744 1-800-452-1261
Flinn Method #4a, continued
2
Without touching the container of picric acid, determine if it has a metal cap. If it
does, do not touch the container at all.
FLINN METHOD
#4b Halogenated Hydrocarbons
Halogenated hydrocarbons require licensed hazardous waste disposal due to
their characteristic toxicity or flammability. Halogenated organic waste should be
segregated from other flammable organic solvents. The best route for disposal
of nonvolatile halogenated hydrocarbons is through incineration. Use a licensed
hazardous waste disposal company as described in Flinn Disposal Method #26c
or #27j.
FLINN METHOD
#4c Organic Acids, Substituted
Substituted organic acids include amino acids and halogenated carboxylic
acid (e.g., chloroacetic acid). Amino acids are nonhazardous, water-soluble and
suitable for landfill or drain disposal using Flinn Disposal Method #26a or #26b.
Water-soluble substituted carboxylic acids and their sodium, potassium, calcium
or magnesium salts can be rinsed down the drain if local sewer discharge limits
permit. See Flinn Disposal Method #26b.
FLINN METHOD
#5 Amines, Aromatic
Aromatic amines are relatively toxic and flammable materials. Common aromatic
amines, such as, pyridine, aniline and diphenylamine,
require licensed hazardous
waste disposal according to Flinn Disposal Method #26c.
Many common dyes and pigments contain aromatic amine groups and do not
present any unusual problems for incineration or burial in a landfill. Please consult
your local regulations and Flinn Disposal Method #26a.
FLINN METHOD
#6 Substances Precipitated by Calcium Ion
Substances in this class include (a) soluble metal salts containing the fluoride ion
and (b) soluble salts containing the oxyanion of a toxic heavy metal (e.g., Mo, W) for
which the calcium salt is quite insoluble. Fluoride ion is highly poisonous.
Do not use procedure for hydrofluoric acid. Hydrofluoric acid is a poison and
extremely dangerous in contact with human flesh. It requires licensed hazardous
waste disposal.
Examples
Sodium fluoride, sodium molybdate, sodium tungstate
Materials Required
Calcium chloride solution, CaCl2, 1 M, in threefold molar excess for disposal of
fluoride or other salts
Hydrochloric acid, HCl, 3 M, or sodium hydroxide, NaOH, 3 M, as necessary to
adjust pH
Funnel, filter paper and flask
Large plastic beaker or similar container (don’t use glass for HF)
pH paper
Wood stirring stick
FLINN METHOD #6 continued on next page.
Procedure
1
Wear chemical splash goggles, chemical-resistant gloves and a lab coat or
chemical-resistant apron.
3
Adjust the pH to 7 using pH indicator paper by adding 3 M sodium hydroxide or
hydrochloric
acid as necessary.
3
A metal-capped container of picric
acid should be handled only by a
trained expert, such as a member
of a bomb squad. Call such an expert
to remove the material from the premises
as soon as possible. (Picric acid
can form salts with the metal in the
cap, and these salts are more explosive
than picric acid itself. The friction
caused in attempting to remove the
metal cap from a container of picric
acid has been reported to cause detonation
of minute amounts of metal
picrate trapped in the threads of the
cap.)
Picric Acid
with Metal Cap
or Dry Picric Acid
4
If—and only if—the container of picric
acid has a plastic cap and contains
visible water, you may proceed.
5
Move the bottle to a fume hood and
immerse the plastic-capped container
upside-down in a beaker of water.
Contact a licensed hazardous waste
disposal company for further instructions
and to remove the material.
Picric
Acid
2
Dissolve the soluble compound (metal
salt) in the smallest amount of water
possible.
4
While stirring, add 1 M calcium chloride
solution in a threefold molar excess to
the neutral solution. Allow the resulting
precipitate
to stand about 15 minutes.
1 M CaCl2