Formaldehyde health effects

Sensitizer A sensitizer is defined by OSHA as "a chemical that causes a substantial proportion of exposed people or animals to develop an allergic reaction in normal tissue after repeated exposure to the chemical." The condition of being sensitized to a chemical is also called chemical hypersensitivity. Certain chemicals have no immediate health effect. But if you are exposed to them several times, they can make you allergic or sensitive to other chemicals. A classic example is formaldehyde (HCHO). Typical reactions to sensitizers can include skin disorders such as eczema. When working with sensitizers, always use proper protective equipment such as gloves, respirators, etc. Once you are sensitized to a particular chemical, even minute amounts will cause symptoms. Sensitization is usually a lifelong effect. 

Aldehydes may also be thought of as photochemical oxidants. The definition here becomes a bit hazy, because aldehydes in themselves are photooxidative reactants, as well as secondary pollutants that have adverse health effects. Referring to Figure 4-4, we note that aldehyde concentration throughout the day in Rome, Italy, seems to decay at roughly the same rate as the nitric oxide concentration. It would be expected to track the reactive fraction of the hydrocarbons, and this is also borne out approximately by the Rome data. A maximal formaldehyde concen-... 

Toxicity and health effects Exposure to high concentrations of formaldehyde is known to cause irritation to the eyes, nose, and throat fatigue headache ... 

Environmental scientists have generally defined exposure and health effects on a pollutant-by-pollutant basis. In indoor environments these include multiple air pollutants (i.e., 20-50 different VOCs, including formaldehyde and other aldehydes), microbial products (including spores, cell fragments, viable organisms, and secretion products), and reactive agents such as ozone, fibers, and others. The American Thoracic Society defined six important categories listed in Table 4. 

We have no reliable test to determine how much formaldehyde you have been exposed to or whether you will experience any harmful health effects. 

Estimates of exposure levels posing minimal risk to humans (Minimal Risk Levels or MRLs) have been made for formaldehyde. An MRL is defined as an estimate of daily human exposure to a substance that is likely to be without an appreciable risk of adverse effects (noncarcinogenic) over a specified duration of exposure. MRLs are derived when reliable and sufficient data exist to identify the target organ(s) of effect or the most sensitive health effect)s) for a specific duration within a given route of exposure. MRLs are based on noncancerous health effects only and do not consider carcinogenic effects. MRLs can be derived for acute, intermediate, and chronic duration exposures for inhalation and oral routes. Appropriate methodology does not exist to develop MRLs for dermal exposure. 

In a study of volunteers exposed to 1 ppm for 90 minutes, seven subjects reported eye irritation and three reported nasal congestion among nine subjects who had previously complained of health effects from exposure to urea-formaldehyde insulation in their homes (Day et al. 1984). A similar response to 1 ppm formaldehyde was noted among the other nine subjects in this study who had no previous complaints eight reported eye irritation and four reported nasal congestion from the 90-minute exposure. 

Garry et al. (1980) investigated the health effects associated with formaldehyde exposure in Minnesota residents. A total of 275 cases of possible formaldehyde exposure were investigated between February and June 1979. Medical histories of the patient and all family members were recorded, and 30-minute air samples were collected from the living room and bedroom of each residence. Environmental information (age, type of home, type of insulation, type of heat) was also collected. Formaldehyde levels ranged from 0.1 to 3 ppm. The rate of miscarriages in exposed women in this study (11.6%) did not differ from the rate of miscarriages seen in other studies of non-exposed women. There is no information on the duration of exposure therefore, chronic-duration exposure is assumed. 

No studies were located regarding cardiovascular, gastrointestinal, hematological, musculoskeletal, hepatic, or renal health effects in humans or animals after dermal exposure to formaldehyde. 

Section 104(i)(5) of CERCLA, as amended, directs the Administrator of ATSDR (in consultation with the Administrator of EPA and agencies and programs of the Public Health Service) to assess whether adequate information on the health efiects of formaldehyde is available. Where adequate information is not available, ATSDR, in conjunction with the National Toxicology Program (NTP), is required to assure the initiation of a program of research designed to determine the health effects (and techniques for developing methods to determine such health effects) of formaldehyde. 

The existing data on health effects of inhalation, oral, and dermal exposure of humans and animals to formaldehyde are summarized in Figure 2-5. The purpose of this figure is to illustrate the existing... 

Figure 2-5. Existing Information on Health Effects of Formaldehyde...

Studies of health effects in humans after intermediate-duration inhalation exposure were not located. Studies of humans with predominately chronic inhalation exposure to formaldehyde under occupational... 

Chronic-Duration Exposure and Cancer. As with the shorter durations of exposure, the critical targets of chronic inhalation, oral, or dermal exposure to formaldehyde are expected to be portal-of-entry tissues. For the inhalation route, the data are abundant, of good quality, and include both human and animal data. Less health effects data are available for chronic oral and chronic dermal exposure, but the weight of the available data is consistent with this expectation. 

Reliable monitoring data for the levels of formaldehyde in contaminated media at hazardous waste sites are needed so that the information obtained on levels of formaldehyde in the enviromnent can be used to assess the potential risk of adverse health effects in populations living in the vicinity of hazardous waste sites. 

Effect As discussed in the previous section, DNA-protein cross links and anti-formaldehyde-human serum albumin IgG antibodies are potential biomarkers of effect and exposure. Whereas detection of these biomarkers can represent biological responses to repeated exposure to formaldehyde (the first is not specific to formaldehyde, but the second is), it is uncertain to what degree their detection indicates that adverse health effects will occur. Further research on relationships between formaldehyde-induced upper respiratory tract tissue damage and/or dysfunction and (1) DNA-protein cross links in either white blood cells or nasal biopsy tissue or (2) levels of formaldehyde-specific IgG antibodies may help in determining if improved detection methods are needed. 

Liu KS, Huang FY, Hayward SB, et al. 1991. Survey of formaldehyde concentrations and health effects in mobile homes [Abstract]. Arch Environ Health 46 181-182. 

NAS/NRC. 1980. Formaldehyde An assessment of its health effects. Committee on Toxicology, National Research Council, National Academy of Sciences for the Consumer Product Safety Commission, Washington, DC. AD A 087 854, NAS/ACT/P-881A. 

Quackenboss JJ, Lebowitz MD, Michaud JP, et al. 1989. Formaldehyde exposure and acute health effects study. Environ Int 15 169-176. 

Committee on Toxicology "Formaldehyde—An Assessment of Its Health Effects," prepared for Consumer Product Safety Commission by National Academy Sciences, 1980. 

During the past decade, urea formaldehyde and phenol formaldehyde resin binders have contributed greatly to the progress of wood industries. Formaldehyde is widely used as a major component in the production of building materials, such as particleboard and plywood, and in urea formaldehyde foam insulation. However, the emissions of formaldehyde from these products create considerable concerns not only in the working environments but also in residences, mobile homes, and office buildings. These concerns have also been stimulated by reports on the health effects and carcinogenicity associated with formaldehyde exposure. 

The acute toxic effects of formaldehyde are reasonably well known (2). The health effects of formaldehyde have been documented by by NTOSH (12) and OSHA and by a review by the National Research Council for EPA. The setting of standards for formaldehyde has followed the usual standard setting procedure for all toxic chemicals (1. ... 

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