Environmental Engineering Reference
In-Depth Information
Individual aldehydes differ in their molecular structure, solubility, chem-
ical reactivity, and toxicity. Only a relative few have industrial and commer-
cial applications which may result in significant indoor exposures, are by-
products of other processes, or have biological activities that have the poten-
tial for posing major public health concerns. Those which, at present, are
known to cause either significant indoor air contamination and/or adverse
health effects include formaldehyde (HCHO), acetaldehyde, acrolein, and
glutaraldehyde. Many aldehydes are potent sensory (mucous membrane)
irritants; some are skin sensitizers; and there is limited evidence that several
aldehydes may be human carcinogens.
A. Sensory irritation
Because of their solubility in aqueous media and their high chemical activity,
aldehydes as a group are potent mucous membrane irritants (affecting eyes
and mucous membranes of the upper respiratory tract). This irritation is
associated with maxillary and ophthalmic divisions of trigeminal nerves in
nasal and other mucosa which respond to chemical/physical stimuli. These
serve as respiratory defense mechanisms through the perception of pain or
irritation and reduced contaminant inhalation.
Measured decreases in respiratory rates in rats and mice on exposure to
irritant chemicals have been used to evaluate the irritation potential of alde-
hydes and other substances using a standard mouse bioassay. Doses required
to cause a reduction of breathing rates by 50% (RD
50
values
range by more than three orders of magnitude. Formaldehyde and the unsat-
50
Table 4.2
RD
Values for Swiss-Webster Mice Exposed
50
to Aldehydes
Chemical
RD
value (ppmv)
50
Formaldehyde
3.2
Acetaldehyde
2845
Propionaldehyde
2052
Acrolein
1.03
Butryaldehyde
1015
Isobutryaldehyde
4167
Crotonaldehyde
3.53
Valeraldehyde
1121
Isovaleraldehyde
1008
Caproaldehyde
1029
2-Ethybutryaldehyde
843
2-Furaldehyde
287
Cyclohexane carboxaldehyde
186
3-Cyclohexane-1-carboxaldehyde
95
Benzaldehyde
333
Source:
From Steinhagen, W.H. and Barrow, C.,
Toxicol. Appl.
Pharmacol
., 72, 495, 1982. With permission.
