BASIC ACRYLIC MONOMER MANUFACTURERS, INC.

Basic Acrylic Esters:

Background Information

ABOUT BAMM

The Basic Acrylic Monomer Manufacturers, Inc. (BAMM) is a trade association of manufacturers and importers of acrylic acid and its basic esters including butyl acrylate, ethyl acrylate, methyl acrylate and 2-ethylhexyl acrylate. BAMM current membership includes: BASF Corporation; ATOFINA Chemicals, Inc.; Celanese Ltd; Rohm and Haas Company; and The Dow Chemical Company.

ABOUT THIS SUMMARY

Basic Acrylic Monomers - acrylic acid and its esters - are versatile chemicals that have widespread use. The manufacturers, and others, have conducted scientific studies on the health and environmental effects of these products. This brochure provides a summary of technical, exposure, and regulatory information for use by government officials, health professionals, and others who would like a brief introduction to the data. This brochure includes data that BAMM is aware of as of the date of publication. BAMM has been careful to accurately summarize the data and conclusions; however, newer data may be or become available.

Users should also consult their suppliers' Material Safety Data Sheet (MSDS) for up-to-date information and precautions for safe handling and use of these chemical products.

INTRODUCTION

Acrylic acid has served, for more than 30 years, as an essential building block in the production of some of our most commonly used industrial and consumer products.

Approximately two-thirds of the acrylic acid manufactured in the United States is used to produce acrylic esters - methyl acrylate, butyl acrylate, ethyl acrylate, and 2-ethylhexyl acrylate - which, when polymerized (see below), are ingredients in paints, coatings, textiles, adhesives, plastics, and many other applications.

The remaining one-third of the acrylic acid is used to produce polyacrylic acid, or crosslinked polyacrylic acid compounds, which have been successfully used in the manufacture of hygienic products, detergents, and waste water treatment chemicals.

Polymerization

Acrylic monomers are highly reactive chemicals and, therefore, are used nearly exclusively as intermediates in the production of other materials. For example, individual molecules of acrylic acid or esters, called "monomers," readily combine with themselves or other monomers to form long chains of repeating units, or "polymers." The polymers have different physical and chemical properties than the constituent monomers.

These polymers can be used in the production of goods that for decades have provided added benefits and convenience to consumers and manufacturers worldwide.

PHYSICAL PROPERTIES

	Methyl Acrylate	Ethyl Acrylate	Butyl Acrylate	2-Ethylhexyl Acrylate
Molecular Formula	C4H602	C5H8O2	C7H12O2	C11H20O2
Molecular Weight	86	100	128	184
CAS Number	96-33-3	140-88-5	141-32-2	103-11-7
Boiling Point (°C)	80	100	148	216
Freezing Point (°C)	<-76	<-72	<-65	<-76
Density (20/20 °C)	0.957	0.923	0.900	0.886
Flash Point (Tag Closed Cup °C)	-3	8	41	87

EXPOSURE TO ACRYLIC ESTERS

Acrylate vapor has a very strong acrid odor that leads to early detection of any potential releases. The following table contains a list of current standards for levels to which the standard-setting bodies consider that most workers can be exposed during an 8-hour workday without harmful effects, as well as the results of tests used to determine the levels at which the acrylates usually will be smelled. As illustrated, acrylate odor usually will be detected before it reaches the levels of the current standards. While unpleasant, smelling acrylate vapor is not necessarily indicative that such levels have been exceeded.

	Methyl Acrylate	Ethyl Acrylate	Butyl Acrylate	2-Ethylhexyl Acrylate
OSHA Permissible Exposure Limit (ppm)	10, skin	25, skin	None	None
ACGIH Threshold Limit Value® (ppm)	2, skin, sensitizer, A4	5, A4 15 ppm STEL	2, A4, sensitizer	Not established
Odor Threshold (ppm)	0.014 to 0.020	0.00036 to 0.001	0.0001 to 0.009	0.016 to 0.18

Because consumer products contain only trace levels of acrylic esters as a result of the polymerization process, consumers are not generally exposed to these compounds in finished products. Although potential for exposure does exist during acrylic ester manufacture, transportation, and use, enclosed systems limit the exposure to worker populations and nearby communities. Employees and contractors involved in acrylic ester manufacturing should wear appropriate safety equipment and undergo special training.

In spite of the manufacturer's efforts to contain the manufacturing process, vapors can potentially escape from leaks in the piping system, during repair or replacement of the piping system (including tanks and reactors), or during removal of samples for quality control purposes. Worker exposure should be monitored in manufacturing facilities with specialized monitoring systems. Because odors will be detected at such low levels, leaks should be detected and repaired before a product can cause adverse health effects

Exposure could also occur during loading, unloading, and transportation of tank trucks, railroad tankers, barges, and drums. However, dedicated systems designed to handle acrylic esters are typically used for loading and unloading purposes and procedures should be in place to prevent spills or leaks during transportation.

TOXICOLOGY PROFILE

The likely primary routes of human exposure to the acrylic esters are skin contact and inhalation; toxicity is due to tissue damage at the site of contact. The undiluted esters are moderately irritating to corrosive liquids that can cause permanent tissue damage upon direct contact with the body. Contact with dilute solutions of the esters or monomer vapors can be irritating to the skin, eyes and respiratory tract.

In animal studies, the irritation caused by repeated exposure to acrylic esters vapor at levels exceeding the TLV® has resulted in nasal lesions. The esters have caused skin sensitization, and individuals allergic to one ester may exhibit a sensitization reaction when exposed to other esters.

In general, the esters that are absorbed are rapidly broken down in the body by two different mechanisms. The resulting metabolites are eliminated via expired air and urine.

Toxicity associated with repeated exposures of experimental animals to acrylate esters typically has been comprised of changes in body and organ weights as well as clinical chemistry. Although the National Toxicology Program has determined these results are not relevant to man, ethyl acrylate has caused tumors in animals when large doses were injected by tubes directly into the animals' forestomachs. Except for dermal and nasal lesions which have been observed at the site of contact, the microscopic examination of other body tissues post-exposure has indicated no significant difference compared to non-exposed animals.

The acute toxicity of acrylic acid to fish and invertebrates ranged from "slightly" toxic to "practically non-toxic." The acute toxicity of the acrylic esters was "moderately" toxic. Acrylic acid and the acrylic esters tested do not accumulate in the environment. If released to surface water, acrylic acid and the esters would all be rapidly biodegraded; some portion should volatilize to the air.

REGULATORY STANDARDS

The manufacture, transportation, and use of basic acrylates are regulated or addressed by a number of government agencies and other expert groups to control exposure to workers and the environment. The following table records major U.S. federal regulatory and similar information as of June 1999. Such regulations frequently change, and many states and localities adopt their own regulations. Therefore, you should consult applicable laws and regulations, as well as the manufacturer's MSDS, for current requirements.

REGULATORY STANDARDS

	Methyl Acrylate	Ethyl Acrylate	Butyl Acrylate	2-Ethylhexyl Acrylate
OSHA PEL	10 ppm, skin	25 ppm, skin	None	None
ACGIH TLV®	2 ppm, skin, sensitizer	5 ppm 15 ppm STEL	2 ppm, sensitizer	None
IARC	3	2B (Suspect Human Carcinogen)	3	None
NTP BRC	no	no	no	no
DOT Hazard Class	flammable	flammable, corrosive	flammable	no
SARA/CERCLA RQ	no	1000 lbs	no	no
SARA 313	yes	yes	yes	no
RCRA	no	yes	no	no
CAA	no	yes	no	no
CWA	no	no	no	no
FDA Uses1	yes	yes	yes	yes
NFPA Rating: 2
· Health	2	2	2	2
· Flammability	3	3	2	2
· Reactivity	2	2	2	2

 

¹ Acrylic esters used as monomer to make specific polymers are listed for certain, specific indirect food additive uses.

² NFPA Rating Definitions: 2/Health–Materials hazardous to health, but areas may be entered with full-face mask, self-contained breathing apparatus which provides eye protection; 2/Flammability–Materials that must be moderately heated before ignition will occur; 3/Flammability–Materials that can be ignited under almost all normal temperature conditions; 2/Reactivity–Materials that (in themselves) are normally unstable and readily undergo violent chemical change but do not detonate.

³ Delisted from the NTP Report on Carcinogens in May 2000

 

ACRONYM LISTING

ACGIH TLV®	American Conference of Governmental Industrial Hygienists, Threshold Limit Value®
CAA	Clean Air Act, §112(b)
CWA	Clean Water Act, §§116.4, 112 App. D, 131.36, 401.15, 423 App. A.
DOT Hazard Class	Dept. Of Transportation: Hazard Class 49 C.F.R. §172.101
FDA	Food & Drug Administration: 21 C.F.R. Parts 174 to 178
IARC	International Agency for Research on Cancer
NFPA	National Fire Protection Association
NTP RC	National Toxicology Program Report on Carcinogens
OSHA PEL	Occupational Safety and Health Administration, Permissible Exposure Limit, 29 C.F.R., Table Z, §1910.1200
RCRA	RCRA - Resource Conservation and Recovery Act, 40 C.F.R. §261.33
SARA/CERCLA RQ	Superfund Amendments and Reauthorization Act (1986), 40 C.F.R. §375/Comprehensive Environmental Response, Compensation, & Liability Act (1980), 40 C.F.R. §302.4 Reportable Quantity
SARA 313	Section 313 of Title III of SARA - Toxic Release Inventory Reporting & Community Right-To-Know, 40 C.F.R. §72.65

 

FOR MORE INFORMATION

For more information, please contact your supplier or BAMM at the following address:

17260 Vannes Court
Hamilton, VA 20158
Office: 540-751-2093
Email: e.hunt@comcast.net

NOTICE

BAMM is a nonprofit, tax-exempt incorporated association, which has developed these materials to provide general background information on acrylic acid and the basic acrylate monomers. Use of this information is voluntary and should only be undertaken after an independent review of the applicable facts and circumstances of particular situations. Users should also consult the appropriate Material Safety Data Sheet (MSDS) for up-to-date information and precautions for safe handling and use of these chemical products. Although BAMM has made all reasonable efforts to present accurate information and guidance, no guarantees or warranties, including any express or implied warranties of merchantability or fitness, are made with respect to this material by BAMM, its officers, directors, members or agents. In addition, no liability, loss or damage is assumed, and all liability for any government fines or penalties, or any other claim, demand, or loss for negligence or misconduct of any kind, is expressly disclaimed, whether direct, indirect, or consequential.