Alternatives for significant uses of formaldehyde in Massachusetts
In July 2005, the Commonwealth of Massachusetts requested that the Toxics Use Reduction Institute perform an alternatives assessment for five chemicals. For each chemical, the Institute was charged with identifying significant uses in manufacturing, consumer products, and other applications; reviewing health and environmental effects; and evaluating possible alternatives. The results of this study will serve as a guide for those seeking safer substitutes to the five chemicals discussed here.
Presented here is an executive summary of the findings of for high priority uses of formaldehyde in Massachusetts. The full report, the Five Chemicals Alternatives Assessment Study available from the link below, presents extensive factual information on each alternative
Formaldehyde is a naturally occurring chemical found in small quantities in the human body. Products that are made from or contain formaldehyde include many resins, permanent press fabric treatments, lawn fertilizers, cosmetics and disinfectants. Wood adhesives used to make plywood, particleboard and other manufactured wood products are the dominant end use for this chemical. The plastics industry also uses formaldehyde-based resins extensively. Formaldehyde is also used as a sterilant and tissue preservative. It is used to preserve animal specimens used in secondary school and college biology classes. It is also used to preserve human and animal tissue in medical and scientific laboratory settings. Embalmers use formaldehyde to preserve human remains for burial.
Formaldehyde exposure through consumer products or industrial activity is very hazardous to human health. Formaldehyde is highly irritating, acts as a potent sensitizer, and is known to cause cancer in humans. In 2004 the International Agency for Research on Cancer (IARC) moved formaldehyde from Group 2A (probable human carcinogen) to Group 1 (known human carcinogen). Ingestion of formaldehyde or exposure to very high air concentrations can cause death.
The Institute assessed alternatives to formaldehyde in three categories of use: sanitary storage in barbering and cosmetology, preserved educational specimens for dissection, and building panels.
Sanitary storage in barbering and cosmetology
The Massachusetts Board of Cosmetology requires cosmetology salons to use dry sanitizer made from para-formaldehyde (a polymerized solid form of formaldehyde) in drawers where instruments are stored. The perforated plastic containers containing para-formaldehyde emit formaldehyde as it de-polymerizes into formaldehyde gas, filling the cabinets and drawers where hair brushes are kept, and subsequently entering the salon and classroom [[indoor air|air as drawers are opened. Use of this dry sanitizer has placed a consistent source of formaldehyde in salons and cosmetology training schools, including vocational high schools. The Institute identified and evaluated two possible alternatives to the use of dry sanitizer in drawers. The first option is a process change: storage of implements in a disinfected, dry, covered container or drawer without the use of any additional sterilant. The second option is to use ultraviolet (UV) light cabinets for sanitary storage.
The Massachusetts Board of Cosmetology is the only such board in the U.S. that requires use of dry sterilants. In contrast, the National-Interstate Council of State Boards of Cosmetology (NIC) does not recommend use of formaldehyde-based dry sterilants due to their carcinogenic potential. In place of dry sterilants, the NIC recommends an alternative procedure of proper cleaning, wet disinfection, drying and storage. The disinfection and storage practices recommended by the NIC are reiterated in the rules of many other Boards of Cosmetology and in the field’s primary textbook and practice guidance.
One practical alternative to use of dry sterilant is simply to store implements in a disinfected, dry, covered container that is isolated from contaminants. This option would produce cost savings, because it would eliminate the need for cosmetology salons to purchase dry sterilant.
Simple elimination of dry sterilant, without any other change in procedures, is superior to use of dry sterilant from the human health, environmental, and cost perspectives. It is equivalent from a technical perspective.
UV light cabinets
Another option is for cosmetology salons to use UV light cabinets. A disadvantage of this technology is that although UV germicidal light is effective at killing pathogens, it must strike all surfaces and this is difficult to achieve on a brush. The cabinets may also become reservoirs of pathogens if they are not regularly cleaned and disinfected.
Use of UV storage cabinets is superior to use of dry sterilant from a human health and environmental perspective, although there is the potential for UV light exposure if the cabinets are misused. This system has a higher cost than dry sterilant.
Preserved educational specimens for dissection
Secondary school and college students in anatomy classes dissect preserved specimens, including fetal pigs, frogs, cats, sharks and other species. Traditionally, educational specimens have been preserved with a formalin solution (a 37% solution of formaldehyde in water). Formaldehyde kills the bacteria that would otherwise decay the tissue. It also polymerizes the tissue, helping to maintain its texture, structure and color. This application does not account for a large percentage of formaldehyde use, but it poses particular public exposure concerns. Students, laboratory instructors and technicians are exposed to formaldehyde through their repeated contact with these specimens.
The Institute evaluated two categories of alternatives: use of specimens that are formaldehyde-free, and the technological alternative of video and virtual dissection.
Specimens in alternative solution
Using specimens of grass frogs as a typical application, an outside expert evaluated the technical performance of three alternative preservatives: Formalternate by Flinn Scientific, Wardsafe by Ward Scientific, and Streck Tissue Fixative (S.T.F.) Preservative by Nebraska Scientific. Formalternate is a combination of propylene glycol, ethylene glycol phenyl ether and phenol. Wardsafe is primarily glutaraldehyde. S.T.F. is a mixture of diazolidinyl urea, 2-bromo-2-nitropropane-1, 3-diol (Bronopol), zinc sulfate, and sodium citrate. Different species may be preserved in different solutions by the same company. All these alternative products are readily available from well-established companies.
- Health. All three alternatives are superior to formaldehyde-containing specimens from the perspective of carcinogenicity, sensitizing potential, and capacity to cause irritation. Some ingredients of the alternatives can cause skin, eye and respiratory irritation, and some can act as sensitizers, but they are less hazardous than formaldehyde on all these measures. Evaluating the health effects of Formalternate and S.T.F. is complicated by the fact that they are chemical mixtures. Glutaraldehyde, used in Wardsafe, has high acute toxicity, but is present at low concentrations in the specimen.
- Environment. Some of the chemicals used in the alternative fixatives are more toxic to fish and other species than is formaldehyde. In general, the low volatility and small amounts of preservative in the alternative specimens suggests that exposure for humans and the environment are likely to be very low. Life cycle considerations for the alternatives include the use and disposal of some ingredients, such as phenol and zinc sulfate, which are potential environmental pollutants.
- Technical criteria. All of alternatives match or exceed the important technical and performance criteria for educational specimens: color, texture, and stiffness of the specimen tissue. The color of the alternative specimens was as good as or better than the formalin-preserved specimen. The specimens varied in texture but all had acceptable characteristics.
- Cost. The prices of alternative specimens are similar to each other and generally less expensive than the formalin-fixed specimen.
Process change: Video dissection
Another alternative is to use video/virtual dissection instead of physical dissection of a preserved specimen.
- Health and Environment. Video/virtual dissection does not pose any of the health or environmental hazards for students or instructors associated with dissection of preserved specimens.
- Technical criteria. Video/virtual dissection offers different pedagogic opportunities from those afforded by physical dissection. Some instructors believe that video dissection is not an adequate substitute for dissection of preserved specimens, although it may be a useful supplement. However, the educational utility of video and/or virtual dissection may vary with the class or instructor. A complete assessment of the educational benefits of each option was beyond the scope of this study.
- Cost. The cost of video/virtual dissection programs is variable. Low- or no-cost materials are available, as are more expensive programs. In contrast to preserved specimens, these represent a one-time cost.
Hardwood plywood and structural use building panels
Adhesives used to make plywood, particleboard and other manufactured wood products account for the majority of formaldehyde consumed world wide each year. The components of wood panels vary depending on their intended use. Plywood and other products that are “exterior-grade” or need to withstand wet conditions are usually made with phenol-formaldehyde resin. Particleboard and medium-density fiberboard, often used for making furniture and cabinetry, are made with less expensive urea-formaldehyde resins, which have higher levels of formaldehyde emissions. Melamine-formaldehyde resins and polyacetal resins are also used in wood products and laminates and in molded plastic parts.
The Institute examined three alternatives that are currently available: Columbia Forest Products soy-based resin hardwood plywood panels, Homasote’s recycled paper panel boards, and Viroc’s wood fiber Portland cement panels. The Institute also assessed one emerging alternative that is not yet on the market, JER EnviroTech’s plastic-wood fiber panel.
The Columbia Forest Products soy-based resin hardwood plywood panel (Purebond) is a hardwood veneer core plywood panel. It can be used to make cabinets, built-in furniture, paneling, shelving, doors and other uses requiring a high end wood product.
- Human health. Purebond is superior to formaldehyde-resin plywood from the perspective of carcinogenicity and irritation/sensitizing properties. It eliminates potential formaldehyde exposures for users. However, its production involves use of epichlorohydrin as an intermediate. Epichlorohydrin is classified as a probable human carcinogen and poses other hazards to human health and the environment. This chemical could be a hazard to workers and the environment during production.
- Environment. The formaldehyde-based resin in conventional plywood has minor ecotoxicity. Purebond is similar to formaldehyde-resin plywood for this parameter.
- Technical Criteria. Technical characteristics of interest for this application include appearance/construction, strength of the glue bond when moist, fire resistance, warp resistance, and product availability. Purebond is similar to formaldehyde-containing plywood for the parameters of appearance/construction, fire resistance, and product availability. It has a glue bond superior to that of urea-formaldehyde plywood under conditions of moisture. Its warp resistance has not been assessed fully.
- Cost. Purebond is currently available at a similar cost to formaldehyde-resin plywood.
Structural use panels
The Institute assessed two alternatives that could be used in place of softwood plywood for structural use panels: Homasote’s recycled paper panel boards, and Viroc’s wood fiber Portland cement panels. Homasote’s recycled paper panels and Viroc’s wood fiber Portland cement panels may be used in place of softwood plywood and oriented strand board (OSB) in exterior sheathing, roof decking and floor decking. Viroc is used extensively in Europe.
- Health. Viroc and Homasote do not present a hazard to building occupants, but there are some occupational exposure concerns, such as exposure to wood and cement dust during cutting. Both products are superior to formaldehyde-resin plywood from the perspective of carcinogenicity of the binder. The Homasote panels are superior from the perspective of irritant in binder, while the Viroc panels are similar to formaldehyde-resin plywood on this metric.
- Environment. Both products are superior to formaldehyde-resin plywood from the perspective of ecotoxicity and natural resource conservation. The Viroc product is inferior from an energy intensity life cycle perspective.
- Technical criteria. Technical and performance criteria of interest for these uses include strength, weight, response to moisture, storage, handling, fastening, finishing, fire resistance, thermal resistance, and mold, rot and insect resistance. Both alternatives present some advantages and some disadvantages on these metrics. For example, Homasote is superior to formaldehyde-resin panels on several measures including resistance to insects, rot, and mold, and is inferior on certain other measures, such as impact resistance and tensile strength. Viroc is superior on measures including resistance to insects, rot, and mold, fire resistance, and impact resistance, and inferior on parameters such as tensile strength. Both Viroc and Homosote panels must be thicker and heavier than formaldehyde-resin panels to withstand an equivalent load over the same span.
- For a full report on this and other chemicals see the TURI Five Chemical Alternatives Assessment Study
- Chemical Economics Handbook, SRI Consulting (SRIC)
- Massachusetts Department of Environmental Protection, Toxics Use Reduction
- Toxics Use Reduction Institute homepage