YENEPOYA DENTAL COLLEGE
DA/DH ASSIGNMENT
NAME:
HANEENA
SUBJECT :
DENTAL
HISTOLOGY
SUBMITTED TO:
DR.MAJI
JOSE
SUBMITTED
ON:
16-09-2012
TOPIC
:
HEALTH HAZARDS OF
FORMALIN
HEALTH HAZARDS ASSOCIATED
WITH BREATHING IN
FORMALDEHYDE SOLUTIONS
Formaldehyde solutions can release formaldehyde gas,
which is extremely irritating and very toxic if inhaled,
posing a very serious inhalation hazard. The amount of
gas released depends on the concentration of
formaldehyde and other ingredients present in the
formulation
No case reports of death from inhalation exposure to
formaldehyde were located, but deaths have been observed in
animal studies following exposure to concentrations that would
produce intolerable irritation.. The odour of formaldehyde gas can
be recognized at concentrations as low as 0.03-1.9 ppm. It causes
mild to moderate irritation of the nose and throat at 0.3-3 ppm.
Up to 20% of the population are more responsive and may react
acutely to formaldehyde at very low concentrations (0.25 ppm).
Exposure to 10 ppm causes severe irritation of the upper
respiratory tract, with a burning sensation of the nose and throat.
Other effects include coughing, choking and vomiting. Exposure to
50 ppm or higher may lead to inflammation of the lung
(pneumonitis) or to a potentially fatal accumulation of fluid in the
lungs (pulmonary edema).
Symptoms of pulmonary edema (chest pain and shortness of breath)
can be delayed for up to 24 or 48 hours after exposure.
In a study of funeral home employees, exposure to 0.25-1.77 ppm
formaldehyde produced nose irritation, sneezing, coughing, and
headaches in an unspecified number of embalmers. Thirty-three
volunteers exposed to 0, 0.25, 0.5, 1 or 2 ppm formaldehyde
(generated from heating paraformaldehyde) for 90 minutes experienced
irritation of the nose and throat at all concentrations, with severity
increasing with concentration. In a study of 23 students exposed to
0.02-2.7 ppm (cited as 0.02-3.3 mg/m3) and phenol from cadavers,
most experienced nose and throat irritation, headache, dizziness, and
cough. Of 12 who had post-exposure testing, one showed a significant
decrease in pulmonary function. The effects were attributed to the
formaldehyde exposure
when formaldehyde solutions comes
into contact with my skin
Formaldehyde solutions are considered corrosive to the skin.
However, they have only caused mild to moderate skin irritation in
animal studies. There is little human information on the irritancy of
formaldehyde solutions, although their potential for irritation is
widely accepted.
Formaldehyde solutions form corrosive formic acid upon standing.
Corrosive materials can cause severe burns, blistering and
permanent scarring of the skin. Any skin contact may also involve
inhalation exposure.
Action of formaldehyde solutions on
eyes
Formaldehyde solutions are corrosive to the eyes.
Corrosive materials can cause severe eye damage with
permanently altered vision or blindness. There are several
case reports of eye injury occurring when formaldehyde
solutions were accidentally splashed into the eyes.
Characteristically, formaldehyde eye injuries are
immediately painful but can leave the eye looking normal
for at least an hour or two after exposure. Over the course
of the next 12 hours, very severe eye damage becomes
apparent
Formaldehyde gas is also irritating to the eyes. The threshold for mild
eye irritation may be as low as 0.01 ppm. Although, continued
exposure may result in some acclimatization. Twelve volunteers exposed
for 5 minutes to formaldehyde (composition not specified), mixed with
other non-irritating pollutants, could detect and react to 0.01 ppm,
with 0.2 ppm causing light to medium eye irritation, and 0.6 ppm
causing medium to severe irritation. Exposure to 1 ppm formaldehyde
gas (generated by heating paraformaldehyde) for 6 minutes caused
slight to moderate eye irritation in 27 volunteers. Thirty-three
volunteers exposed to 0, 0.25, 0.5, 1 or 2 ppm formaldehyde gas
(generated from heating paraformaldehyde) for 90 minutes experienced
irritation of the eyes at all concentrations, with severity increasing with
concentration
When formaldehyde solution is accidentally
swallowed : (enters the digestive system)
Formaldehyde solutions are toxic if ingested, based on animal and human
information. Ingestion of formalin (37-50% water solutions of formaldehyde; 015% methanol) in accidental, suicidal or homicidal cases has caused corrosive
burning of the mouth, throat and digestive tract with vomiting of tissue and blood.
Ingested formaldehyde is rapidly converted to formic acid, which can cause
metabolic acidosis, and damage to the liver and kidneys leading to jaundice and
swelling of body tissues. In severe cases, there may be convulsions, central nervous
system depression and death. The fatal dose for formaldehyde in humans is
estimated to be about 60-90 mL of formalin (317-475 mg/kg of formaldehyde
assuming a 37% solution of formalin and a 70 kg person). The presence of
methanol may contribute to the overall toxicity of ingested formalin. Ingestion is not
a typical route of occupational exposure.
formaldehyde solutions cause
cancer
Formaldehyde is carcinogenic to humans. The International Agency
for Research on Cancer has concluded there is sufficient evidence
that formaldehyde causes nasopharyngeal cancer in humans. There
is limited evidence for cancer of the nasal cavity and paranasal
sinuses and "strong but not sufficient evidence" for leukemia. There
are many human population studies on the increase of respiratory
cancers in people occupationally exposed to formaldehyde. These
studies have been extensively reviewed elsewhere and are not reviewed
here
Formaldehyde does not accumulate. It is a
normal intermediate metabolite and is found in
all cells. It is very reactive and readily bonds to
proteins and nucleic acids. It has a half-life in
the blood of about 90 seconds and is rapidly
metabolized to formic acid (which is excreted in
the urine), converted to carbon dioxide (which is
exhaled), or used to synthesize proteins and
nucleic acids
THANK YOU
BY : HANEENA