Medical Management Guidelines for Formaldehyde
(HCHO)
CAS# 50-00-0
UN# 1198, 2209 (formalin)
PDF Versionpdf icon[235 KB]
Synonyms include formalin, formic aldehyde,
methanal, methyl aldehyde, methylene oxide, oxomethane, and
paraform.
- Persons exposed only to formaldehyde vapor do not pose
substantial risks of secondary contamination. Persons whose
clothing or skin is contaminated with a solution of formaldehyde
can cause secondary contamination by direct contact or through
off-gassing vapor.
- Formaldehyde is a colorless, highly toxic, and flammable
gas at room temperature that is slightly heavier than air.
It has a pungent, highly irritating odor that is detectable
at low concentrations, but may not provide adequate warning
of hazardous concentrations for sensitized persons.
- It is used most often in an aqueous solution stabilized
with methanol (formalin).
- Most formaldehyde exposures occur by inhalation or by
skin or eye contact. Formaldehyde is absorbed well by the
lungs, gastrointestinal tract, and, to a lesser extent,
skin.
General Information
Description
Formaldehyde is a nearly colorless gas
with a pungent, irritating odor even at very low concentrations
(below 1 ppm). Its vapors are flammable and explosive. Because
the pure gas tends to polymerize, it is commonly used and
stored in solution. Formalin, the aqueous solution of formaldehyde
(30% to 50% formaldehyde), typically contains up to 15% methanol
as a stabilizer.
Routes of Exposure
Inhalation
Most formaldehyde exposures occur by
inhalation or by skin/eye contact. Formaldehyde vapor is readily
absorbed from the lungs. In cases of acute exposure, formaldehyde
will most likely be detected by smell; however, persons who
are sensitized to formaldehyde may experience headaches and
minor eye and airway irritation at levels below the odor threshold
(odor threshold is 0.5 to 1.0 ppm; OSHA PEL is 0.75 ppm).
For sensitized persons, odor is not an adequate indicator
of formaldehyde's presence and may not provide reliable warning
of hazardous concentrations. Odor adaptation can occur.
Low-dose acute exposure can result in headache, rhinitis,
and dyspnea; higher doses may cause severe mucous membrane
irritation, burning, and lacrimation, and lower respiratory
effects such as bronchitis, pulmonary edema, or pneumonia.
Sensitive individuals may experience asthma and dermatitis,
even at very low doses. Formaldehyde vapors are slightly heavier
than air and can result in asphyxiation in poorly ventilated,
enclosed, or low-lying areas.
Children exposed to the same levels
of formaldehyde as adults may receive larger doses because
they have greater lung surface area:body weight ratios and
increased minute volumes:weight ratios. In addition, they
may be exposed to higher levels than adults in the same location
because of their short stature and the higher levels of formaldehyde
found nearer to the ground.
Skin/Eye Contact
Ocular exposure to formaldehyde vapors
produces irritation and lacrimation. Depending on the concentration,
formaldehyde solutions may cause transient discomfort and
irritation or more severe effects, including corneal opacification
and loss of vision. Formaldehyde is absorbed through intact
skin and may cause irritation or allergic dermatitis; rapid
metabolism makes systemic effects unlikely following dermal
exposure.
Children are more vulnerable to toxicants
absorbed through the skin because of their relatively larger
surface area:body weight ratio.
Ingestion
Ingestion of as little as 30 mL (1 oz.)
of a solution containing 37% formaldehyde has been reported
to cause death in an adult. Ingestion may cause corrosive
injury to the gastrointestinal mucosa, with nausea, vomiting,
pain, bleeding, and perforation. Corrosive injuries are usually
most pronounced in the pharyngeal mucosa, epiglottis and esophagus.
Systemic effects include metabolic acidosis, CNS depression
and coma, respiratory distress, and renal failure.
Sources/Uses
Formaldehyde is synthesized by the oxidation
of methanol. It is among the 25 most abundantly produced chemicals
in the world and is used in the manufacture of plastics, resins,
and urea-formaldehyde foam insulation. Formaldehyde or formaldehyde-containing
resins are used in the manufacture of chelating agents, a
wide variety of organic products, glass mirrors, explosives,
artificial silk, and dyes. It has been used as a disinfectant,
germicide, and in embalming fluid. In the agricultural industry,
formaldehyde has been used as a fumigant, preventative for
mildew in wheat and rot in oats, a germicide and fungicide
for plants, an insecticide, and in the manufacture of slow-release
fertilizers. Formaldehyde is found in construction materials
such as plywood adhesives. Formaldehyde also is or has been
used in the sugar, rubber, food, petroleum, pharmaceuticals,
and textiles industries.
Standards and Guidelines
OSHA PEL (permissible exposure limit)
= 0.75 ppm (averaged over an 8-hour workshift)
OSHA STEL (short-term exposure limit)
= 2 ppm (15 minute exposure)
NIOSH IDLH (immediately dangerous to
life or health) = 20 ppm
AIHA ERPG-2 (emergency response planning
guideline) (the maximum airborne concentration below which
it is believed that nearly all individuals could be exposed
for up to 1 hour without experiencing or developing irreversible
or other serious health effects or symptoms which could impair
an individual's ability to take protective action) = 10 ppm
Physical Properties
Description: Nearly colorless
gas with a pungent, irritating odor
Warning properties: Odor is detectable
at less than 1 ppm, but many sensitive persons experience
symptoms below the odor threshold.
Molecular weight: 30.0 daltons
Boiling point (760 mm Hg): - 6°F
(-21°C)
Vapor pressure: 3883 mm Hg at
77°F (25°C)
Gas density: 1.07 (air = 1)
Water solubility: 55% at 68°F
(20°C)
Flammability: Flammable gas between
7% and 73% at 77°F (25°C) (concentration in air);
combustible liquid (formalin)
Incompatibilities
Formaldehyde reacts with strong oxidizers,
alkalis, acids, phenols, and urea. Pure formaldehyde has a
tendency to polymerize.
Health Effects
- Formaldehyde is an eye, skin, and respiratory tract irritant.
Inhalation of vapors can produce narrowing of the bronchi
and an accumulation of fluid in the lungs.
- Children may be more susceptible than adults to the respiratory
effects of formaldehyde.
- Formaldehyde solution (formalin) causes corrosive injury
to the gastrointestinal tract, especially the pharynx, epiglottis,
esophagus, and stomach.
- The systemic effects of formaldehyde are due primarily
to its metabolic conversion to formate, and may include
metabolic acidosis, circulatory shock, respiratory insufficiency,
and acute renal failure.
- Formaldehyde is a potent sensitizer and a probable human
carcinogen.
Acute Exposure
Formaldehyde vapor produces immediate
local irritation in mucous membranes, including eyes, nose,
and upper respiratory tract. Ingestion of formalin causes
severe injury to the gastrointestinal tract. The exact mechanism
of action of formaldehyde toxicity is not clear, but it is
known that it can interact with molecules on cell membranes
and in body tissues and fluids (e.g., proteins and DNA) and
disrupt cellular functions. High concentrations cause precipitation
of proteins, which results in cell death. Absorption from
the respiratory tract is very rapid; absorption from the gastrointestinal
tract is also rapid, but may be delayed by ingestion with
food. Once absorbed, formaldehyde is metabolized to formic
acid, which may cause acid-base imbalance and a number of
other systemic effects.
Children do not always respond to chemicals
in the same way that adults do. Different protocols for managing
their care may be needed.
CNS
Malaise, headache, sleeping disturbances,
irritability, and impairment of dexterity, memory, and equilibrium
may result from a single, high level, exposure to formaldehyde.
Respiratory
Even fairly low concentrations of formaldehyde
can produce rapid onset of nose and throat irritation, causing
cough, chest pain, shortness of breath, and wheezing. Higher
exposures can cause significant inflammation of the lower
respiratory tract, resulting in swelling of the throat, inflammation
of the windpipe and bronchi, narrowing of the bronchi, inflammation
of the lungs, and accumulation of fluid in the lungs. Pulmonary
injury may continue to worsen for 12 hours or more after exposure.
Previously sensitized individuals can
develop severe narrowing of the bronchi at very low concentrations
(e.g., 0.3 ppm). Bronchial narrowing may begin immediately
or can be delayed for 3 to 4 hours; effects may worsen for
up to 20 hours after exposure and can persist for several
days.
Exposure to certain chemical irritants
can lead to Reactive Airway Dysfunction Syndrome (RADS), a
chemically- or irritant-induced type of asthma.
Children may be more vulnerable to corrosive
agents than adults because of the relatively smaller diameter
of their airways.
Children may be more vulnerable because
of relatively increased minute ventilation per kg and failure
to evacuate an area promptly when exposed.
Metabolic
Accumulation of formic acid can cause
an anion-gap acid-base imbalance. If formalin is ingested,
absorption of the methanol stabilizer may contribute to the
imbalance and can result in an osmolal gap, as well as an
anion gap.
Immunologic
In persons who have been previously sensitized,
inhalation and skin contact may cause various skin disorders,
asthma-like symptoms, anaphylactic reactions and, rarely,
hemolysis. The immune system in children continues to develop
after birth, and thus, children may be more susceptible to
certain chemicals.
Gastrointestinal
Ingestion of aqueous solutions of formaldehyde
can result in severe corrosive injury to the esophagus and
stomach. Nausea, vomiting, diarrhea, abdominal pain, inflammation
of the stomach, and ulceration and perforation of the oropharynx,
epiglottis, esophagus, and stomach may occur. Both formaldehyde
and the methanol stabilizer are easily absorbed and can contribute
to systemic toxicity.
Ocular
Exposure to low concentrations of formaldehyde
vapor can cause eye irritation, which abates within minutes
after exposure has ended. Formalin splashed in the eyes can
result in corneal ulceration or cloudiness of the eye surface,
death of eye surface cells, perforation, and permanent loss
of vision; these effects may be delayed for 12 hours or more.
Dermal
Exposure to formaldehyde vapor or to
formalin solutions can cause skin irritation and burns. In
sensitized persons, contact dermatitis may develop at very
low exposure levels.
Potential Sequelae
In survivors of inhalation injury, pulmonary
function usually returns to normal. Eye exposure to high concentrations
of formaldehyde vapor or formalin can eventually cause blindness.
Narrowing of the esophagus and severe corrosive damage to
the stomach lining can result from ingesting formalin.
Chronic Exposure
The major concerns of repeated formaldehyde
exposure are sensitization and cancer. In sensitized persons,
formaldehyde can cause asthma and contact dermatitis. In persons
who are not sensitized, prolonged inhalation of formaldehyde
at low levels is unlikely to result in chronic pulmonary injury.
Adverse effects on the central nervous system such as increased
prevalence of headache, depression, mood changes, insomnia,
irritability, attention deficit, and impairment of dexterity,
memory, and equilibrium have been reported to result from
long-term exposure. Chronic exposure may be more serious for
children because of their potential longer latency period.
Carcinogenicity
The Department of Health and Human Services
has determined that formaldehyde may reasonably be anticipated
to be a carcinogen. In humans, formaldehyde exposure has been
weakly associated with increased risk of nasal cancer and
nasal tumors were observed in rats chronically inhaling formaldehyde.
Reproductive and Developmental Effects
There is limited evidence that formaldehyde
causes adverse reproductive effects. The TERIS database states
that the risk of developmental defects to the exposed fetus
ranges from none to minimal. Formaldehyde is not included
in Reproductive and Developmental Toxicants, a 1991
report published by the U.S. General Accounting Office (GAO)
that lists 30 chemicals widely acknowledged to have reproductive
and developmental consequences.
There have been reports of menstrual
disorders in women occupationally exposed to formaldehyde,
but they are controversial. Studies in experimental animals
have reported some effects on spermatogenesis. Formaldehyde
has not been proven to be teratogenic in animals and is probably
not a human teratogen at occupationally permissible levels.
Formaldehyde has been shown to have genotoxic properties in
human and laboratory animal studies producing sister chromatid
exchange and chromosomal aberrations.
Special consideration regarding the
exposure of pregnant women is warranted, since formaldehyde
has been shown to be a genotoxin; thus, medical counseling
is recommended for the acutely exposed pregnant woman.
Prehospital Management
- Victims exposed only to formaldehyde gas do not pose significant
risks of secondary contamination to personnel outside the
Hot Zone. Victims whose clothing or skin is contaminated
with a formaldehyde-containing solution (formalin) can secondarily
contaminate personnel by direct contact or through off-gassing
vapor.
- Inhalation of formaldehyde can cause airway irritation,
bronchospasm, and pulmonary edema.
- Absorption of large amounts of formaldehyde via any route
can cause severe systemic toxicity, leading to metabolic
acidosis, tissue and organ damage, and coma.
- There is no antidote for formaldehyde. Treatment consists
of supportive measures including decontamination (flushing
of skin and eyes with water, gastric lavage, and administration
of activated charcoal), administration of supplemental oxygen,
intravenous sodium bicarbonate and/or isotonic fluid, and
hemodialysis.
Hot Zone
Rescuers should be trained and appropriately
attired before entering the Hot Zone. If the proper equipment
is not available, or if rescuers have not been trained in
its use, assistance should be obtained from a local or regional
HAZMAT team or other properly equipped response organization.
Rescuer Protection
Formaldehyde is a highly toxic systemic
poison that is absorbed well by inhalation. The vapor is a
severe respiratory tract and skin irritant and may cause dizziness
or suffocation. Contact with formaldehyde solution may cause
severe burns to the eyes and skin.
Respiratory Protection: Positive-pressure,
self-contained breathing apparatus (SCBA) is recommended in
response situations that involve exposure to potentially unsafe
levels of formaldehyde vapor.
Skin Protection: Chemical-protective
clothing is recommended because formaldehyde can cause skin
irritation and burns.
ABC Reminders
Quickly access for a patent airway, ensure
adequate respiration and pulse. If trauma is suspected, maintain
cervical immobilization manually and apply a cervical collar
and a backboard when feasible.
Victim Removal
If victims can walk, lead them out of
the Hot Zone to the Decontamination Zone. Victims who are
unable to walk may be removed on backboards or gurneys; if
these are not available, carefully carry or drag victims to
safety.
Consider appropriate management of chemically
contaminated children, such as measures to reduce separation
anxiety if a child is separated from a parent or other adult.
Decontamination Zone
Victims exposed only to formaldehyde
vapor who have no skin or eye irritation may be transferred
immediately to the Support Zone. All others require decontamination
(see Basic Decontamination below).
Rescuer Protection
If exposure levels are determined to
be safe, decontamination may be conducted by personnel wearing
a lower level of protection than that worn in the Hot Zone
(described above).
ABC Reminders
Quickly access for a patent airway, ensure
adequate respiration and pulse. Stabilize the cervical spine
with a collar if trauma is suspected. Administer supplemental
oxygen as required. Assist ventilation with a bag-valve-mask
device if necessary.
Basic Decontamination
Victims who are able may assist with
their own decontamination. Remove and double-bag contaminated
clothing and personal belongings.
Flush liquid-exposed skin and hair with
plain water for 3 to 5 minutes. Wash area thoroughly with
soap and water when possible. Use caution to avoid hypothermia
when decontaminating children or the elderly. Use blankets
or warmers when appropriate.
Irrigate exposed or irritated eyes with
plain water or saline for 15 minutes. Remove contact lenses
if easily removable without additional trauma to the eye.
If pain or injury is evident, continue eye irrigation while
transferring the victim to the Support Zone.
In cases of formalin ingestion, do
not induce emesis. Victims who are conscious and able
to swallow should be given 4 to 8 ounces of water or milk.
Gastric lavage with a small bore NG tube should be considered
if it can be performed within 1 hour after ingestion. The
effectiveness of activated charcoal administration is unknown,
but it is suggested following lavage (administer activated
charcoal at 1 gm/kg, usual adult dose 60-90 g, child dose
25-50 g). A soda can and straw may be of assistance when offering
charcoal to a child.
Consider appropriate management of chemically
contaminated children at the exposure site. Also, provide
reassurance to the child during decontamination, especially
if separation from a parent occurs. If possible, seek assistance
from a child separation expert.
Transfer to Support Zone
As soon as basic decontamination is complete,
move the victim to the Support Zone.
Support Zone
Be certain that victims have been decontaminated
properly (see Decontamination Zone above). Persons
who have undergone decontamination or who have been exposed
only to vapor pose no serious risks of secondary contamination.
Support Zone personnel require no specialized protective gear
in such cases.
ABC Reminders
Quickly access for a patent airway. If
trauma is suspected, maintain cervical immobilization manually
and apply a cervical collar and a backboard when feasible.
Ensure adequate respiration and pulse. Administer supplemental
oxygen as required and establish intravenous access if necessary.
Place on a cardiac monitor. Watch for signs of airway swelling
and obstruction such as progressive hoarseness, stridor, or
cyanosis.
Additional Decontamination
Continue irrigating exposed skin and
eyes, as appropriate.
In cases of formalin ingestion, do
not induce emesis. If water has not been given previously,
administer 4 to 8 ounces of milk or water if the patient is
able to swallow.
Advanced Treatment
In cases of respiratory compromise secure
airway and respiration via endotracheal intubation. If not
possible, perform cricothyroidotomy if equipped and trained
to do so.
Treat patients who have bronchospasm
with aerosolized bronchodilators. The use of bronchial sensitizing
agents in situations of multiple chemical exposures may pose
additional risks. Consider the health of the myocardium before
choosing which type of bronchodilator should be administered.
Cardiac sensitizing agents may be appropriate; however, the
use of cardiac sensitizing agents after exposure to certain
chemicals may pose enhanced risk of cardiac arrhythmias (especially
in the elderly). Formaldehyde poisoning is not known to pose
additional risk during the use of bronchial or cardiac sensitizing
agents.
Consider racemic epinephrine aerosol
for children who develop stridor. Dose 0.25-0.75 mL of 2.25%
racemic epinephrine solution in 2.5 cc water, repeat every
20 minutes as needed, cautioning for myocardial variability.
Patients who are comatose, hypotensive,
or have seizures or cardiac dysrhythmias should be treated
according to advanced life support (ALS) protocols. Treat
acidosis with intravenous sodium bicarbonate (adult dose =
1 ampule; pediatric dose = 1 Eq/kg). Further bicarbonate therapy
should be guided by arterial blood gas (ABG) measurements.
Hemodialysis should be considered in patients with severe
acid-base disturbances that are refractory to conventional
therapy or in cases with significant methanol levels.
If evidence of shock or hypotension
is observed begin fluid administration. For adults, bolus
1,000 mL/hour intravenous saline or lactated Ringer's solution
if blood pressure is under 80 mm Hg; if systolic pressure
is over 90 mm Hg, an infusion rate of 150 to 200 mL/hour is
sufficient. For children with compromised perfusion administer
a 20 mL/kg bolus of normal saline over 10 to 20 minutes, then
infuse at 2 to 3 mL/kg/hour. Follow with administration of
dopamine (2 to 20 μg/kg/min) or norepinephrine (0.1 to
0.2 μg/kg/min), if necessary.
Transport to Medical Facility
Only decontaminated patients or patients
not requiring decontamination should be transported to a medical
facility. "Body bags" are not recommended.
Report to the base station and the receiving
medical facility the condition of the patient, treatment given,
and estimated time of arrival at the medical facility.
If formaldehyde has been ingested, prepare
the ambulance in case the victim vomits toxic material. Have
ready several towels and open plastic bags to quickly clean
up and isolate vomitus.
Multi-Casualty Triage
If possible, consult with the base station
physician or the regional poison control center for advice
regarding triage of multiple victims.
Patients who have ingested formalin or
have symptoms (e.g., severe wheezing or dyspnea) or obvious
injuries (e.g., skin or eye burns) should be transported immediately
to a medical facility for evaluation.
Patients who have no eye, skin, or throat
irritation, or only mild or transient symptoms may be released
from the scene after their names, addresses, and telephone
numbers are recorded. Those discharged should be advised to
seek medical care promptly if symptoms develop (see Patient
Information Sheet below).
Emergency Department Management
- Hospital personnel in an enclosed area can be secondarily
contaminated by direct contact, by vapors off-gassing from
heavily soaked clothing, or from the vomitus of victims
who have ingested formaldehyde. Patients do not pose serious
contamination risks after contaminated clothing is removed
and the skin is thoroughly washed.
- Inhalation of formaldehyde can cause airway irritation,
bronchospasm, and pulmonary edema.
- Absorption of large amounts of formaldehyde via any route
can cause severe systemic toxicity, leading to metabolic
acidosis, tissue and organ damage, and coma.
- There is no antidote for formaldehyde. Treatment consists
of supportive measures including decontamination (flushing
of skin and eyes with water, gastric lavage, and administration
of activated charcoal), administration of supplemental oxygen,
intravenous sodium bicarbonate and/or isotonic fluid, and
hemodialysis.
Decontamination Area
Previously decontaminated patients and
patients exposed only to formaldehyde vapor who have no skin
or eye irritation may be transferred immediately to the Critical
Care Area. Other patients will require decontamination as
described below. Because formaldehyde is absorbed (although
poorly) through the skin, don butyl rubber gloves and apron
before treating patients. Formaldehyde readily penetrates
most rubbers and barrier fabrics or creams, but butyl rubber
provides good skin protection.
Be aware that use of protective equipment
by the provider may cause fear in children, resulting in decreased
compliance with further management efforts.
Because of their relatively larger surface
area:body weight ratio, children are more vulnerable to toxicants
absorbed through the skin. Also, emergency room personnel
should examine children's mouths for corrosive injury because
of the frequency of hand-to-mouth activity among children.
ABC Reminders
Evaluate and support airway, breathing,
and circulation. Children may be more vulnerable to corrosive
agents than adults because of the smaller diameter of their
airways. In cases of respiratory compromise secure airway
and respiration via endotracheal intubation. If not possible,
surgically create an airway.
Treat patients who have bronchospasm
with aerosolized bronchodilators. The use of bronchial sensitizing
agents in situations of multiple chemical exposures may pose
additional risks. Consider the health of the myocardium before
choosing which type of bronchodilator should be administered.
Cardiac sensitizing agents may be appropriate; however, the
use of cardiac sensitizing agents after exposure to certain
chemicals may pose enhanced risk of cardiac arrhythmias (especially
in the elderly). Formaldehyde poisoning is not known to pose
additional risk during the use of bronchial or cardiac sensitizing
agents.
Consider racemic epinephrine aerosol
for children who develop stridor. Dose 0.25-0.75 mL of 2.25%
racemic epinephrine solution in 2.5 cc water, repeat every
20 minutes as needed, cautioning for myocardial variability.
Patients who are comatose, hypotensive,
or have seizures or ventricular dysrhythmias should be treated
in the conventional manner.
Correct acidosis in the patient who
has coma, seizures, or cardiac dysrhythmias by administering
intravenously sodium bicarbonate (adult dose = 1 ampule; pediatric
dose = 1 Eq/kg). Further bicarbonate therapy should be guided
by ABG measurements. Hemodialysis should be considered in
patients with severe acid-base disturbances that are refractory
to conventional therapy or in cases with significant methanol
levels.
If evidence of shock or hypotension
is observed begin fluid administration. For adults, bolus
1,000 mL/hour intravenous saline or lactated Ringer's solution
if blood pressure is under 80 mm Hg; if systolic pressure
is over 90 mm Hg, an infusion rate of 150 to 200 mL/hour is
sufficient. For children with compromised perfusion administer
a 20 mL/kg bolus of normal saline over 10 to 20 minutes, then
infuse at 2 to 3 mL/kg/hour. Follow with administration of
dopamine (2 to 20 μg/kg/min) or norepinephrine (0.1 to
0.2 μg/kg/min), if necessary.
Basic Decontamination
Patients who are able may assist with
their own decontamination.
Because contact with formalin may cause
burns, ED staff should don chemical-resistant jumpsuits (e.g.,
of Tyvek or Saranex) or butyl rubber aprons, rubber gloves,
and eye protection if the patient's clothing or skin is wet
with formalin. After the patient has been decontaminated,
no special protective clothing or equipment is required for
ED personnel.
Quickly remove and double-bag contaminated
clothing and personal belongings. Flush exposed skin and hair
with water (preferably under a shower) for 5 minutes. If possible,
wash hair and skin with soap and water, then rinse thoroughly
with water. Use caution to avoid hypothermia when decontaminating
children or the elderly. Use blankets or warmers when appropriate.
Flush exposed eyes with water or saline
for at least 15 minutes. Remove contact lenses if easily removable
without additional trauma to the eye. An ophthalmic anesthetic,
such as 0.5% tetracaine, may be necessary to alleviate blepharospasm,
and lid retractors may be required to allow adequate irrigation
under the eyelids. If pain or injury is evident, continue
irrigation while transporting the patient to the Critical
Care Area.
In cases of formalin ingestion, do
not induce emesis. If water has not been given previously,
administer 4 to 8 ounces if the patient is alert and able
to swallow. The effectiveness of activated charcoal administration
is unknown, but may be beneficial (if not administered previously)
following lavage if it can be performed within 1 hour after
ingestion (administer activated charcoal at 1 gm/kg, usual
adult dose 60-90 g, child dose 25-50 g). A soda can and straw
may be of assistance when offering charcoal to a child. (More
information is provided in Ingestion Exposure under
Critical Care Area below.)
Critical Care Area
Be certain that appropriate decontamination
has been carried out (see Decontamination Area above).
ABC Reminders
Evaluate and support airway, breathing,
and circulation as in ABC Reminders above. Children
may be more vulnerable to corrosive agents than adults because
of the relatively smaller diameter of their airways. Establish
intravenous access in seriously ill patients if this has not
been done previously. Continuously monitor cardiac rhythm.
Patients who are comatose, hypotensive,
or have seizures or cardiac dysrhythmias should be treated
in the conventional manner. Correct acidosis in the patient
who has coma, seizures, or cardiac dysrhythmias by administering
intravenously sodium bicarbonate (adult dose = 1 ampule; pediatric
dose = 1 Eq/kg). Further bicarbonate therapy should be guided
by ABG measurements. Hemodialysis should be considered in
patients with severe acid-base disturbances that are refractory
to conventional therapy or in cases with significant methanol
levels.
If evidence of shock or hypotension is
observed begin fluid administration. For adults, bolus 1,000
mL/hour intravenous saline or lactated Ringer's solution if
blood pressure is under 80 mm Hg; if systolic pressure is
over 90 mm Hg, an infusion rate of 150 to 200 mL/hour is sufficient.
For children with compromised perfusion administer a 20 mL/kg
bolus of normal saline over 10 to 20 minutes, then infuse
at 2 to 3 mL/kg/hour. Follow with administration of dopamine
(2 to 20 μg/kg/min) or norepinephrine (0.1 to 0.2 μg/kg/min),
if necessary.
Inhalation Exposure
Administer supplemental oxygen by mask
to patients who have respiratory complaints. Treat patients
who have bronchospasm with aerosolized bronchodilators. The
use of bronchial sensitizing agents in situations of multiple
chemical exposures may pose additional risks. Consider the
health of the myocardium before choosing which type of bronchodilator
should be administered. Cardiac sensitizing agents may be
appropriate; however, the use of cardiac sensitizing agents
after exposure to certain chemicals may pose enhanced risk
of cardiac arrhythmias (especially in the elderly). Formaldehyde
poisoning is not known to pose additional risk during the
use of bronchial or cardiac sensitizing agents.
Consider racemic epinephrine aerosol
for children who develop stridor. Dose 0.25-0.75 mL of 2.25%
racemic epinephrine solution in 2.5 cc water, repeat every
20 minutes as needed, cautioning for myocardial variability.
Observe patients who are in respiratory
distress for up to 12 hours and periodically repeat chest
examinations and order other appropriate studies. Follow up
as clinically indicated.
Skin Exposure
If formalin or high concentrations of
formaldehyde vapor were in contact with the skin, chemical
burns may result; treat as thermal burns.
Because of their relatively larger surface
area:body weight ratio, children are more vulnerable to toxicants
absorbed through the skin.
Eye Exposure
Continue irrigation for at least 15 minutes.
Test visual acuity. Examine the eyes for corneal damage and
treat appropriately. Immediately consult an ophthalmologist
for patients who have severe corneal injuries.
Ingestion Exposure
Do not induce emesis. Give 4 to
8 ounces of water to alert patients who can swallow if not
done previously. If a large dose has been ingested and the
patient's condition is evaluated within 30 minutes after ingestion,
consider gastric lavage and endoscopy to evaluate the extent
of corrosive injury to the gastrointestinal tract. Care must
be taken when placing the gastric tube because blind gastric-tube
placement may further injure the chemically damaged esophagus
or stomach. Extreme throat swelling may require endotracheal
intubation or cricothyriodotomy. The effectiveness of activated
charcoal in binding formaldehyde is unknown, but may be beneficial
(if not administered previously) following lavage if it can
be performed within 1 hour after ingestion (administer activated
charcoal at 1 gm/kg, usual adult dose 60-90 g, child dose
25-50 g). A soda can and straw may be of assistance when offering
charcoal to a child.
Because children do not ingest large
amounts of corrosive materials, and because of the risk of
perforation from NG intubation, lavage is discouraged in children
unless intubation is performed under endoscopic guidance.
Toxic vomitus or gastric washings should
be isolated (e.g., by attaching the lavage tube to isolated
wall suction or another closed container).
Antidotes and Other Treatments
There is no antidote for formaldehyde.
Treat patients who have metabolic acidosis with sodium bicarbonate
(adult dose = 1 ampule; pediatric dose = 1 Eq/kg). Further
correction of acidosis should be guided by ABG measurements.
Hemodialysis is effective in removing
formic acid (formate) and methanol and in correcting severe
metabolic acidosis.
If methanol poisoning from ingestion
of formalin is suspected, as indicated by a serum methanol
level of greater than 20 mg/dL or elevated osmolal gap, start
ethanol infusion. With 10% ethanol, the loading dose is 7.5
mL/kg body weight; maintenance dose is 1.0 to 1.5 mL/kg/hour;
and maintenance dose during hemodialysis is 1.5 to 2.5 mL/kg/hour.
In this setting, the target blood level of ethanol is 0.1
mg/dL.
Laboratory Tests
Routine laboratory studies for all exposed
patients include CBC, glucose, and electrolyte determinations.
Additional studies for patients exposed to formaldehyde include
urinalysis (protein, casts, and red blood cells may be present),
methanol level, osmolal gap, and ABG measurements (to monitor
acidosis in severe toxicity). Chest radiography and pulse
oximetry may be helpful in cases of inhalation exposure. Plasma
formaldehyde levels are not useful.
Disposition and Follow-up
Consider hospitalizing patients who have
evidence of systemic toxicity from any route of exposure.
Delayed Effects
Patients who have substantial ingestion
exposure may develop aspiration pneumonitis or renal failure
and should be admitted to an intensive care unit for observation.
Corrosive gastritis, fibrosis of the stomach (shrinkage and
contracture), hematemesis, or edema and ulceration of the
esophagus may occur.
Patients who have inhalation exposure
and who complain of chest pain, chest tightness, or cough
should be observed and examined periodically for 6 to 12 hours
to detect delayed-onset bronchitis, pneumonia, pulmonary edema,
or respiratory failure.
Formaldehyde poisoning can cause permanent
alterations of nervous system function, including problems
with memory, learning, thinking, sleeping, personality changes,
depression, headache, and sensory and perceptual changes.
Patient Release
Patients who are asymptomatic should
be observed for 4 to 6 hours, then discharged if no symptoms
occur during this period. Advise discharged patients to seek
medical care promptly if symptoms develop (see the Formaldehyde-Patient
Information Sheet below).
Follow-up
Obtain the name of the patient's primary
care physician so that the hospital can send a copy of the
ED visit to the patient's doctor.
Patients with symptoms of seizures,
convulsions, headache, or confusion, need to be followed for
permanent central nervous system dysfunction with neurobehavioral
toxicity testing, with particular attention to problems with
memory, personality changes, and perceptual dysfunction.
Patients with injury to the mucous membranes
of the respiratory or gastrointestinal tracts should be monitored
for the development of ulceration or fibrosis.
Patients who have corneal injuries should
be reexamined within 24 hours.
Reporting
If a work-related incident has occurred,
you may be legally required to file a report; contact your
state or local health department.
Other persons may still be at risk in
the setting where this incident occurred. If the incident
occurred in the workplace, discussing it with company personnel
may prevent future incidents. If a public health risk exists,
notify your state or local health department or other responsible
public agency. When appropriate, inform patients that they
may request an evaluation of their workplace from OSHA or
NIOSH. See Appendices III and IV for a list of agencies that
may be of assistance.
Patient Information Sheet
This handout provides information and
follow-up instructions for persons who have been exposed to
formaldehyde.
Print this handout only.pdf icon[PDF-45 KB]
What is formaldehyde?
Formaldehyde is a nearly colorless, highly
irritating gas with a sharp odor. It dissolves easily in water
and is found in formalin (a solution of formaldehyde, water,
and methanol). Formaldehyde is used in the manufacture of
plastics; urea-formaldehyde foam insulation; and resins used
to make construction materials (e.g., plywood), paper, carpets,
textiles, paint, and furniture.
What immediate health effects can be caused by exposure to formaldehyde?
Formaldehyde can cause irritation of
the eyes, nose, and throat, even at low levels for short periods.
Longer exposure or higher doses can cause coughing or choking.
Severe exposure can cause death from throat swelling or from
chemical burns to the lungs. Direct contact with the skin,
eyes, or gastrointestinal tract can cause serious burns. Drinking
as little as 30 mL (about 2 tablespoons) of formalin can cause
death. Formate, a formaldehyde metabolite, can cause death
or serious systemic effects. Generally, the more serious the
exposure to formaldehyde, the more severe the symptoms. Previously
sensitized persons may develop a skin rash or breathing problems
from very small exposures.
Can formaldehyde poisoning be treated?
There is no antidote for formaldehyde,
but its effects can be treated, and most exposed persons get
well. Patients who have had a serious exposure (with signs
and symptoms such as tearing eyes, running nose, or severe
or persistent coughing) may need to be hospitalized. Patients
with direct exposure to very concentrated vapors or liquid
or who have swallowed formalin may require intensive hospital
treatment and may experience long-term effects.
Are any future health effects likely to occur?
A single small exposure from which a
person recovers quickly is not likely to cause delayed or
long-term effects. After a severe exposure, some symptoms
may not occur for up to 18 hours. See Follow-up Instructions
for signs and symptoms to watch for. If any of them occur,
seek medical care. Long-term, repeated exposure to formaldehyde
in the workplace may cause cancer of the nasal passages.
What tests can be done if a person has been exposed to formaldehyde?
Specific tests for the presence of formaldehyde
in blood or urine may be available, but the results generally
are not useful to the doctor. If a severe exposure has occurred,
blood and urine analyses and other tests may show whether
the lungs have been injured or if systemic effects are possible.
If seizures or convulsions have occurred neurobehavioral toxicity
testing may be necessary. Testing is not needed in every case.
Where can more information about formaldehyde be found?
More information about formaldehyde can
be obtained from your regional poison control center; your
state, county, or local health department; the Agency for
Toxic Substances and Disease Registry (ATSDR); your doctor;
or a clinic in your area that specializes in occupational
and environmental health. If the exposure happened at work,
you may wish to discuss it with your employer, the Occupational
Safety and Health Administration (OSHA), or the National Institute
for Occupational Safety and Health (NIOSH). Ask the person
who gave you this form for help in locating these telephone
numbers.
Follow-up Instructions
Keep this page and take it with you to
your next appointment. Follow only the instructions
checked below.
Print instructions only.pdf icon[PDF-45 KB]
[ ] Call your doctor or the Emergency
Department if you develop any unusual signs or symptoms within
the next 24 hours, especially:
- coughing, difficulty breathing or shortness of breath
- chest pain, irregular heart beats
- increased pain or a discharge from your eyes
- increased redness or pain or a pus-like discharge in the
area of a skin burn or other wound
- fever
- unexplained drowsiness, fatigue, or headache
- stomach pain, vomiting, or diarrhea
[ ] No follow-up appointment is necessary
unless you develop any of the symptoms listed above.
[ ] Call for an appointment with Dr.____
in the practice of ________.
When you call for your appointment, please
say that you were treated in the Emergency Department at _________
Hospital by________and were advised to be seen again in ____days.
[ ] Return to the Emergency Department/Clinic
on ____ (date) at _____ AM/PM for a follow-up examination.
[ ] Do not perform vigorous physical
activities for 1 to 2 days.
[ ] You may resume everyday activities
including driving and operating machinery.
[ ] Do not return to work for _____days.
[ ] You may return to work on a limited
basis. See instructions below.
[ ] Avoid exposure to cigarette smoke
for 72 hours; smoke may worsen the condition of your lungs.
[ ] Avoid drinking alcoholic beverages
for at least 24 hours; alcohol may worsen injury to your stomach
or have other effects.
[ ] Avoid taking the following medications:
________________
[ ] You may continue taking the following
medication(s) that your doctor(s) prescribed for you: _______________________________
[ ] Other instructions:
____________________________________
_____________________________________________________
- Provide the Emergency Department with the name and the
number of your primary care physician so that the ED can
send him or her a record of your emergency department visit.
- You or your physician can get more information on the
chemical by contacting: ____________ or _____________, or by
checking out the following Internet Web sites:
___________;__________.
Signature of patient _______________ Date ____________
Signature of physician _____________ Date ____________
Where can I get more information?
If you have questions or concerns, please contact your community or state health or environmental quality department or:
For more information, contact:
Agency for Toxic Substances and Disease Registry
Division of Toxicology and Human Health Sciences
4770 Buford Highway
Chamblee, GA 30341-3717
Phone: 1-800-CDC-INFO 888-232-6348 (TTY)
Email: Contact CDC-INFO
ATSDR can also tell you the location of occupational and environmental health clinics. These clinics specialize in recognizing, evaluating, and treating illnesses resulting from exposure to hazardous substances.