Page 247 - Demo

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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.
Chemical Disposal Procedures
245
FLINN METHOD
3
Picric Acid with Metal Cap or Dry Picric Acid
#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
Large plastic beaker or similar container (don’t use glass for HF) Wood stirring stick
Hydrochloric acid, HCl, 3 M or sodium hydroxide, NaOH, 3 M as
necessary to adjust pH
pH paper
Funnel, filter paper and flask
Procedure
1
Wear chemical splash goggles, chemical-resistant gloves, and a lab coat or chemical-resistant apron.
2
Dissolve the soluble compound (metal salt) in the smallest amount of water possible.
3
Adjust the pH to 7 using pH indicator paper by adding 3 M sodium hydroxide or hydrochloric acid as necessary.
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.)
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 haz- ardous waste disposal company for further instructions and to remove the material.
#4b Halogenated Hydrocarbons
Picric Acid
FLINN METHOD
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.
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.
1M CaCl2
FLINN METHOD #6 continued on next page.
FLINN METHOD
#4c Organic Acids, Substituted
Substituted organic acids include amino acids and halogenated carbox- ylic 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 dipheny- lamine, 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.