Human odor thresholds

Because toluene is fairly volatile, exposure for humans would occur principally by inhalation. It has a human odor threshold of 0.1mgm ( 26ppb). Dermal exposure may also be significant, especially in an industrial setting, where skin may be exposed... 

FLEC measurements of a complaint case of malodorous linoleum showed that wetting of the material increased the emission of, e.g., odorous fatty acids. (Wolkoff et al., 1995). The impact of humidity has also been investigated for other building products (Wolkoff, 1996b). In this article, the impact of temperature, nitrogen instead of air and air velocity in the FLEC have also been investigated for VOCs with low human odor thresholds. 

Repeated exposures of animals to high (near-lethal) concentrations of vapors result in inflammation of the respiratory tract, as weU as degenerative changes in the Hver, kidneys, and heart muscle. These effects arise at concentrations far above those causing irritation. Such effects have not been reported in humans. The low odor threshold and irritating properties of acrylates cause humans to leave a contaminated area rather than tolerate the irritation. 

The most serious ha2ard of repeated exposure to chloroform inhalation is injury to the Hver and kidneys. Evidence indicates that in humans, repeated exposure to atmospheric concentrations well below the odor threshold may cause such injury. Industrial experience has shown that daily exposure to concentrations below 100 ppm may result in a variety of nervous system and alimentary tract symptoms, in the absence of demonstrable evidence of injury (39). Injury to the Hver is similar to but somewhat less severe than that caused by carbon tetrachloride. Kidney injury is usually associated with but less severe than Hver injury. 

Health Hazards Information - Recommended Personal Protective Equipment Dust mask goggles or face shield protective gloves Symptoms Following Exposure Inhalation of dust irritates nose and throat. Contact with eyes causes irritation General Treatment for Exposure INHALATION move to fresh air. EYES flush immediately with physiological saline or water get medical care if irritation persists. SKIN flush with water Toxicity by Inhalation (Thresholdlimit Value) Data not available Short-Term Exposure Limits Data not available Toxicity by Ingestion Grade 1 oral LDjq 11.7 g/kg (rat) Late Toxicity Chronic effects in humans are unknown Vapor (Gas) Irritant Characteristics Not pertinent liqidd or Solid Irritant Characteristics Data not available Odor Threshold Data not available. 

Health Hazards Information - Recommended Personal Protective Equipment Eye protection Symptoms Following Exposure Vapors from very hot material may irritate eyes and produce headache, drowsiness, and convulsions General Treatment for Exposure Remove fresh air. Wash affected skin areas with water. Flush eyes with water Toxicity by Inhalation (ThresholdLimit Value) 5 mg/m Short-Term Exposure limits Not pertinent Toxicity by Ingestion Grade 1 LDjq 5 to 15 g/kg Late Toxicity Birth defects in rats polyneuritis in humans Vapor (Gas) Irritant Characteristics Not pertinent liquid or Solid Irritant Characteristics No appreciable hazard. Practically harmless to the skin Odor Threshold Data not available. 

Reference The available human and animal data indicate that there is very little margin between seemingly inconsequential exposures and lethal exposures. The mechanism of arsine toxicity (hemolysis and subsequent renal failure) and the fact that toxicity has been demonstrated at or below the odor threshold justify the inappropriateness of AEGL-1 values for any exposure period. 

The human taste threshold for PCP in drinking water is about 30 pg/L (USEPA 1980), a level far below the upper safe limit of 1.01 mg/L and near the no-observable-effect level of 21 pg/L (Table 23.7). Odor detection is not as sensitive as taste the odor threshold for PCP ranges from about 857 pg/L at 30°C, to 1600 pg/L at 20 to 22°C, to 12,000 pg/L at 60°C (USEPA 1980). It is not clear whether the determined organoleptic threshold values made the water undesirable or unfit for consumption (USEPA 1980). If fish and wildlife species of concern have PCP organoleptic thresholds that are similar to those of humans, or lower, will they too avoid contaminated habitats or diets ... 

The odor threshold, 0.58 ppm to 5.0 ppm (Amoore and Hautala 1983 Ruth 1986) is low compared with irritant or toxic concentrations. No acute exposures were located resulting in mild effects in humans. Three monitoring studies, involving no symptoms to mild symptoms during chronic occupational exposures of adult males, are relevant to development of AEGL-1 values. The symptoms and blood concentrations of cyanide in the monitoring study of Chandra et al. (1980) indicate that the workers may have been exposed at higher atmospheric concentrations than those reported. 

White crystalline solid or orthorhombic bipyramidal needles from alcohol. Coal tar-like odor. The lowest odor threshold concentration in water that may result in rejection of contaminated water ranged from 0.02 to 0.22 ppm (Lillard and Powers, 1975). In Wisconsin, the taste and odor threshold concentration in water that is nontoxic to humans is 20 pg/L (ATSDR, 1995). 

Odor thresholds in humans appear to be more influenced by the environment than genetics. The detection thresholds for acetic acid, isobutyric acid, and cyclohexanone varied as much in monozygotic twins as in fraternal twins. Instead, smoking and diabetes were related to lower olfactory sensitivity, and body fatness and alcohol consumption to greater sensitivity to the latter two compounds (Hubert eta/., 1980). 

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