Beryllium Monoxide Toxicology
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metallurgy of rare earths,
and as components of microwawe ovens,
under extreme conditions,
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fine amorphous, white and odourless powder according to the heat
treatment at the time of preparation.
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magnesium powder can cause an explosive reaction.
Extinguishing Fire :
surrounding materials.
beryllium fire is very toxic: wear an autonomous respiratory
protection gear and protective clothing covering all of the body.
must be carried out by qualified personnel.
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modifications of working methods are not sufficient to reduce the
exposure to this substance, the wearing of an individual
protection apparatusr can be necessary.
accordance with the regulation.
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beryllium oxide, wear a respiratory protection apparatus if the
concentration in the work environment is higher than the action
level and even when the exposure is lower than this one.
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skin protection gear depends on the nature of the work to carry
out. In the presence of powder or dust of beryllium oxide, wear
protective clothing covering all of the body.
ocular protection gear depends on the nature of the work to carry
out and, if it is necessary, of the type of respiratory protection
gear used.
conditions of use.
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reacts violently and can produce an explosion.
melting point (2 530 °C).
less harmful effects, or a wet process.
fine particles or a cloud of dust.
install aspiration at the source.
where there is a risk of exposure to beryllium and its compounds,
just as the number of workers having access to these areas.
against particles (HEPA) to clean the equipment and the floor of
the working area.
Do not eat and do not drink while using this product.
change clothing after work.
(Double locker). Protection gears and working clothes including
shoes, should not leave the workplace.
one for work clothes, the other for personal clothes.
hazards are high, away from incompatible products, in a cool and
well ventilated place. Moreover, if the product is in the form of
powder, store in a tight container, well identified.
taken to avoid a leak or a spill of this product.
is dust, establish a limited access zone and limit access until
cleaning is completed. Cleaning should be carried out only by
qualified personnel.
products without wearing protective clothing covering all of the
body and an autonomous respiratory protection gear.
efficiency filtering vacuum cleaner against particles (HEPA).
by using a suitable technique in order to prevent the
contamination of the area.
into the environment. Beryllium oxide wastes in the form of powder
or dust must be recovered in a sealed container identified and
handed over to a firm which recycles it. If necessary, consult
concerned regional authorities.
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excess of the occupational standard can occur :
metallurgy, if beryllium-containing materials are melted or casted
and at the time of handling of slags and scum.
sanding, polishing or crushing pieces containing beryllium oxide.
beryllium or at the time of any process implying heating, such as
welding or cutting with a blowtorch.
the time of maintenance, cleaning or repairing equipment
contaminated such as furnaces, tanks or boilers in sectors such as
petroleum, metallurgy or energy.
parts intended for recovery.
firing solid BeO parts at temperature greater than 900 oC in a
moist atmosphere such as in a hydrogen atmosphere sintering
furnace.
slowly. What was not eliminated quickly, by the mucociliary
activity or phagocytosis of the particles, is retained several
months in the lungs and is gradually released into the blood.
by dissolution in the pulmonary fluids and a variable proportion
passes into blood.
low temperature calcined beryllium
oxide would be faster than that
of high temperature calcined
beryllium oxide because of its
greater solubility.
practically not absorbed through intact skin because they bind to
components of the skin (proteins and nucleic acids) to form lowly
diffusible complexes. However, it is thought that skin contact can
especially play a part in sensitizing following exposure to fine
particles.
very slightly absorbed by the digestive tract. The absorbed amount
depends on the dose and the solubility of the compounds. This
amount is limited by the formation of insoluble colloidal
phosphates in the intestine.
transported in the body adsorbed on plasmatic proteins in the form
of colloidal phosphate. In the
short run, they tend to
accumulate in the liver especially in the cases of important
exposures. In the long
run, one finds them mainly in the
lymphatic ganglia and the bones. They were also identified in the
blood of the umbilical cord and maternal blood.
metabolized. In the lungs, soluble beryllium salts are partially
transformed into insoluble salts.
competitive way many enzymes activated by magnesium or manganese,
in particular alkaline phosphatase.
through the formation of a beryllium-protein complex, because of
the small molecular weight of beryllium.
excreted mainly in the urine. Compounds which are not absorbed
into the body are excreted mainly in the feces following ingestion
by the oral route or by the pulmonary mucociliary clearance, and
the excretion depends on the solubility of the ingested compounds.
identified in mother's milk and colostrum.
during several years and persist a very long time after the
cessation of exposure.
the presence or the severity of berylliosis and the urinary
beryllium level.
beings but, one can say that in general according to animal
studies, the insoluble or not very soluble compounds and the
soluble compounds, are cleared from the pulmonary tissue in a
biphasic way initially with a half-life of a few days during which
30 to 50 % of the beryllium is eliminated.
to the solubility of the compounds suggests that the half-life of
the soluble compounds is of about a few weeks or a month while it
varies from months to years for the compounds which are little or
not soluble.
can be several years.
beryllium in the air corresponds to approximately 7 µg/L. in
the urine and 4 µg/L. in the blood. For a non-professionally
exposed population the urinary beryllium concentration is less
than 0,9 µg/l.
total amount of beryllium absorbed daily by the general population
is 423 ng following the inhalation of ambient air and from the
ingestion of food and water. The most important contribution comes
from the ingestion of water (300 ng) and food (120 ng).
susceptibility can play an important role in the development of
berylliosis. People suffering from chronic berylliosis are
carrying more frequently than controls a genetic marker :
(HLA-DPB1 Glu69). This allele would be present in 85 to 95% of the
patients and in only 30 to 45 % of the controls.
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weeks.
µg/m³ beryllium are usually associated with this acute
form, but these exposures are rare nowadays.
massive exposure to low
temperature calcined beryllium oxide. This was not reported following exposure to
high temperature calcined
beryllium oxide.
in :
such as pulmonary oedema and fibrosis.
cases. Convalescence can vary from 4 to 6 months.
chronic form.
chips of beryllium oxide under the skin can cause the formation of
painless ulcers or subcutaneous granulomas after a few
months.
particles or by the mechanical action of dusts or of the
particles. Exposure can result from the direct contact with
airborne particles (particles, dusts, or powders), or following
ocular contact with the hands or soiled clothing.
workers exposed according to the kind of work carried out. The
appearance and the progression of the disease are partly due to
individual genetic
susceptibilities which act in
connection with the exposure.
beryllium concentrations or to its compounds can cause
berylliosis. The low temperature
(500°C) calcined beryllium oxide would be more sensitizing that the
high temperature (1 000°C)
calcined beryllium oxide because
of its greater solubility.
creates a ground favourable to the development of a cellular
mediated immunological response. Beryllium acts in combination
with peptides as a hapten which activates the effector cells to
produce cytokins. These last ones stimulate the inflammatory and
immunizing reaction of various pulmonary cells while acting on the
development of the granulomatous inflammation associated with
chronic berylliosis.
appear a few months only after the beginning of the exposure or
several years after the end of an exposure having lasted only a
few months. Usually the disease appears within a delay varying
from a few months to 5 years, seldom up to 20 or 30 years.
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tests,
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but without symptom,
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symptoms.
in the morning or upon exertion, accompanied by chest pain and a
feeling of tiredness.
loss of weight,
spleen,
the formation of non-caseous granulomas accompanied by alveolitis.
When the effect progresses, diffuse interstitial fibrosis
settles.
spontaneous pneumothorax and cardiopulmonary diseases.
factors such as a re-exposure, infection, surgical operation,
pregnancy, etc.
in a gradual way, but can also be very variable.
minority of people remains asymptomatic for long periods of time,
while the majority presents symptoms, while carrying out an almost
normal life.
cardiorespiratory insufficiency (cor pulmonale) causing death in
the most advanced cases.
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pulmonary function, airway diseases, or conditions such as asthma,
emphysema, chronic bronchitis, etc can incur more deterioration if
dust or vapors are inhaled.
neurological, circulatory, hematologic, or urinary systems have
already occurred, suitable sreening examinations should be carried
out in individuals who can be exposed to hazards when handling and
using this material
Exposure :
(BeLPT) :
sensitive than clinical evaluation and has a great predictive
value in spite of its limitations.
from bronchoalveolar lavage, the predictive value is nearly 100 %
of the cases, but this test is less frequent because the sampling
requires a more invasive procedure.
possibility of sensitization or berylliosis, particularly in
smokers.
distinction between berylliosis and other pulmonary diseases,
particularly sarcoidosis.
berylliosis monitoring has identified a population of workers
sensitized without apparent symptom of the disease. These
sensitized workers had pulmonary function tests, a tolerance to
exercise, pulmonary X-rays and biopsies that were normal.
must remain under medical supervision and be re-examined at
regular intervals to detect the first signs of the disease.
It is estimated that annually,
approximately 10 % of the sensitized individuals, will develop the
disease.
monitoring should be conducted periodically among workers exposed
to beryllium, every 2 to 5 years, according to the level of
exposure.
sensitized workers every 1 to 2 years and immediately in workers
with subclinical impairment, or sensitized with symptoms or
unexplained pulmonary disease.
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certain number of cases that the (BeLPT) missed, the blood test
detecting about from 80% to 90% of the cases.
berylliosis. However, certain drugs are effective to reduce the
effects and to slow down the progression of the disease. The use
of these drugs, usually corticosteroids, must be permanent.
workers, the use of drugs is not necessary, but they must be the
subjects of a medical follow-up in order to evaluate the
progression of the disease.
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Several cases of dermatitis of the allergic type (eczema) were
reported in workers exposed to beryllium and its compounds. These
cases were confirmed by skin patch tests with several beryllium
salts (sulphate, fluoride, chloride and others).
barrier.
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possible to make an adequate evaluation of the effects on
reproduction.
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animals..
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A.C.G.I.H., N.T.P.
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possible to make an adequate evaluation of mutagenic effects. The
tests of DNA effects and of cellular transformation proved to be
positive for low temperature calcined beryllium oxide whereas
doubtful results were obtained in the same tests for high
temperature calcined beryllium oxide.
dust, bring the person into a ventilated place and place him in a
half-sitting position. If he does not breathe, give him artificial
respiration. In the event of respiratory difficulties, give him
oxygen.
medical emergency department.
minutes or until the product is removed.
Wash the skin with water and soap. Completely clean cuts or
wounds. Any beryllium oxide particle lodged accidentally under the
skin must be removed.
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Pondérée (VEMP) :
(Beryllium).
reduced to the minimum.
prohibited
last edition.
Toxic Exposures, Sullivan & Krieger; last edition.
Industrial Materials, Lewis C., last edition.
Intoxications Professionnelles, Lauwerys R. last
edition.
Proctor & Hughes, 4th edition.
Toxicologique.