Example – Acrolein
This month our example is Acrolein,
which has a chemical formula of CH2=CHCHO.
Acrolein has a United Nations Shipping# of 1092 and
Chemical Abstract Service # of 107-02-8. Acrolein is a
clear, colorless, or yellow liquid with a pungent,
suffocating odor. It is very flammable and may
polymerize violently. Acrolein should be stored in a
cool, dry, well-ventilated area in tightly sealed
containers separated from alkaline materials such as
caustics, ammonia, organic amines, or mineral acids,
strong oxidizers, and oxygen. Acrolein is soluble in
water, alcohol, ether, and acetone.
Persons exposed only to Acrolein
vapor do not pose secondary contamination risks. Persons
whose clothing or skin is contaminated with liquid
Acrolein can contaminate others by direct contact or
At room temperature, Acrolein is a
clear, colorless to straw-colored liquid with a pungent,
suffocating odor. It is highly flammable and burns to
produce toxic gases (peroxides and oxides of carbon). It
is volatile, producing toxic concentrations at room
temperature. Vapors may travel to a source of ignition
and flash back. The odor of Acrolein may not provide
adequate warning of hazardous concentrations.
Acrolein is toxic by all exposure
routes. Exposure causes inflammation and irritation of
the skin, respiratory tract, and mucous membranes.
Delayed pulmonary edema may occur after inhalation.
Systemic effects may occur after exposure by any route.
Acrolein is produced by oxidation of propylene. Acrolein
is principally used as a biocide to control plants,
algae, mollusks, fungi, rodents, and microorganisms, for
example in recirculation cooling systems. Acrolein has
also been used in the manufacture of other chemicals, as
a warning agent in gases, as a test gas for gas masks,
in military poison gases, in the manufacture of
colloidal metals, in leather tanning, and as a fixative
Synonyms include 2-propenal,
2-propen-1-one, prop-2-en-1-al, acraldehyde,
acrylaldehyde, acrylic aldehyde, allyl aldehyde,
ethylene aldehyde, aqualine.
Inhaled Acrolein is highly toxic. Acrolein is
irritating to the upper respiratory tract even at low
concentrations. Its odor threshold of 0.16 ppm is
similar to the OSHA permissible exposure limit (0.1
ppm); thus odor may provide an adequate warning of
potentially hazardous concentrations. Acrolein vapor is
heavier than air, but asphyxiation in enclosed, poorly
ventilated, or low-lying areas is unlikely due to its
exposed to the same levels of Acrolein vapor as adults
may receive a larger dose because they have greater lung
surface area:body weight ratios and higher 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
Acrolein vapor found nearer to the ground.
Contact Direct contact with liquid Acrolein causes
rapid and severe eye and skin irritation or burns.
Exposure to vapor produces inflammation of mucous
membranes and it is a potent lacrimator.
their relatively larger surface area:body weight ratio,
children are more vulnerable to toxicants affecting the
Acrolein produces chemical burns of the lips, mouth,
throat, esophagus, and stomach. Nausea, vomiting, and
diarrhea also occur.
Clear, colorless to yellow liquid.
properties: Suffocating, pungent odor at 0.16 ppm.
weight: 56.06 daltons
point (760 mm Hg): 126.5 °F (52.5 °C)
point: -126 °F (-88.0 °C)
pressure: 210 mm Hg at 68 °F (20 °C)
density: 1.94 (air = 1)
gravity: 0.84 (water = 1)
solubility: 208 g/L at 20 °C
point: -15 °F (-26.1 °C)
range: 2.8% to 31% (concentration in air)
Standards and Guidelines
(permissible exposure limit) = 0.1 ppm as an 8-hr
concentration and 0.3 ppm as a 15-minute TWA short-term
exposure limit (STEL).
(immediately dangerous to life or health) = 2 ppm.
ERPG-2 (maximum airborne concentration below which it is
believed that nearly all persons could be exposed for up
to 1 hour without experiencing or developing
irreversible or other serious health effects or symptoms
that could impair their abilities to take protective
action) = 0.5 ppm.
Acrolein reacts with caustics, ammonia, organic
amines, or mineral acids, strong oxidizers, and oxygen.
Acrolein is severely irritating to
skin, eyes, and mucous membranes. Inhalation of Acrolein
may result in respiratory distress and delayed pulmonary
edema. Contact with the skin or eyes produces irritation
and lacrimation, and can result in chemical burns.
The mechanism by which Acrolein
produces toxic symptoms is not known, but the compound
is highly reactive. No information was found as to
whether the health effects of Acrolein in children are
different than in adults. Exposure to Acrolein produces
severe respiratory problems and individuals with
pre-existing breathing difficulties or skin disease may
be more susceptible to its effects.
Exposure: The mechanism by which Acrolein produces
toxic symptoms is not known, but the compound is highly
reactive, cross-links DNA, and inhibits the activities
of some enzymes (including cytochrome P450 and
glutathione-S-transferase) in vitro by reacting
with sulfhydryl groups at the active sites. It has also
been shown to suppress pulmonary antibacterial defenses,
to release oxygen radicals, and to react with proteins.
Onset of irritation is immediate, but pulmonary edema
may be delayed and respiratory insufficiency may persist
for up to 18 months after exposure.
do not always respond to chemicals in the same way that
adults do. Different protocols for managing their care
may be needed.
Acrolein produces irritation of the respiratory
tract, increases airway resistance and tidal volume, and
decreases respiratory frequency. It is also ciliastatic.
Exposure to Acrolein vapor concentrations as low as 10
ppm can lead to pulmonary edema and death. Inhalation
may also cause an asthmatic reaction in sensitized
is a weak sensitizer.
may be more vulnerable because of higher minute
ventilation per kg of body weight and failure to
evacuate an area promptly when exposed.
Acrolein is a skin irritant. Contact with the liquid
may cause skin burns, erythema, and edema.
their relatively larger surface area:body weight ratio,
children are more vulnerable to toxicants affecting the
liquid or vapor can cause eye irritation and damage to
Acrolein causes burns of the lips, mouth, throat,
esophagus, and stomach. Nausea, vomiting, and diarrhea
have been reported. No data were located as to whether
ingestion leads to systemic toxicity in humans.
inhalation may cause hypertension and tachycardia.
CNS Serious poisoning may
cause CNS depression.
Acrolein may have the potential to be immunotoxic.
The immune system in children continues to develop after
birth, and thus children may be more susceptible to
Potential Sequelae Respiratory
insufficiency may persist for up to 18 months after
Exposure: Apart from rare cases of sensitization, no
adverse effects in humans chronically exposed to low
concentrations of Acrolein have been reported.
exposure may be more serious for children because of
their potential for a longer latency period.
The Department of Health and Human Services has
determined that Acrolein may possibly be a human
carcinogen. The International Agency for Research on
Cancer has determined that Acrolein is not classifiable
as to its carcinogenicity to humans.
and Developmental Effects No studies were
located that address reproductive or developmental
effects of Acrolein in humans. Acrolein caused
developmental effects when injected into rats, but did
not cause developmental effects when ingested by
rabbits. No information was found as to whether Acrolein
crosses the placenta, but it has been measured in breast
is not included in Reproductive and Developmental
Toxicants, a 1991 report published by the U.S.
General Accounting Office (GAO) that lists 30 chemicals
of concern because of widely acknowledged reproductive
and developmental consequences.
Using the PEAC
In using the PEAC application we
access information for the chemical by first locating
Acrolein in the database. The following figures show the
screens displayed for chemical properties, Figure 1 for
the PEAC-WMD for Windows application. Last month
we started demonstrating some of the features coming out
in the new release. The screens captured from the
Windows version are from the new release. The Pocket PC
version is not quite finished, so the author has not
included figures from that version.
Figure 1 - Using the Lookup By:
Name for Acrolein using the PEAC-WMD for
One of the features of the new
release is the inclusion of hyperlinks in the text
display fields. In this case the ERG Guide number and
name are displayed as a hyperlink. If the user clicks on
the hyperlink, the ERG Guide or “orange pages” will be
displayed in the Data Display Box (Figure 2). If
the material has an entry in the “green pages” of the
ERG, this will be displayed at the top of the Data
Display Box above the “orange pages”. Acrolein is an
example of such a material as shown in Figure 2. As
shown in Figure 1, the Guide number is prefaced by a
“P”, meaning the material may polymerize explosively
when heated or involved in a fire.
Figure 2 – Displaying the ERG Guide
information after clicking on the
An advantage of using the PEAC tool
is assistance in the development of an evacuation zone
for those chemicals that produced a toxic vapor cloud.
As with all of our examples, AristaTek creates a
scenario for a spill or release of the specific chemical
and then we work through the development of a PAD
(Protective Action Distance) to demonstrate how the PAD
calculation portion of the PEAC system works. For our
scenario using Acrolein as the spilled chemical we’ll
use a chemical manufacturing facility in Denver CO. It’s
1:40 PM on Sept 10th , the temperature is
about 80°F, the winds are 5 mph, and it’s a sunny day
with no clouds. A storage tank (8’ x 25’) in the
facility that contains Acrolein has lost most of its
contents. Fortunately the Acrolein storage the tank and
surrounding tanks are contained by a 50’ x 50’ dike
around the tanks that has contained the leaking
material. Upon arrival at the scene the HAZMAT response
team observes the tank and the liquid pool. A concern is
how far to evacuate personnel and the public to prevent
inhalation of the toxic material. Another concern is how
far to evacuate with regards to the potential
flammability of the material.
As seen at the top of the data
display screens, there is a yellow icon displayed, this
is the PEAC icon for notifying the user that a
Protective Action Distance can be calculated. Clicking
on the PAD icon will display a screen as shown in Figure
3. Following through the screens, we provide information
on the Meteorology, Container Size, and Type of Release
(Source). The last screen displays the PAD based on the
It’s Denver in September and the
temperature about 80°, wind is set for 5 mph, no
clouds and the terrain is Urban/Forest since it’s
an urban setting (manufacturing facility).
We have selected from our list of
container sizes the Large Storage selection
and filled in the dimensions of the tank.
Since the scenario has most of the
contents released we’ll use a Large Rupture
and specify the size of the liquid pool as the
size of the dike area around the storage tanks.
Figure 3 – Calculating a PAD using the
After specifying the release or
source is a Large Rupture and specifying the size
of the liquid pool (this is because the Acrolein has a
boiling point of 127°F and should be a liquid when
released from the tank) the user taps the right arrow at
the top of the screen and the PAD computation results
are displayed, see Figure 4.
Figure 4 - The PEAC computation for PAD using
This PAD (Protective Action Distance)
is based on the default Level of Concern or the
IDLH, which is 2 ppm. The user may want to go with a
more conservative value like the ERPG-2, which is 0.5
ppm as shown in Figure 5. The results for this PAD are
shown in Figure 6.
Figure 5 – Selecting a different Level of
Concern from the drop-down menu
Figure 6 -
The PEAC computation for PAD using the ERPG-2
PADs are only looking at the toxicity aspect and not the
flammability issues related to Acrolein. A quick check
of the DOT ERG “orange pages” indicates a proper
evacuation distance for Guide Number 131 when a fire may
be involved is ˝ mile if a railcar or tank truck are
involved, see Figure 7. While our scenario is not a
railcar or tank truck, the volume is close enough that
to be safe we would want to move the public back at
least that distance in case the vapor cloud was to
Figure 7 –
Additional guidelines if a fire was involved
Portions of this discussion on
Acrolein were adapted from the ATSDR Medical Management
Guideline document, which can be downloaded from the
ADSTR web site at: http://www.atsdr.cdc.gov/mmg.html.