FBI Handbook of Crime Scene Forensics by Federal Bureau of Investigation Page A

nitroglycerine and nitroglycerine-based dynamite, deteriorate to become chemically unstable. In particular, ether will form peroxides around the mouth of the vessel in which it is stored. All explosive materials are sensitive to heat, shock, and friction.
Pyrophoric materials—such as phosphorus, sodium, and barium—can be liquid or solid and can ignite without an external ignition source in air temperatures less than 130 degrees Fahrenheit (540 degrees Celsius).
Oxidizers—such as nitrates, hydrogen peroxide, and concentrated sulfuric acid—are chemical compounds that readily yield oxygen to promote combustion. Avoid storage with flammable and combustible materials or substances that could rapidly accelerate their decomposition.
Corrosive materials can cause destruction to living tissue or objects such as wood and steel. The amount of damage depends on the concentration and duration of contact.
When working with chemicals, be aware of hazardous properties, disposal techniques, personal protection, packaging and shipping procedures, and emergency preparedness. This awareness comes from appropriate training and the information in a Material Safety Data Sheet. The Material Safety Data Sheet provides information on the hazards of a particular material so that personnel can work safely and responsibly with hazardous materials.
    Light-Source Safety
    When using ultraviolet lights, lasers, and other light sources, personnel must protect their eyes from direct and indirect exposure. 4 Not all laser beams are visible, and irreversible eye damage can result from exposure to direct or indirect light from reflected beams. Prolonged exposure to the skin also should be avoided.
    All personnel in the vicinity of the light source should wear protective eyewear appropriate for the light source. Goggles must have sufficient protective material and fit snugly to prevent light from entering at any angle. The goggles must display the American National Standards Institute’s (ANSI’s) mark denoting eye-protection compliance. Laser-protective eyewear must be of the appropriate optical density to protect against the maximum operating wavelength of the laser source.
    Confined-Space af ty
    A confined space is an enclosed area large enough for personnel to enter and work, but it has limited or restricted means for entry and exit. Confined spaces (e.g., sewers, open pits, tank cars, and vats) are not designed for continuous occupancy. Confined spaces can expose personnel to hazards including toxic gases, explosive or oxygen-deficient atmospheres, electrical dangers, or materials that can engulf personnel entering the space. 5
    Conditions in a confined space must be considered dangerous, and personnel may not enter the space until a confined-space permit has been issued. The atmosphere must be monitored continuously with a calibrated, direct-reading instrument for oxygen, carbon monoxide, flammable gases and vapors, and toxic air contaminants. Periodic readings from these monitors should be documented. Only certified confined-space personnel may operate in confined spaces. Rescue services must be immediately available to the site.
    The following practices must be followed when working in a confined space:
Never enter before all atmospheric, engulfment, mechanical, and electrical hazards have been identified and documented. Isolating hazards must be performed in accordance with OSHA 29 CFR 1910.147, The Control of Hazardous Energy (Lockout/Tagout ). 6
Provide ventilation. Ensure that ventilation equipment does not interfere with entry, exit, or rescue procedures.
Provide barriers to warn unauthorized personnel and to keep entrants safe from external hazards.
Provide constant communication between personnel entering the confined space and attendants.
Ensure that back-up communication is in place prior to entry.
Wear appropriate personal protective equipment, such as self-contained breathing apparatus (SCBA), a full-body harness, head protection, and