Acrylic Acid


Acrylic acid (IUPAC: prop-2-enoic acid) is an organic compound with the formula CH2=CHCO2H. It is the simplest unsaturated carboxylic acid, consisting of a vinyl group connected directly to a carboxylic acid terminus. This colourless liquid has a characteristic acrid or tart smell. [1] It is miscible with water, alcohol, ether, benzene, chloroform, and acetone. It polymerises readily in the presence of oxygen. Exothermic polymerisation at room temperature may cause acrylic acid to become explosive if confined. It is sensitive to heat and sunlight. It is also a fire hazard when exposed to heat or flame. Acrylic acid is incompatible with strong oxidisers, strong bases, strong alkalies and pure nitrogen. It may polymerise (sometimes explosively) on contact with amines, ammonia, oleum and chlorosulfonic acid, iron salts and peroxides. It may corrode iron and steel. [2]

Uses [2]

The primary use of acrylic acid is in the production of acrylic esters and resins, which are used primarily in coatings and adhesives. It is also used in oil treatment chemicals, detergent intermediates, water treatment chemicals, and water absorbent polyacrylic acid polymers. Acrylic acid is used widely for polymerisation, including production of polyacrylates. It is a monomer for polyacrylic and polymethacrylic acids and other acrylic polymers. It is used in the manufacture of plastics, as a tackifier, as a flocculant, in the production of water-soluble resins and salts, as a comonomer in acrylic emulsion and solution polymers and in moulding powder for signs, construction units, decorative emblems and insignias. It is used in polymer solutions for coatings applications, in paint formulations, in leather finishings, in paper coatings, in polishes and adhesives and in general finishes and binders.

Sources & Routes of Exposure [3,4]

Exposure can occur through inhalation, ingestion, and contact to the eyes and skin. Studies show that eye or skin irritation from exposure to acrylic acid can range in intensity from mild to severe. People can be exposed to acrylic acid through direct contact with a product containing it or by inhaling it in air contaminated by a nearby plant manufacturing acrylic acid. Exposure to acrylic acid occurs primarily in the workplace via inhalation and dermal contact during its manufacture or use. Consumers may be exposed to acrylic acid in polishes, paints, coatings, rug backings, adhesives, plastics, textiles, and paper finishes. In addition, acrylic acid may be released in wastewater and as emissions during its production and use. Individuals may be exposed by inhaling ambient air or ingesting contaminated water. Acrylic acid is also produced naturally by some species of algae.

Health Effects [4]

Potential effects of exposure to acrylic acid include:

  • Mild to moderate oral toxicity: Patients with mild ingestions may only develop irritation or grade (superficial hyperaemia and oedema) burns of the oropharynx, oesophagus or stomach; acute or chronic complications are unlikely. Patients with moderate toxicity may develop grade II burns (superficial blisters, erosions and ulcerations) are at risk for subsequent stricture formation, particularly gastric outlet and oesophageal. Some patients (particularly young children) may develop upper airway oedema.
  • Severe Oral Toxicity: May develop deep burns and necrosis of the gastrointestinal mucosa. Complications often include perforation (oesophageal, gastric, rarely duodenal), fistula formation (tracheoesophageal, aortoesophageal), and gastrointestinal bleeding. Upper airway oedema is common and often life threatening. Hypotension, tachycardia, tachypnea and, rarely, fever may develop. Other rare complications include metabolic acidosis, hemolysis, renal failure, disseminated intravascular coagulation, elevated liver enzymes, and cardiovascular collapse. Stricture formation (primarily gastric outlet and oesophageal, less often oral) is likely to develop long term. Oesophageal carcinoma is another long term complication.
  • Inhalation Exposure: Mild exposure may cause dyspnea, pleuritic chest pain, cough and bronchospasm. Severe inhalation may cause upper airway oedema and burns, hypoxia, stridor, pneumonitis, tracheobronchitis, and rarely acute lung injury or persistent pulmonary function abnormalities. Pulmonary dysfunction similar to asthma has been reported.
  • Ocular Exposure: Ocular exposure can produce severe conjunctival irritation and chemosis, corneal epithelial defects, limbal ischemia, permanent vision loss and in severe cases perforation.
  • Dermal Exposure: A minor exposure can cause irritation and partial thickness burns. More prolonged or a high concentration exposure can cause full thickness burns. Complications may include cellulitis, sepsis, contractures, osteomyelitis and systemic toxicity.
  • Chronic Exposure: Animals exposed via chronic inhalation have developed lethargy, weight loss, kidney abnormalities, embryotoxicity, and inflammation to the upper respiratory tract and gastric mucosa.

The International Agency for Research on Cancer states acrylic acid is embryotoxic and teratogenic, having the ability to adversely affect the growth or development of the embryo. However the US Environmental Protection Agency and other agencies state that no information is available to substantiate these conclusions. Tests done on rats found acrylic acid to be both embryotoxic and teratogenic. Acrylic acid is not classifiable as a human carcinogen.

Safety [5]

Fist Aid Measures

  • Eye Contact: Check for and remove any contact lenses. In case of contact, immediately flush eyes with plenty of water for at least 15 minutes. Cold water may be used. Get medical attention immediately.
  • Skin Contact: In case of contact, immediately flush skin with plenty of water for at least 15 minutes while removing contaminated clothing and shoes. Cold water may be used. Wash clothing before reuse. Thoroughly clean shoes before reuse. Get medical attention immediately.
  • Serious Skin Contact: Wash with a disinfectant soap and cover the contaminated skin with an anti-bacterial cream. Seek immediate medical attention.
  • Inhalation: If inhaled, remove to fresh air. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical attention immediately.
  • Serious Inhalation: Evacuate the victim to a safe area as soon as possible. Loosen tight clothing such as a collar, tie, belt or waistband. If breathing is difficult, administer oxygen. If the victim is not breathing, perform mouth-to-mouth resuscitation. WARNING: It may be hazardous to the person providing aid to give mouth-to-mouth resuscitation when the inhaled material is toxic, infectious or corrosive. Seek immediate medical attention.
  • Ingestion: Do NOT induce vomiting unless directed to do so by medical personnel. Never give anything by mouth to an unconscious person. Loosen tight clothing such as a collar, tie, belt or waistband. Get medical attention if symptoms appear.

Handling & Storage

  • Keep locked up
  • Keep container dry
  • Keep away from heat
  • Keep away from sources of ignition
  • Ground all equipment containing material
  • Do not ingest or breathe gas/fumes/ vapour/spray
  • Never add water to this product
  • Keep away from incompatibles such as oxidising agents, acids, alkalis, moisture
  • Store in a segregated and approved area
  • Keep container in a cool, well-ventilated area
  • Keep container tightly closed and sealed until ready for use

Exposure Controls & Personal Protection

  • Engineering Controls:

  • Provide exhaust ventilation or other engineering controls to keep the airborne concentrations of vapours below their respective threshold limit value.

  • Ensure that eyewash stations and safety showers are proximal to the work-station location.
  • Personal Protection:

  • Face shield

  • Full suit
  • Vapour respirator (be sure to use an approved/certified respirator or equivalent)
  • Gloves
  • Boots

Personal Protection in Case of a Large Spill:

  • Splash goggles
  • Full suit
  • Vapour respirator
  • Boots
  • Gloves
  • A self contained breathing apparatus should be used to avoid inhalation of the product.
  • Suggested protective clothing might not be sufficient; consult a specialist BEFORE handling this product.

Regulation [5]

  • Exposure Limits

  • TWA: 2 (ppm) from ACGIH (TLV) [United States] [1997]

  • TWA: 2 [Australia] STEL: 20 (ppm)
  • TWA: 10 (ppm) [United Kingdom (UK)]