Safety - Field Sampling: Principles and Practices in Environmental Analysis - page 91

and sulfuric—and the base ammonium hydroxide. When concentrated solutions of these
are opened hydrogen chloride, nitrogen oxides, sulfur oxides, and ammonia gas are
released. Because of this spills of these concentrated acids and bases must be treated with
extreme caution. In addition to the fumes they contain, these acids and bases can react to
release both toxic and flammable fumes. Diluted strong acids and bases often do not have
a strong smell but must still be treated with caution, although they are not as dangerous.
There are many other caustic and/or volatile and flammable liquids and solutions that
can be dangerous and thus must be handled with caution. Organic amines are bases and
have a strong smell of fish. All toxic organic amines must be treated as if they can be
absorbed through the skin, because many of them can. It cannot be guaranteed that
amines will not penetrate rubber or synthetic gloves. (More information about gloves is
given below.) For this and general safety precaution reasons amines should always be
treated with the utmost caution.
Some inorganic and organic liquids and solutions are unusually dangerous. Some, such
as solutions containing hydrides, will spontaneously ignite on exposure to air. Some
organic solvents, such as diethyl ether (often called ether), will ignite if it is dropped on a
hot hotplate. (No spark is necessary.) Under anaerobic conditions methyl mercury may be
produced, which can pass through protective gloves and cause death. There are many
other examples that people doing field sampling need to be aware of. This is why a
history of the field is so important.
4.5.3. Solids
Often solids are easier to deal with because they can simply be picked up, put in
appropriate containers, and then safely handled. There are numerous solid chemicals,
however, that produce dangerous situations. Phosphorus spontaneously ignites and burns
when exposed to air, and the fire is very hard to extinguish. Alkali metals such as sodium
react with water, releasing hydrogen. The reaction is so vigorous that sparks are
produced, setting the hydrogen on fire. Metal hydrides, which can come as solids as well
as the solutions mentioned above, release hydrogen when they become wet and can
produce explosions.
4.5.4. Unknown Materials
Extreme caution in handling any kind of unknown material is always prudent. When
sampling a field it is also always essential to follow all safety precautions because it is
not possible to tell when a sampler, handheld or machine-driven, might encounter and
break open a container of hazardous chemicals. This can happen in an area that
apparently has never had any waste dumped on it and is far from any population center. It
can also happen so quickly that fumes can overcome persons in the area.
Dangers associated with all of the above potential contaminants are compiled in Table
4.4.