Porphyria Educational Services
PORPHYRIA EDUCATIONAL SERVICES Bulletin Vol. 1 No. 28 July 11,
1999
FOCUS: Hexachlorobenzene & Glycol Ethers:
More Unsafe Chemical Toxins for Porphyrics
Hexachlorobenzene Hexachlorobenzene is a white crystalline solid.
This compound does not occur naturally. Hexachlorobenzene was
widely used as a pesticide until 1965. It was also used to make
fireworks, ammunition, and synthetic rubber.
It is formed as a by-product during the manufacture of chemicals
use for making solvents, other chlorine-containing compounds, and
pesticides. Small amounts of hexachlorobenzene can also be
produced during combustion processes such as burning of city
wastes. It may also be produced as a by-product in waste streams
of chlor-alkali and wood preserving plants.
There are no current commercial uses of the substance.
Hexachlorobenzene tends to remain as a solid in the environment
for a long Most of it will be in the form of particles clinging
to the bottom and sides of lakes or streams, since it does not
dissolve in water very well. The evaporation of this substance
into the air is not significant under ordinary conditions GLYCOL
ETHERS What are Glycol Ethers?
Glycol ethers are another of the chemical toxins that are harmful
to porphyria patients and are a potential trigger of an acute
porphyric attack.
Glycol ethers are organic solvents. Many different glycol ethers
are used for cleaning. They are often found under the trade names
"Cellosolve" and "Carbitol." Glycol ethers
are volatile organic compounds (VOCs) and may be regulated in
your area. They are also combustible or flammable and must be
handled accordingly.
Glycol ethers are used in the semiconductor industry to strip
photo-resist. They also remove flux, solder paste, inks, greases,
and oils. They are often blended with other solvents for specific
cleaning applications.
The terms E-series and P-series are often used to refer to
ethylene glycol ethers and propylene glycol ethers, respectively.
E-series members generally are more toxic. A semiconductor
industry study has linked two E-series glycol ethers to an
increase in miscarriages among assembly line workers. The two
specific compounds studied were diethylene glycol dimethyl ether
and ethylene glycol monoethyl ether acetate. The time weighted
average (TWA) for ethylene glycol methyl ether acetate is 5 ppm,
but miscarriage increases have been linked to lower exposure
levels.
Glycol ethers tend to emulsify well for cleaning and separate
easily during recovery. One method for disposal is to burn the
solvent in an approved chemical incinerator.