Monograph of Inhibited Glycol

General Information:

Inhibited glycol or propylene glycol is an organic double alcohol with a chemical formula of C3H8O2 and a CAS number of 57-55-6. Its official IUPAC name is propane-1,2-diol. It is a thick, clear, and nearly odorless substance with a faintly sweet taste. Propylene glycol shares similarities with glycerin - hygroscopic, soluble with water, acetone, and chloroform.

Physical Properties:

Molecular mass:                            76.10 g/mol
Melting point:                                -59° C
Boiling point:                                187.6° C
Vapor pressure:                             0.2 (23° C)
Vapor density:                               2.62 (air=1)
Viscosity:                                    91.41 cp (10.45° C)
Surface tension:                           40.1 g/s2 (25° C)
Refractive index:                            1.4324 (20° C)
Heat of vaporization:                    66.27 kJ/mol
Heat of combustion:                     -1828 kJ/mol

Production:

Propylene glycol is usually sourced from either propylene oxide through hydrolysis, or glycerol. Production is more or less similar with glycerin, using either catalytic (150°-180°C) or non-catalytic high-temperature process (200°-220°C). Propylene glycol is manufactured using ion exchange resin or a
small amount of sulfuric acid or alkali. Final products include 20% propylene glycol, 1.5% dipropylene glycol, and other polypropylene glycols. Then, resulting glycols are further distilled to be purified prior to storage and distribution. To assure high quality and compliance with hygienic standards, production is monitored and controlled through a track-and-trace system from the start of process up to delivery point.

References:

Wikipedia - http://en.wikipedia.org/wiki/Propylene_glycol

University of Akron Chemical Database - http://ull.chemistry.uakron.edu/erd/Chemicals/8000/
7709.html

Cefic - http://www.propylene-glycol.com/production.html

First Aid Treatment for Inhibited Glycol Exposure

Inhibited glycol is a non-poisonous substance and is considered safe by the US FDA standards for industrial use. However, exposure to large amounts and improper handling can pose serious health risks. Following precautions and application of proper first aid treatment are of paramount importance to ensure safety.

Eyes:

Liquid and/or vaporized inhibited glycol may cause mild eye irritation. If  exposure causes redness and stinging sensation, wash eyes with cold, running water for at least 15 minutes to soothe. Occasionally lift both eyelids to wash thoroughly.

Skin:

Glycol may be absorbed through damaged skin. Remove any tainted clothing and wash exposed skin areas with plenty of soap and water until irritation subsides. Apply an antibacterial cream if exposed areas develop rashes. Wash clothing well before reuse.

Ingestion:

Consumption of small amounts poses no grave danger, but intake of greater than 3-4 oz. (or approximately 100 ml.) can cause stomach pain, nausea, or even vomiting. Medical assessment may reveal hemoglobinuric nephrosis and surface changes in EEG, especially for people with kidney problems. Long-term ingestion can cause lactic acidosis and seizures.

In case of ingestion, give two to four glasses of water or milk to dilute the substance (but do not give anything by mouth to an unconscious person). It is very important NOT to induce vomiting. Instead, call the local poison control center to mitigate the problem and to get proper guidance. Victim should be monitored constantly for signs of acidosis and central nervous system  dysfunction.

Inhalation:
Inhibited glycol poses low respiratory hazards but can cause breathing difficulties and respiratory tract irritation if used in areas with poor ventilation. Because of its low vapor pressure at room temperature, vapor exposure is unlikely to happen. If inhaled, transfer victim immediately in areas with fresh, circulating air. Supplement with artificial oxygen if symptoms persist. Seek medical help immediately.

References:

Material Safety Data Sheet (MSDS) of Biopropylene Glycol. (2008, July 7). BioPG MSDS. Retrieved June 20, 2011, from www.globalbiochemna.com/uploads/BioPG_MSDS.pdf

Propylene Glycol. (2010, September 24). HordeNet at The University of Akron. Retrieved June 20, 2011, from http://ull.chemistry.uakron.edu/erd/Chemicals/8000/7709.html