Acetone
Acetone (also known as propanone, dimethyl ketone, 2-propanone, propan-2-one,
dimethylformaldehyde and β-ketopropane) is a colorless, mobile, flammable liquid. It
is the simplest example of the ketones. Acetone is miscible with water, ethanol, ether,
etc., and itself serves as an important solvent. The most familiar household uses of
acetone are as the active ingredient in nail polish remover and to thin some paints.
Acetone is also used to make plastic, fibers, drugs, and other chemicals. In addition to
being manufactured as a chemical, acetone is also found naturally in the environment,
including in small amounts in the human body.
Acetone is believed to exhibit only slight toxicity in normal use, and there is no strong
evidence of chronic health effects if basic precautions are followed.
At very high vapor concentrations, acetone is irritating and, like many other solvents,
may depress central nervous system. It is also a severe irritant on contact with eyes,
and a potential pulmonary aspiration risk. In one documented case, ingestion of a
substantial amount of acetone led to systemic toxicity, although the patient eventually
fully recovered. Some sources estimate LD50 for human ingestion at 1.159 g/kg; LD50
inhalation by mice is given as 44g per cubic meter, over 4 hours.
Antimony
Antimony is a chemical element with the symbol Sb and atomic number 51. A
metalloid, antimony has four allotropic forms. The stable form of antimony is a bluewhite metalloid. Yellow and black antimony are unstable non-metals. Antimony is
used in flame-proofing, paints, ceramics, enamels, a wide variety of alloys,
electronics, and rubber.
Antimony and many of its compounds are toxic. Clinically, antimony poisoning is
very similar to arsenic poisoning. In small doses, antimony causes headache,
dizziness, and depression. Larger doses cause violent and frequent vomiting, and will
lead to death in a few days.
Arsenic
Arsenic is a chemical element that has the symbol As and atomic number 33.
It is used in:
Wood preservation: The toxicity of arsenic to insects, bacteria and fungi makes it an
ideal component for the preservation of wood.
Pigments: Copper acetoarsenite was used as a green pigment known under many
different names, including 'Paris Green' and 'Emerald Green'. It caused numerous
arsenic poisonings.
Military: Lewisite; a chemical weapon, acting as a vesicant (blister agent) and lung
irritant. Up to 2% of arsenic is used in lead alloys for lead shots and bullets
Arsenic and many of its compounds are especially potent poisons. Arsenic disrupts
ATP production through several mechanisms. At the level of the citric acid cycle,
arsenic inhibits pyruvate dehydrogenase and by competing with phosphate it
uncouples oxidative phosphorylation, thus inhibiting energy-linked reduction of
NAD+, mitochondrial respiration, and ATP synthesis.
Arsenicosis: chronic arsenic poisoning from drinking water
Chronic arsenic poisoning results from drinking water with high levels of arsenic over
a long period of time. Effects include changes in skin color, formation of hard patches
on the skin, skin cancer, lung cancer, cancer of the kidney and bladder, and can lead
to gangrene.
Arsine
Arsine is the chemical compound with the formula AsH3
AsH3 is used in the synthesis of semiconducting materials related to microelectronics
and solid-state lasers.
AsH3 was proposed as a possible chemical warfare weapon. Arsine was never
officially used as a weapon, because of its high flammability and its lower efficacy
when compared to the non-flammable alternative phosgene. On the other hand,
several organic compounds based on arsine, such as lewisite (βchlorovinyldichloroarsine), adamsite (diphenylaminechloroarsine), Clark I
(diphenylchloroarsine) and Clark II (diphenylcyanoarsine) have been effectively
developed for use in chemical warfare.
The toxicity of arsine is distinct from that of other arsenic compounds. The main route
of exposure is by inhalation, although poisoning after skin contact has also been
described. Arsine attacks haemoglobin in the red blood cells, causing them to be
destroyed by the body.
Barium
Barium is a chemical element. It has the symbol Ba, and atomic number 56.
Barium compounds, and especially barite (BaSO4), are extremely important to the
petroleum industry. Barite is used in drilling mud, a weighting agent in drilling new
oil wells.
Barium carbonate is a useful rat poison.
Barium oxide is used in a coating for the electrodes of fluorescent lamps, which
facilitates the release of electrons.
Barium carbonate is used in glassmaking.
Barite is used extensively in rubber production.
Barium nitrate and chlorate give green colors in fireworks.
All water or acid soluble barium compounds are extremely poisonous. At low doses,
barium acts as a muscle stimulant, while higher doses affect the nervous system,
causing cardiac irregularities, tremors, weakness, anxiety, dyspnea and paralysis. This
may be due to its ability to block potassium ion channels which are critical to the
proper function of the nervous system.
Benzene
Benzene, or benzol, is an organic chemical compound and a known carcinogen with
the molecular formula C6H6.
As a gasoline (petrol) additive, benzene increases the octane rating and reduces
knocking. European petrol specifications now contain 1% limit on benzene content.
The United States Environmental Protection Agency has new regulations that will
lower the benzene content in gasoline to 0.62% in 2011.
Today benzene is mainly used as an intermediate to make other chemicals. Smaller
amounts of benzene are used to make some types of rubbers, lubricants, dyes,
detergents, drugs, explosives, napalm and pesticides.
The major effects of benzene are chronic (long-term) exposure through the blood.
Benzene damages the bone marrow and can cause a decrease in red blood cells,
leading to anemia. It can also cause excessive bleeding and depress the immune
system, increasing the chance of infection. Benzene causes leukemia and is associated
with other blood cancers and pre-cancers of the blood.
Beryllium
Beryllium is a chemical element with the symbol Be and atomic number 4.
Beryllium metal is used in the defense and aerospace industries as light-weight
structural materials in high-speed aircraft, missiles.
Beryllium-copper alloys are used in making of spot-welding electrodes, springs, nonsparking tools and electrical contacts.
Thin sheets of beryllium foil are used as windows in X-ray detectors to filter out
visible light and allow only X-rays to be detected.
Beryllium is used in nuclear weapon designs as the outer layer of the pit of the
primary stage, surrounding the fissile material. It is a good pusher for implosion, and
the best possible neutron reflector, as in Beryllium moderated reactors.
Long term exposure to beryllium can increase the risk of developing lung cancer. The
more common and serious health hazard from beryllium today is chronic beryllium
disease (CBD). This disease causes fatigue, weakness, night sweats and can cause
difficulty in breathing and a persistent dry cough. It can result in anorexia, weight
loss, and may also lead to right-side heart enlargement and heart disease in advanced
cases.
Cadmium
Cadmium is a chemical element with the symbol Cd and atomic number 48.
About three-quarters of cadmium is used in batteries, predominantly in rechargeable
nickel-cadmium batteries. Most of the remaining quarter is used mainly for pigments,
coatings and plating, and as stabilizers for plastics.
Cadmium poisoning is an occupational hazard associated with industrial processes
such as metal plating and the production of nickel-cadmium batteries, pigments,
plastics, and other synthetics. The primary route of exposure in industrial settings is
inhalation. Inhalation of cadmium-containing fumes can result initially in metal fume
fever but may progress to chemical pneumonitis, pulmonary edema, and death.
Cadmium and several cadmium-containing compounds are known carcinogens and
can induce many types of cancer.
Carbon tetrachloride
Carbon tetrachloride, is the organic compound with the formula CCl4. It is a reagent
in synthetic chemistry and was formerly widely used in fire extinguishers and as a
precursor to refrigerants.
Chronic exposure to carbon tetrachloride can cause liver and kidney damage and
could result in cancer.
Chloroform
Chloroform, also known as trichloromethane (TCM) and methyl trichloride, is a
chemical compound with formula CHCl3.
The major use of chloroform today is in the production of the refrigerant R-22,
commonly used in the air conditioning business. However, as the Montreal Protocol
takes effect, this use can be expected to decline as R-22 is replaced by refrigerants
that are less liable to result in ozone depletion. Small amounts of chloroform are used
as a solvent in the pharmaceutical industry and for producing dyes and pesticides.
Chronic chloroform exposure may cause damage to the liver (where chloroform is
metabolized to phosgene COCl2) and to the kidneys, and some people develop sores
when the skin is immersed in chloroform.
Cobalt
Cobalt is a hard, lustrous, grey metal, a chemical element with symbol Co and atomic
number 27.
Cobalt is used in the preparation of magnetic, wear-resistant, and high-strength alloys.
Cobalt blue (cobalt(II) aluminate, CoAl2O4) gives a distinctive deep blue color to
glass, ceramics, inks, paints, and varnishes.
Cobalt-60 (Co-60 or 60Co) is useful as a gamma ray source (sterilization of medical
supplies, and medical waste; radiation treatment of foods for sterilization) and in
radiotherapy.
Although cobalt is an essential element for life in minute amounts, at higher levels of
exposure it shows mutagenic and carcinogenic.
Acute high-dose exposures to the gamma emissions can cause severe burns and death.
Extended exposures increase the risk of morbidity or mortality from cancer.
Cyanide
A cyanide is any chemical compound that contains the cyano group (C≡N), which
consists of a carbon atom triple-bonded to a nitrogen atom.
Gold and silver cyanides are among the very few soluble forms of these metals, and
cyanides are thus used in mining as well as electroplating, metallurgy, jewelry, and
photography. Cyanides are used as insecticides for the fumigating of ships. Cyanide
salts are used for killing ants, and have in some places been used as rat poison (the
less toxic poison arsenic is more common.
Cyanide is an inhibitor of the enzyme cytochrome c oxidase (also known as aa3) in the
fourth complex of the electron transport chain (found in the membrane of the
mitochondria of eukaryotic cells.) It attaches to the iron within this protein. The
binding of cyanide to this cytochrome prevents transport of electrons from
cytochrome c oxidase to oxygen. As a result, the electron transport chain is disrupted,
meaning that the cell can no longer aerobically produce ATP for energy. Tissues that
mainly depend on aerobic respiration, such as the central nervous system and the
heart, are particularly affected.
Bis(2-ethylhexyl) phthalate
Bis(2-ethylhexyl)phthalate, commonly abbreviated DEHP, is an organic compound
with the formula C6H4(CO2C8H17)2.
DEHP is widely used as a plasticizer in manufacturing of articles made of PVC.
Plastics may contain 1% to 40% of DEHP. It is also used as a hydraulic fluid and as a
dielectric fluid in capacitors. DEHP also finds use as a solvent in lightsticks.
Concerns instead focus on its potential as an endocrine disruptor (Endocrine
disruptors are exogenous substances that act like hormones in the endocrine system
and disrupt the physiologic function of endogenous hormones).
Polychlorinated dibenzodioxins
General structure of PCDDs where n and m can range from 0 to 4
Polychlorinated dibenzodioxins (PCDDs), or simply dioxins, are a group of
halogenated organic compounds. They are commonly referred to as dioxins.
Dioxins occur as by-products in the manufacture of organochlorides, in the
incineration of chlorine-containing substances such as PVC (polyvinyl chloride), in
the bleaching of paper.
Members of the PCDD family have been shown to bioaccumulate in humans and
wildlife due to their lipophilic properties, and are known teratogens, mutagens, and
suspected human carcinogens. Other effects in humans may include:
Central and peripheral nervous system pathology
Thyroid disorders
Damage to the immune systems.
Endometriosis
Diabetes
Formaldehyde
Formaldehyde is a chemical compound with the formula H2CO.
Formaldehyde is a common building block for the synthesis of more complex
compounds and materials. In approximate order of decreasing consumption, products
generated from formaldehyde include urea formaldehyde resin, melamine resin,
phenol formaldehyde resin, polyoxymethylene plastics, 1,4-butanediol, and methylene
diphenyl diisocyanate. It is used as the wet-strength resin added to sanitary paper
products such as (listed in increasing concentrations injected into the paper machine
headstock chest) facial tissue, table napkins, and roll towels. It is also used as an
ingredient by some shampoo manufacturers.
Formaldehyde can be toxic, allergenic, and carcinogenic.
Hexane
Hexane is an alkane hydrocarbon with the chemical formula CH3(CH2)4CH3 or C6H14.
Hexane isomers are largely unreactive, and are frequently used as an inert solvent in
organic reactions because they are very non-polar. They are also common constituents
of gasoline and glues used for shoes, leather products, and roofing. Additionally, it is
used in solvents to extract oils for cooking and as a cleansing agent for shoe, furniture
and textile manufacturing. In laboratories, hexane is used to extract oil and grease
from water and soil.
Chronic intoxication from hexane has been observed in recreational solvent abusers
and in workers in the shoe manufacturing, furniture restoration and automobile
construction industries. The initial symptoms are tingling and cramps in the arms and
legs, followed by general muscular weakness. In severe cases, atrophy of the skeletal
muscles is observed, along with a loss of coordination and problems of vision.
Hydrazine
Hydrazine is a chemical compound with the formula N2H4. It is a colourless liquid
with an ammonia-like odor and is derived from the same industrial chemistry
processes that manufacture ammonia. Hydrazine is highly toxic and dangerously
unstable, and is usually handled as 60% (saturated) aqueous solution for safety
reasons.
Hydrazine is mainly used as a blowing agent in preparing polymer foams, but
significant applications also include its uses as a precursor to polymerization catalysts
and pharmaceuticals. Additionally, hydrazine is used as rocket fuel and to prepare the
gas precursors used in air bags.
Effects to the lungs, liver, spleen, and thyroid have been reported in chronic exposures
to hydrazine via inhalation. Increased incidences of lung, nasal cavity, and liver
tumors have been observed.
Hydrogen fluoride
Hydrogen fluoride is a chemical compound with the formula HF. It is the principal
industrial source of fluorine, often in the aqueous form as hydrofluoric acid, and thus
is the precursor to many important compounds including pharmaceuticals and
polymers (e.g. Teflon). HF is widely used in the petrochemical industry and a
component of many superacids.
Upon contact with moisture, including tissue, hydrogen fluoride immediately converts
to hydrofluoric acid (HF).
HF is known to etch bone, and since it penetrates the skin it can weaken bones
without destroying the skin.[6] More seriously, it can absorb into blood through skin
and react with blood calcium, causing cardiac arrest.
Hydrogen peroxide
Hydrogen peroxide (H2O2) is a very pale blue liquid which appears colourless in a
dilute solution, slightly more viscous than water. It is a weak acid. It has strong
oxidizing properties and is therefore a powerful bleaching agent that is mostly used
for bleaching paper, but has also found use as a disinfectant, as an oxidizer, as an
antiseptic, and in rocketry.
Concentrated hydrogen peroxide (>50%) is corrosive, and even domestic-strength
solutions can cause irritation to the eyes, mucous membranes and skin. Swallowing
hydrogen peroxide solutions is particularly dangerous, as decomposition in the
stomach releases large quantities of gas (10 times the volume of a 3% solution)
leading to internal bleeding. Inhaling over 10% can cause severe pulmonary irritation.
Hydrogen sulfide
Hydrogen sulfide (or hydrogen sulphide) is the chemical compound with the formula
H2S.
Several organosulfur compounds are produced using hydrogen sulfide. It is widely
used in analytical chemistry.
Hydrogen sulfide is also used in the separation of deuterium oxide, i.e. heavy water,
from normal water.
Under the term 'liver of sulfur,' it is used in silver jewelry making to change the
finished color of silver items to a darker patina which can range from a pale gold
color through to a dark, oily bluish-green color.
Hydrogen sulfide is considered a broad-spectrum poison, meaning that it can poison
several different systems in the body, although the nervous system is most affected.
The toxicity of H2S is comparable with that of hydrogen cyanide. It forms a complex
bond with iron in the mitochondrial cytochrome enzymes, thereby blocking oxygen
from binding and stopping cellular respiration
Lead
Lead is a main group element with a symbol Pb. Lead has the atomic number 82.
Lead is used in building construction, lead-acid batteries, bullets and shot, weights,
and is part of solder, fusible alloys and radiation shields.
It is rapidly absorbed into the bloodstream and is believed to have adverse effects on
the central nervous system, the cardiovascular system, kidneys, and the immune
system.
In the human body, lead inhibits porphobilinogen synthase and ferrochelatase,
preventing both porphobilinogen formation and the incorporation of iron into
protoporphyrin IX, the final step in heme synthesis. This causes ineffective heme
synthesis and subsequent microcytic anemia.
A house painter affected by
chronic lead poisoning. Wasted
muscles and wrist drop are telltale symptoms of lead
poisoning.
Tetra-ethyl lead
Tetra-ethyl lead, abbreviated TEL, is an organometallic compound with the formula
(CH3CH2)4Pb. Once a common antiknock additive in gasoline (petrol), TEL usage
was largely discontinued because of the toxicity of lead and its deleterious effect on
catalytic converters. It is still used as an additive in aviation fuel for piston engine
powered aircraft.
Manganese
Manganese is a chemical element, designated by the symbol Mn. It has the atomic
number 25.
As a free element, manganese is a metal with important industrial metal alloy uses.
Manganese ions are variously colored, and are used industrially as pigments and as
oxidation chemicals.
Manganese poisoning has been linked to impaired motor skills and cognitive
disorders. A form of neurodegeneration similar to Parkinson's Disease called
"manganism" has been linked to manganese exposure
Mercury
Mercury is a chemical element with the symbol Hg and atomic number 80.
Mercury is used primarily for the manufacture of industrial chemicals or for electrical
and electronic applications. It is used in some thermometers, especially ones which
are used to measure high temperatures. Other uses:
Gaseous mercury is used in mercury-vapour lamps and some "neon sign" type
advertising signs and fluorescent lamps.
Hat making: Animal skins were rinsed in an orange solution (the term "carroting"
arose from this color) of the mercury compound mercuric nitrate,
Cosmetics: Mercury is widely used in the manufacture of mascara. In 2008,
Minnesota became the first state in the US to ban intentionally added mercury in
cosmetics, giving it a tougher standard than the federal government.
Production of chlorine and caustic soda: Chlorine is produced from sodium chloride
(common salt, NaCl) using electrolysis to separate the metallic sodium from the
chlorine gas. Usually the salt is dissolved in water to produce a brine. By-products of
any such chloralkali process are caustic soda (sodium hydroxide (NaOH)) and
hydrogen (H2). By far the largest use of mercury in the late 1900s was in the mercury
cell process (also called the Castner-Kellner process) where metallic sodium is
formed as an amalgam at a cathode made from mercury; this sodium is then reacted
with water to produce sodium hydroxide. Many of the industrial mercury releases of
the 1900s came from this process, although modern plants claimed to be safe in this
regard. After about 1985, all new chloralkali production facilities that were built in
the United States used either membrane cell or diaphragm cell technologies to
produce chlorine.
Dentistry: The element mercury is the main ingredient in dental amalgams.
Mining: Mercury was also used in gold and silver mining.
Methylmercury
Methylmercury (sometimes methyl mercury) is an organometallic cation with the
formula [CH3Hg]+. It is a bioaccumulative environmental toxicant.
"Methylmercury" is a shorthand for "monomethylmercury", and is more correctly
"monomethylmercuric cation". It is composed of a methyl group (CH3-) bonded to a
mercury atom; its chemical formula is CH3Hg+ (sometimes written as MeHg+). As a
positively charged ion it readily combines with anions such as chloride (Cl-),
hydroxide (OH-) and nitrate (NO3-).
Dimethylmercury
Dimethylmercury ((CH3)2Hg) is a flammable, colorless liquid, and one of the
strongest known neurotoxins.
Ethylmercury
Ethylmercury (sometimes ethyl mercury) is a cation composed of an ethyl group and
a mercury atom; its chemical formula is C2H5Hg+.
Mercury poisoning is caused by sufficient exposure to elemental mercury or mercury
compounds. The consumption of fish is by far the most significant source of
ingestion-related mercury exposure in humans, although plants and livestock also
contain mercury due to bioaccumulation of mercury from soil, water and atmosphere,
and due to biomagnification by ingesting other mercury-containing organisms.
Exposure to mercury can occur from breathing contaminated air, or from improper
use or disposal of mercury and mercury-containing objects, for example, after spills of
elemental mercury or improper disposal of fluorescent light bulbs.
Important human-generated sources include gold production, non-ferrous metal
production, cement production, waste disposal, crematoria, caustic soda production,
pig iron and steel production, mercury production (mostly for batteries), and biomass
burning.
Mercury and many of its chemical compounds, especially organomercury compounds,
can also be readily absorbed through direct contact with bare, or in some cases (such
as dimethylmercury) insufficiently protected, skin. Mercury and its compounds are
commonly used in chemical laboratories, hospitals, dental clinics, and facilities
involved in the production of items such as fluorescent light bulbs, batteries, and
explosives.
Mercury poisoning's effects partially depend on whether it has been caused by
exposure to elemental mercury, inorganic mercury compounds (as salts), or
organomercury compounds.
Mechanism
Mercury damages the central nervous system, endocrine system, kidneys, and other
organs, and adversely affects the mouth, gums, and teeth. Exposure over long periods
of time or heavy exposure to mercury vapor can result in brain damage and ultimately
death. Mercury and its compounds are particularly toxic to fetuses and infants.
Women who have been exposed to mercury in pregnancy have sometimes given birth
to children with serious birth defects ( Minamata disease).
Mercury exposure in young children can have severe neurological consequences,
preventing nerve sheaths from forming properly. Mercury inhibits the formation of
myelin, the building block protein that forms these sheaths.[9]
There is some evidence that mercury poisoning may predispose to Young's syndrome
(men with bronchiectasis and low sperm count).[10]
Mercury poisoning's effects partially depend on whether it has been caused by
exposure to elemental mercury, inorganic mercury compounds (as salts), or
organomercury compounds.
Elemental mercury
Quicksilver (liquid metallic mercury) is poorly absorbed by ingestion and skin
contact. It is hazardous due to its potential to release mercury vapour. Some mercury
vapour is absorbed dermally but uptake by this route is only approximately 1% of that
by inhalation.
In humans, approximately 80% of inhaled mercury vapour is absorbed via the
respiratory tract where it enters the circulatory system and is distributed throughout
the body. Chronic exposure by inhalation, even at low concentrations in the range
0.7–42 μg/m3, has been shown to cause effects such as tremors, impaired cognitive
skills, and sleep disturbance in workers.
Inorganic mercury compounds
Mercury occurs inorganically as salts such as mercury(II) chloride. Mercury salts
primarily affect the gastro-intestinal tract and the kidneys, and can cause severe
kidney damage; however, as they can not cross the blood-brain barrier easily, mercury
salts inflict little neurological damage without continuous or heavy exposure. As two
oxidation states of mercury form salts (Hg+ and Hg2+), mercury salts occur in both
mercury(I) (or mercurous) and mercury(II) (mercuric) forms. Mercury(II) salts are
usually more toxic than their mercury(I) counterparts because their solubility in water
is greater; thus, they are more readily absorbed from the gastrointestinal tract.
Organic mercury compounds
Compounds of mercury tend to be much more toxic than the element itself, and
organic compounds of mercury are often extremely toxic and have been implicated in
causing brain and liver damage. The most dangerous mercury compound,
dimethylmercury, is so toxic that even a few microliters spilled on the skin, or even a
latex glove, can cause death.
Methylmercury is the major source of organic mercury for all individuals. It works its
way up the food chain through bioaccumulation in the environment, reaching high
concentrations among populations of some species. Larger species of fish, such as
tuna or swordfish, are usually of greater concern than smaller species.
Ethylmercury is a breakdown product of the antibacteriological agent
ethylmercurithiosalicylate, which has been used as a topical antiseptic and a vaccine
preservative. Its characteristics have not been studied as extensively as
methylmercury. It is cleared from the blood much more rapidly, with a half-life of 7
to 10 days, and it is metabolized much more quickly than methylmercury. It probably
does not have methylmercury's ability to cross the blood-brain barrier via a
transporter, but instead relies on simple diffusion to enter the brain.
Other exposure sources of organic mercury include phenylmercuric acetate and
phenylmercuric nitrate. These were used in indoor latex paints for their anti-mildew
properties, but were removed in 1990 because of cases of toxicity.