Common Operations and Wet Chemical Methods in Environmental Laboratories - Fundamentals of Environmental Sampling and Analysis - page 136

It is better not to work alone and certainly one should not work alone if the
procedure to be conducted is hazardous.
Remove gloves before leaving the work area and before handling such things
as telephones, doorknobs, writing instruments, and notebooks.
There are three types of fire extinguishers: (a) Water (air-pressurized water)
extinguishers are used for Class A (wood, paper and cloth) fire only. Do not
use water or foam extinguishers for electrical fires. (b) CO 2 extinguishers are
designed for Class B and C (flammable liquid and electrical, respectively).
(c) Dry chemical (powder) extinguishers come in a variety of types which are
always clearly labeled as ABC (for Class A, B and C), BC (for Class B and
C), and D (for Class D fires involving metals such as K, Na, Al, and Mg). Do
not use dry chemical (powder) extinguishers for electronics (instrument) as
they will make clean-up difficult and possibly destroy the electronics. Use
CO 2 extinguishers only in these situations.
6.1.5 Waste Handling and Disposal
Source reduction and waste minimization is always the best strategy before
developing any disposal measures. Source reduction can be achieved simply through
the purchase and use of smaller quantities of chemicals, which can be justified by the
high disposal cost for unused or expired reagents if larger quantities were purchased.
Sometimes a hazardous reagent can be substituted with a non-hazardous chemical or
even eliminated by the use of an alternative procedure.
Have separate containers for general trash, broken glass, and used needles.
Laboratories typically have various containers for other liquid and solid chemical
wastes (inorganic, organic, acid, alkaline, oxidants, etc.). While very dilute liquid
waste can be discharged into laboratory sinks, there are exceptions for certain
chemicals, including concentrated corrosive acids/bases, highly toxic chemicals,
malodorous and lachrymatory chemicals, and other chemical reagents that may
develop potential fire hazard or upset sewage treatment plants.
Special rules apply for certain highly toxic or reactive chemicals, biological
wastes, and radioactive chemicals. Wastes containing PCBs, dioxins, and asbestos
require consultation with federal and state officials before disposal. Peroxides
present special problems in the laboratory because they can be violently reactive or
explosive upon shock, decomposition, and/or reactions with air and water (ACS,
2003). Treat radiochemicals with extreme care and minimize the exposure if at all
possible. Handling radiochemical wastes often requires special training within an
organization. Dilution methods are acceptable for low activity radioactive wastes,
such as ventilation for airborne and flushing into sink for liquid radiochemical
wastes. Biohazard wastes carrying pathogenic microorganisms and virus should be
collected separately in specially marked biohazard bags and autoclaved (121 C,
103 kPa) for a minimum of 30 min prior to disposal. Used pipets should be
disinfected in discard jars by using hypochlorite disinfectants at the highest possible
concentration.