Formaldehyde-Applications in Textiles and Alternatives Kazy Mohammad Iqbal Hossain
What is it? Formaldehyde is a naturally-occurring organic compound with the formula CH2O. It is the simplest aldehyde and is also known by its systematic name methanal. The common name of this substance comes from its similarity and relation to formic acid. A gas at room temperature, formaldehyde is colorless and has a characteristic pungent, irritating odor. It is an important precursor to many other materials and chemical compounds. In 1996, the installed capacity for the production of formaldehyde was estimated to be 8.7 million tonnes per year. Commercial solutions of formaldehyde in water, commonly called formol or formalin, were formerly used as disinfectants and for preservation of biological specimens. It is also used for the embalming of human remains. It is commonly used in nail hardeners and/or nail varnish.
Uses in Textiles Formaldehyde can be found in screen-print inks, and textile finishes, especially resins for wrinkle resistance and anti-shrinking. For years the textile industry has been using finishes on fabric that
prevents wrinkling – usually a formaldehyde resin. Fabrics are treated with urea-formaldehyde resins to give them all sorts of easy care properties such as: • Permanent press / durable press • Anti-cling, anti-static, anti-wrinkle, and anti-shrink (especially shrink proof wool) • Waterproofing and stain resistance (especially for suede and chamois) • Perspiration proof • Moth proof • Mildew resistant • Color-fast According to the American Contact Dermatitis Society, rayon, blended cotton, corduroy, wrinkleresistant 100% cotton, and any synthetic blended polymer are likely to have been treated with formaldehyde resins. The types of resins used include urea-formaldehyde, melamine-formaldehyde and phenol-formaldehyde. Manufacturers often “hide” the word “formaldehyde” under daunting chemical names. These include: • • • • • •
Formalin Methanal Methyl aldehyde Methylene oxide Morbicid acid Oxymethylene
Not only is formaldehyde itself used, but also formaldehyde-releasing preservatives. Some of these are known by the following names: • • • •
Quaternium-15 2-bromo-2nitropropane-1,3-diol imidazolidinyl urea diazolidinyl urea
Impacts on Human Health Formaldehyde is highly toxic to all animals, regardless of method of intake. Ingestion of 30 mL (1 oz.) of a solution containing 37% formaldehyde has been reported to cause death in an adult human. Water solution of formaldehyde is very corrosive and its ingestion can cause severe injury to the upper gastrointestinal tract. Occupational exposure to formaldehyde by inhalation is mainly from three types of sources: thermal or chemical decomposition of formaldehyde-based resins, formaldehyde emission from aqueous solutions (for example, embalming fluids), and the production of formaldehyde resulting from the combustion of a variety of organic compounds (for example, exhaust gases). Formaldehyde can be toxic, allergenic, and carcinogenic. Because formaldehyde resins are used in many construction materials it is one of the more common indoor air pollutants. At concentrations above 0.1 ppm in air formaldehyde can irritate the eyes and mucous membranes, resulting in watery eyes. Formaldehyde inhaled at this concentration may
cause headaches, a burning sensation in the throat, and difficulty breathing, and can trigger or aggravate asthma symptoms
Alternatives
Alternatives are available for resins, adhesives, binders and other textile or leather auxiliaries which are low or no formaldehyde containing. Factories should contact their chemical suppliers to verify chemical components. They should also apply controls to protect workers using formaldehyde containing products and prevent cross contamination of products within a facility.