A SOLUTION TO THE IRRITATING PROBLEMS OF FORMALDEHYDE

Welcome... The case against formaldehyde grows. For years, its health hazards have been widely recognized. Now, severe environmental problems and technical considerations argue even more strongly against its use. In this issue of The Innovator, we will look briefly at these points and suggest a way around them. There are fixatives that avoid all of these difficulties. ANATECH LTD. pioneered the leading class of formalin substitutes, and remains the technical leader in this field. Many of you have tried other formalin substitutes, only to be disappointed in their performances and cost. We invite you to consider Prefer, the formalin-free fixative that works. Review its advantages and see if there is a place for it in your lab.

Health Effects

Breast (human),estrogen receptor without antigen retrieval. 20x

OSHA's Formaldehyde Standard did much to create awareness of formaldehyde's health effects, including its carcinogenicity.

The regulation was responsible for dramatically improving workplace conditions, but we continue to learn of tragic cases of histotechnologists and pathologists who have become allergic to this chemical.

Sensitization is one of the more unfortunate consequences of working with formaldehyde. Repeated exposure through skin contact or inhalation produces an allergic response varying from dermatitis to respiratory problems. Allergic contact dermatitis generally becomes more severe with repeated exposure.

Environmental concerns

Disposal of formalin has been a problem in many areas of the United States and Canada for many years. Few municipalities will grant permission to dispose of formalin down the drain, although many laboratories do so without seeking authorization. Prices of $300-600 per barrel (55 gallons) are common for having a licensed waste hauler dispose of formalin; some of you pay substantially more than that. Destruction of waste formalin in the lab is feasible for many labs, but equally costly. Recycling is the best waste management strategy short of eliminating formalin altogether, but even it does not entirely eliminate environmental contamination.

Over the last few years, we have worked closely with wastewater and environmental agencies to deal with ways to keep formaldehyde and other hazardous chemicals out of the sanitary sewer system (see Ornelas, et al., 1998a and 1998b for one such effort). We are now aware of a major initiative in parts of New England to effect a dramatic change in the way laboratories discharge waste down the drain. Current limits for formaldehyde in wastewater coming from laboratory drains is 1 ppm in that area. Even if all formalin is collected and not discarded down the drain, it is still next to impossible to stay under this limit just from the formaldehyde washed off of specimens during grossing. To put 1 ppm in perspective, it equates to adding about 50 ml of 10% NBF to every 500 gallons of water. If only 1 ml of formalin is washed off each specimen, it would take roughly 50 specimens to be in violation.

The EPA as well as regional and municipal wastewater authorities are serious about this. If you currently are not in an area with aggressive programs to deal with the problem of environmental contamination, you probably soon will be. We do not tell you these things to scare you (remember, we are a major supplier of formaldehyde-based fixatives). However, we do support the efforts of these authorities wholeheartedly, and have made preparations in our business to meet these welcome challenges. We urge you to do likewise.

Technical difficulties

If health and environmental concerns are not sufficient to have formaldehyde removed from your laboratory, consider formalin on its technical merits. As fixation time has shrunk from a day or more to a mere few hours or less, artifacts have been increasingly prevalent. Pale blue hazy nuclei, lost chromatin patterns and bizarre staining patterns are now seen commonly in many labs. For descriptions and explanations for these artifacts, see The Artifact of Managed Health Care in The Innovator 2(1), 1998. Formalin is simply too slow for today's hurried needs, and yet it is too fast for the sophisticated immunohistochemical tests that are being sought.

Immunoreactivity is difficult to preserve intact, and formalin is perhaps the worst of all fixatives for this. It readily masks antigenic sites, even with brief fixation times. Antibodies raised against formalin-fixed antigens are available and certainly help, but antigen recovery has become a standard part of immunohistochemical staining. Unfortunately, any attempt to retrieve antigenicity is filled with pitfalls and difficulties. The fact that there are literally hundreds of papers detailing procedures for this (Shi, et al., 1997) is stark testimony to the likelihood of achieving desired results on any particular antigen in your laboratory.

Why is antigen retrieval so capricious? There is no standardization for fixation in our field, and none is likely to be accepted. In many labs, specimens are fixed for however long it takes to get them there and grossed. This can be anywhere from an hour or less to a day or more. The latter will need antigen retrieval for many antigens, while the former specimens will be damaged by the same procedures (Rimsza et al., 1999).

Wouldn't it make more sense to avoid the problem of antigen retrieval by using a fixative that preserves immunoreactivity? It is fine to have a body of protocols to salvage ruined specimens, but we should not intentionally ruin them just because we can usually recover some semblance of immunoreactivity in most antigens, hopefully without having created false positive staining. This simply does not make sense!

The alternative

Eliminating formalin is the obvious strategy, but will the replacement produce satisfactory results from a histological perspective? That was our challenge for seven years while we tried to develop a formalin substitute. For us, the new product could not simply be as good as formalin, it had to be technically superior. With fixation times dwindling dramatically in clinical histology, and immunohistochemistry putting new demands upon us, we created a fixative that we hoped would fill the bill. Now, after 6 years of selling the product at a level far beyond our expectations, we are confident that there is no better alternative today. If you are not aware of it, let us introduce you to Prefer. We are happy to tell you about its active ingredients and how they work. The accompanying photographs are from specimens prepared by us and by various customers, under a wide range of field conditions. In other words, they are "real-world" evidence that Prefer truly is the formalin-free fixative that works.

Prefer is not a sensitizer and has no carcinogenic properties. Glyoxal has almost no vapor pressure; therefore, it does not evaporate and poses no inhalation hazard. The modest odor of Prefer is from the ethanol and buffer, and is harmless.

Safe but not non-hazardous

We want you to know that this fixative is not like some other formalin substitutes. Prefer has some mild hazardous properties. It has to be hazardous to some extent if it is going to be effective as a fixative. The active ingredients are skin and eye irritants; this solution will fix living fingers and eyes just as it fixes surgical specimens. If it didn't pose an irritation risk to you, it would not be worth much as a fixative (which is the major problem with some of the formalin substitutes currently on the market). A fixative cannot be non-hazardous and still work as a fixative; it cannot work selectively on specimens and not work on your skin and cornea.

You have come to expect a level of technical support from ANATECH LTD. that is unparalleled in the industry. Before bringing a new product to market, we not only make certain that it performs satisfactorily, we also find out how and why it works. When you have questions, problems or unanticipated ways of using it, we can help.

Disposal

In most municipalities, Prefer can be discarded down the drain. It is biodegradable in timely fashion and has a low level of aquatic toxicity. It will not inhibit bacteria in effluent if properly introduced into a biological treatment facility. Detailed information to this effect appears in our Material Safety Data Sheet and package insert. Please note that we recommend drain disposal because of Prefer's properties and actual test data. Some other formalin substitutes suggest drain disposal merely because their ingredients do not appear on EPA lists of hazardous chemicals. Most chemicals are not listed simply because the EPA has not had the time to study them. Your wastewater treatment plant, not the EPA, is the ultimate authority; its personnel must be assured that the chemicals entering their system will not harm the biological processes upon which they depend for waste purification. We can provide that assurance.

Formaldehyde is one of the least expensive commodity chemicals, and any replacement is going to be more costly. The ingredients in Prefer are no exception; but our products are not outrageously priced. When you consider the cost of compliance with various OSHA standards (medical surveillance, monitoring, training, labeling and spill response), Prefer is a very attractive alternative to formalin. If your lab is truly in compliance with all health, safety and disposal regulations regarding formaldehyde, your hidden expenses will far exceed the modest additional cost of Prefer.