(Chemical and Enzymatic)Potential Problem Areas

Chemical burns Dispensing methods Chemical reactions producing heat, gas eruptions, and/or toxic gases

Product labeling and packaging Selection of protective methods Piping/fixture failures Proper maintenance

Introduction

Chemical and enzymatic drain cleaners are often added to plumbing systems to remove an obstruction or restriction, or to prevent and/or inhibit their formation. These blockages are often the result of an accumulation of human wastes, hair, paper products, grease, soap, and other foreign materials. Such materials are normally deposited in drains, pipes, and sewer lines, but the design of piping systems, the quantity of material(s) introduced into the line, and flow problems allow the occurrence of blockages.

Chemical and enzymatic drain cleaners have the appeal of being potentially easy to use, quick in their degradation of the blockage, and often are less expensive than mechanical drain cleaning equipment. Chemical cleaners work via their reactive chemical nature; enzymatic cleaners work via slower biological/digestive type reactions. Because of their chemical reactivity, coupled with the often unknown contents and configurations of plumbing systems, improper application of chemical drain cleaners can result in unexpected chemical reactions, splashes, and other effects which may result in personal injury and/or property damage.

Classifications

Drain cleaners may be categorized into four major groups, which include:

Acids (e.g., sulfuric acid, hydrochloric acid, ...) Oxidizers (e.g., sodium hypochlorite, ...) Caustics (e.g., caustic soda, lye, sodium hydroxide, ...)  Enzymatic (e.g., organisms or biochemicals which consume or digest particular waste materials)

Implications

Removal of pipeline obstructions or restrictions may be performed by mechanical or chemical removal methods. Chemical removal methods rely upon generation of heat and reaction between the drain cleaner and blockage material(s). These reactions may be of different mechanisms, but have potential to be vigorous and liberate gases. Chemicals may cause burns, react with materials other than those in the blockage, and produce other undesirable physical effects. Chemical drain cleaners may damage plumbing and surrounding surfaces. Chemical drain cleaners are generally more dense than water and tend to sink to a lowest possible point. Enzymatic drain cleaners are less likely to acutely harm the human body by direct contact with the skin and/or eyes than chemical drain cleaners. Reformulations and introduction of slower reacting methods have reduced the potential for some hazards at the expense of the potential loss of effectiveness in dissolving the blockage material(s).

Reactions And Incompatibilities

• The heat liberated by chemical drain cleaners may soften plastic (PVC) pipes. Combined heat and chemical reaction may damage old, corroded pipes. Acid drain cleaners can corrode or etch stainless steel, damage aluminum fixtures, and (by heat of solution) may crack porcelain. If a chemical drain cleaner does not remove the obstruction in the piping system, the chemical may remain unreacted in the piping system. Users occasionally attempt to clear a blockage by using more than one product. The introduction of acid drain cleaners into pipes containing caustic drain cleaners may result in vigorous acid-base neutralization reactions. These reactions generally result in the formation of a salt and water, but may generate extreme heat and, consequently, the liquids may spatter or erupt from the drain. Dilution of concentrated caustics and acids may also generate heat. This "heat of solution" may be considerable and variable, depending on the initial and final solution concentrations. If the chemical remains unreacted in the piping system, persons subsequently attempting to clear the blockage by mechanical means may unknowingly have potential of exposure to the chemical.

• The addition of water to a concentrated caustic or acid may also result in boiling and spattering of the resulting solution; if the caustic or acid is slowly and carefully added to water, this effect is minimized. Standards often recommend using the term "concentrated" for aqueous solutions as a warning for potential health effects or injuries to tissue. However, chemical texts often use the same term for nearly pure solutions.

• Reactions which generate gases may result in pressure buildup and possible eruptions because of volumetric differences between liquids and gases. The mixing of caustic acid drain cleaners containing sodium hypochlorite with other household chemicals may result in the generation of toxic gases such as chloramine or chlorine. The oxidation of organic materials may result in the formation of gases such as carbon dioxide, hydrogen, and/or organic gases. Carbonates in concrete and acid drain cleaners may react to liberate carbon dioxide gas. Enzymatic treatments generally require at least one overnight application, during which the drain cannot be used. Most treatments require additional applications in order to establish a colony; because bacteria are regularly washed out as the drain is used, such treatments recommend monthly maintenance applications. Addition of bleach, disinfectants, solvents, or other chemicals may be harmful to the established bacterial colony. 12

Conclusion

Chemical and enzymatic drain cleaners are potentially dangerous to use. They are reactive with human tissue in a similar manner as to the organic materials in drain blockages. Hazardous and toxic gases may be generated, as well as spattering and/or eruptions. Standards exist addressing these potential hazards with recommendations for proper and safe use, packaging and labeling recommendations, and personal protection recommendations. Recommendations have been made to use preventive methods such as avoiding pouring grease down drains; using strainers to trap food, hair, and other articles; regular biological/enzymatic treatments; and/or, pouring hot water down the drain weekly to keep the drain free flowing. (The water should be poured directly into the drain rather than in the basin, so as to avoid cracking of porcelain fixtures). If a drain requires cleaning, consumer advocates recommend the use of mechanical devices, followed by removal and cleaning of traps and cleanout plugs. Chemical cleaners are recommended only as a last resort; if the chemical drain cleaner fails to work, a professional should be contacted and the situation should be explained. 13,14

References

http://www.meridianeng.com/draincle.html This is not a Material Safety Data Sheet, but rather a Reference Data Sheet that has been compiled from a number of sources, and is intended to be a concise, relatively non-technical source of information on a particular material or category of materials. It is provided in good faith and is believed to be correct as of the date compiled; however, Meridian Engineering & Technology makes no representation as to the comprehensiveness or accuracy of the information. It is expected that individuals receiving the information will exercise their independent judgment in determining its appropriateness for a particular purpose. Accordingly, Meridian Engineering & Technology will not be responsible for damages of any kind resulting from the use of or reliance upon such information.