal oxides can cause
damage to the mucous membranes and upper respiratory tracts. Contact of any of these metals with the
skin or eyes may results in burns. Caustic oxides are formed as the metals burn.
Of these three, potassium and the liquid alloy of potassium and sodium are the most reactive, while
lithium is the least reactive.
Engineering Controls
Ensure adequate ventilation.
Work Practice Controls
Use of lithium, sodium, or potassium metal requires proper training and demonstration of correct
technique by an appropriate lab member. The MSDS sheets should also be consulted before first use.
These metals must not be used when working alone.
Lithium, sodium, and potassium metals should only be used in a dry environment away from sparks or any
source of ignition. Good ventilation and access to a dry chemical or dry powder fire extinguisher are also
necessary. The area where the metals will be handled should be free of other chemicals and flammable
objects.
Personal Protective Equipment (PPE)
• Respiratory Protection
Where risk assessment shows air-purifying respirators are appropriate use a full-face particle
respirator type N100 (US) respirator cartridges as a backup to engineering controls. Use respirators
and components tested and approved under appropriate government standards such as NIOSH
(US).
•
Hand Protection
Handle with gloves.
•
Eye Protection
Safety glasses.
•
Skin and Body Protection
A flame-retardant lab coat must be worn while handling these compounds.
•
Hygiene Measures
Handle in accordance with good industrial hygiene and safety practice. Wash hands before breaks
and at the end of workday.
Alkali Metals SOP – 12/2013
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Storage Requirements
• Store in a dry, cool place away from any source of ignition. Store under paraffin oil, mineral oil, or
kerosene. When cutting or weighing out sodium or potassium, they must be kept under hexanes or
toluene as much as possible to prevented them from reaction with the moisture in the air.
•
The container holding the metal must be kept closed, and the amount of material exposed to the
air kept to a minimum. N2 is not an inert gas for lithium, as lithium nitride is formed and can also
react violently with water. Lithium should therefore not be kept under nitrogen for a prolonged
period of time (use Ar instead).
Decontamination
All materials – disposable gloves, wipers, bench paper, etc. - that are contaminated with pyrophoric
chemicals should be disposed as hazardous waste (after appropriate quenching of the compound, see
section 10 of Safety Data Sheet).
Spill Procedures
• EHS&S (509-963-2338 or 2252) and Campus Safety should be called in the event of a large spill or
fire: (Emergencies: 911; Non-emergencies 509-925-8534)
•
DO NOT use water to attempt to extinguish a reactive material fire as it can actually enhance the
combustion.
•
Do not use combustible materials (paper towels) to clean up a spill, as these may increase the risk
of igniting the reactive compound. Soda ash (powdered lime) or dry sand should be used to
completely smother and cover any small spill that occurs.
•
A container of soda ash (powdered lime) or dry sand should be kept within arm’s length when
working with a reactive material.
•
If anyone is exposed, or on fire, smothering the fire is a better course of action than washing with
water because water can fuel the fire.
•
Class D extinguishers are recommended for combustible solid metal fires.
•
Call 9-1-1 for emergency assistance and for assistance with all fires, even if extinguished.
Waste Disposal
After completion of the cutting process, the weigh boat or other weighing container should be rinsed
carefully with a solvent which will react with the excess metal much more slowly than with water (i.e.
methanol, isopropanol).
•
Disposal of Pyrophoric Reagents
Any container with a residue of reactive materials should never be left open to the atmosphere.
Any unused or unwanted reactive materials must be destroyed by transferring the materials to an
appropriate reaction flask for hydrolysis and/or neutralization with adequate cooling.
Training of Personnel
All personnel are required to complete the Chemical Hygiene Plan training. Furthermore, all personnel
shall read and fully adhere to this SOP when handling the chemical.
Alkali Metals SOP – 12/2013
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Certification
I have read and understand the above SOP. I agree to contact my Supervisor or Lab manager if I plan to
modify this procedure.
Name
Principal Investigator
Alkali Metals SOP – 12/2013
Signature
CWU ID #
Date
Revision Date
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