Technical information

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Unknown Waste Chemicals
Unknown waste chemicals cannot be accepted for disposal. Disposal contractors cannot accept or ship
unknown waste. It is the responsibility of the Laboratory Supervisor involved to identify all chemicals; this
may require polling laboratory personnel, students, and faculty members to ascertain the owner of such
unknown waste and its identity. Ultimately, it may require the services of an analytical laboratory to
analyze the waste. This can be dangerous particularly when opening containers of unknowns, so it must be
emphasized constantly to laboratory workers to identify and label all waste chemicals and project products
with a chemical name.
Packaging
Waste chemicals must be packaged and containerized in a manner which will allow them to be transported
without danger of spillage, explosion, or escape of dangerous vapors. Wastes which have not been properly
packaged and identified will not be accepted for disposal.
Paperwork
A packing list must be filled out by personnel in the laboratory or department that requests that the waste
picked up by the MIT Safety Office . The packing list must be filled out with the quantity, chemical name,
designation as a solid or liquid, and hazard associated with the waste, i.e., flammable, toxic, water-reactive,
etc. Safety Office personnel will bring the packing list with them when they pick up waste chemicals.
RADIATION SAFETY
A number of acute and long term effects on humans have been related to exposure from various types of
ionizing radiation. Radiation hazards arise when using radio-isotopes, lasers, x-ray generators and plasma
torches. Each is hazardous in a unique way. A thorough knowledge of the device or the isotope that is to be
used is mandatory. The precautions vary widely. Information pertaining to the particular hazard should be
obtained from the facility prior to use, or from the Radiation Protection Office of the Environmental
Medical Services. However, several precautionary procedures should always be followed:
• All work with radioactive material or equipment that produces ionizing radiation must be
registered with the Radiation Protection Office of EMS and performed in accordance with the MIT
Required procedures for Radiation Protection.
• Review with the Radiation Protection Office any potential exposures to non-ionizing radiation
such as ultraviolet, visible, infrared, and microwave radiation.
• Clearly mark areas in which lasers, radiation, and ultraviolet or high intensity light sources are in
use. Standard signs are available from the Radiation Protection Office.
• Wear appropriate eye protection when working with these sources.
• Be aware and alert to radiation hazards when working in or visiting a laboratory where radiation is
generated.
• Class IIIb and class IV lasers require a written Standard (Safe) Operating Procedure (SOP), and
registration with the MIT Radiation Protection Office.
ELECTRICAL DEVICES
Electricity is in constant use both within and outside the laboratory, so it is easy to forget that significant
physical hazard or death may result from its misuse. With direct current, a male can detect a "tingling"
feeling at 1 mA and the median "let-go" threshold (the current at which he cannot release the conductor) is
76 mA. For 60 Hertz alternating current, the values are 0.4 mA and 16 mA respectively. Women are more
sensitive to the effects of electrical current than males; approximately 2/3 of the above currents is needed to
produce the same effect ("Electrical Hazards 5.1," Technical Information, MIT Safety Office). Higher
currents produce respiratory inhibition, then ventricular fibrillation, and ultimately cardiac arrest.
Although minute electrical shocks are generally considered annoying rather than harmful, such shocks
constitute an ominous warning of the presence of potentially hazardous conditions. The device in question
should be disconnected immediately and the cause ascertained by a person competent in such matters.