International Journal of Oral & Maxillofacial Pathology. 2011;2(2):13-19 ISSN 2231 – 2250 Available online at http://www.journalgateway.com or http://www.ijomp.org ©2011 International Journal of Oral and Maxillofacial Pathology. Published by Publishing Division, Celesta Software Private Limited. All Rights Reserved Review Article A silent killer in the laboratory – Formaldehyde: Review of effects and management Jayalakshmi K, Ravikumar H, Jaya Naidu, Raju Raghavendra Abstract Despite the known toxicity of formaldehyde and its potential health effects, laboratory workers and others have little enthusiasm for reducing or replacing the formaldehyde working solution. The responsibility of preventing health hazards is by both management and laboratory workers. It is the responsibility of the laboratory workers to understand and adopt good laboratory practices to achieve a healthy environment. It is important to have good toxicological and inflammability profiles that permit the safe use of formaldehyde. The aim of this review is to summarize the various applications, potential hazards and management of formaldehyde effects in the laboratories. Key words: Biohazards; Formaldehyde; Osha; Biological Waste Disposal; Pathological; Jayalakshmi K, Ravikumar H, Jaya Naidu, Raju Raghavendra. A silent killer in the laboratory – Formaldehyde: Review of effects and management. International Journal of Oral & Maxillofacial Pathology; 2011:2(2):13-19. ©International Journal of Oral and Maxillofacial Pathology. Published by Publishing Division, Celesta Software Private Limited. All Rights Reserved. Received on: 22/03/2011 Accepted on: 11/06/2011 Introduction Communication standard is the Occupational Safety and Health Administration (OSHA) regulation that requires evaluation and communication to employees of all chemical hazards in the work place. OSHA and Centre for Disease Control and prevention (CDC) in 1970 gave safety regulations for clinical laboratories with numerous safety standards in a clinical set up. 1 They insisted that each employee who works with or around hazardous chemicals must receive information about those chemicals through a comprehensive training program. Chemical manufacturers are required to evaluate product hazards and should alert customers. Those informed employees can more effectively participate in, and support the protective measures instituted in their workplaces. Hazard communication programs are also commonly referred to as “Right-to-know” programs. 2 The OSHA Formaldehyde Standard was written to protect employees who came into contact with formaldehyde. The formaldehyde standard is in addition to the provisions of the hazard communication standard covering exposures to all hazardous chemicals or substances. The fact that formaldehyde is the subject of its own federal regulation should emphasize the need to protect employees from exposure. 3 Formaldehyde is a flammable, colorless gas with a pungent, suffocating odor. It is highly soluble in water (up to 55%), acetone, benzene, chloroform, diethyl ether and ethanol. The gas is stable in the absence of water but it is incompatible with oxidizers, alkalis, acids, phenols and urea. Explosive reactions occur with peroxide, nitrogen oxide, and performic acid. Anhydrous gaseous formaldehyde is not available commercially. Aldehyde groups are chemically and biologically reactive and are responsible for many histochemical reactions, e.g. free aldehyde groups may be responsible for argentaffin reactions. Pure formaldehyde is a vapor that when completely dissolved in water forms a solution containing 37-40% formaldehyde: this aqueous solution is known as „formalin‟, with 0.5% to 15% methanol as a polymerization inhibitor. 2 Formaldehyde in its 10% neutral buffered form (NBF) is the most common fixative used in diagnostic pathology. The usual „10% formalin‟ used in fixation of tissues is a 10% solution of formalin, i.e., it contains about 4% weight to volume of formaldehyde. The reactions of formaldehyde with macromolecules are numerous complexes. In an aqueous solution formaldehyde forms methylene hydrate, a methylene glycol as the first step in fixation. 4 Methylene hydrate reacts with several side chains of proteins to form reactive hydroxymethyl side groups (-CH2-OH). 4 Formaldehyde also reacts with nuclear proteins and nucleic acids. It penetrates