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Chemical Identifying Information for Acetaldehyde
CAS NUMBER: 75-07-0
CHEMICAL FORMULA: C2H4O
SYNONYMS:
Acetic aldehyde
Ethanal
Ethyl aldehyde
NIOSH Registry Number: AB1925000
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MOLECULAR WEIGHT: 44.06
WLN: VH3
PHYSICAL DESCRIPTION: Colorless, fuming liquid
SPECIFIC GRAVITY: 0.778 @ 20/4 C [025]
DENSITY: Not available
MELTING POINT: -123.5 C [043],[058],[062]
BOILING POINT: 21 C [269],[275],[451]
SOLUBILITY:
Water: 0.1-1.0 mg/mL @ 19 C [700];
DMSO: >=100 mg/mL @ 18 C [700];
95% Ethanol: >=100 mg/mL @ 18 C [700];
Acetone: >=100 mg/mL @ 18 C [700];
Toluene: Miscible [062].
Gasoline: Miscible [062];
Solvent naptha: Miscible [062];
Xylene: Miscible [062];
Turpentine: Miscible [062];
Ether: Miscible [043],[062];
Benzene: Miscible [062];
Most organic solvents: Miscible [025];
Alcohol: Miscible [043].
OTHER PHYSICAL DATA:
Pungent, fruity odor [058],[062].
Odor threshold: 0.21 ppm [371].
Refractive index: 1.3316 @ 20 C [062],[269],[275].
Specific gravity: 0.7827 @ 20/20 C [043]; 0.7834 @ 18/4 C [047].
Specific gravity: 0.788 @ 16/4 C [031]; 0.8053 @ 0/4 C [205].
Vapor pressure: 740 mm Hg @ 20 C [058],[062]; 200 mm Hg @ 10 C [058].
HAP WEIGHTING FACTOR: 1 [713]
VOLATILITY: Vapor pressure: 400 mm Hg @ 4.9 C: 760 mm Hg @ 20.2 C [038]
Vapor density: 1.52 [043],[058]
FIRE HAZARD: Acetaldehyde has a flash point of -40 C (-40 F) [058],[062],[269],[275] and it is flammable. Fires involving this material may be controlled with a dry chemical, carbon dioxide or Halon extinguisher.
The autoignition temperature for acetaldehyde is 175 C (347 F) [043],[058],[451].
LEL: 4% [043],[058],[062],[451] UEL: 57% [043],[058],[062]
REACTIVITY: Acetaldehyde can react vigorously with acid anhydrides, alcohols, ketones, phenols, ammonia, hydrogen cyanide, hydrogen sulfide, halogens and amines [043],[058],[269],[451]. It can also react vigorously with phosphorous, isocyanates, strong alkalis and strong acids [043],[269]. It is incompatible with oxidizing and reducing agents [269]. Polymerization may occur with acetic acid. Autoignition of vapor on corroded metals may also occur on contact with acetaldehyde [036]. Exothermic polymerization can occur with trace metals [036],[043]. Acetaldehyde reacts with oxygen [043],[058],[066]. It also reacts with nitric acid, peroxides, caustic soda and soda ash [058]. It is reported that reactions with cobalt chloride, mercury (II) chlorate or mercury (II) perchlorate form sensitive and explosive products [043].
STABILITY: Acetaldehyde is dangerous when exposed to heat or flame [043],[058]. It is sensitive to air and may undergo autopolymerization [269]. It is sensitive to moisture [058]. Upon prolonged storage, it may form unstable peroxides [269]. Solutions of acetaldehyde in water, DMSO, 95% ethanol or acetone should be stable for 24 hours under normal laboratory conditions [700].
USES: Acetaldehyde is used in the manufacture of pentaerythritol, peracetic acid, pyridines, paraldehyde, acetic acid, acetic anhydride, 2-ethylhexanol, aldol, chloral, 1,3-butylene glycol, trimethylolpropane, butanol, perfumes, aniline dyes, plastics and synthetic rubber. It is used in silvering mirrors and in hardening gelatin fibers. It is also used as a chemical intermediate and synthetic flavoring substance and adjuvant.
ACUTE/CHRONIC HAZARDS: Acetaldehyde may be an irritant of the skin, eyes, mucous membranes and respiratory tract [269],[451]. It may also be an irritant to the throat [058]. It may be narcotic [031],[062]. When heated to decomposition it emits acrid smoke and toxic fumes of carbon monoxide and carbon dioxide [043],[058],[269].
SYMPTOMS: Symptoms of exposure may include nausea, vomiting, headache, dermatitis and pulmonary edema. These effects may be delayed. It may also cause skin, eye, mucous membrane and upper respiratory irritation [269]. It may have a general narcotic action and large doses may cause death by respiratory paralysis [031]. It may also cause drowsiness, delirium, hallucinations and loss of intelligence [036]. Exposure may also cause slow mental response, severe damage to the mouth, throat and stomach; accumulation of fluid in the lungs, chronic respiratory disease, kidney and liver damage, throat irritation, dizziness, reddening and swelling of the skin and sensitization [058]. It may cause photophobia [099]. It may cause unconsciousness and liquid splashed in the eyes may cause a burning sensation, lacrimation and blurred vision [102]. It may also cause transient conjunctivitis [395].
Numbers in brackets [ ] are reference numbers in the source of this information.
Source: Instant EPA's Air Toxics, Copyright 1994 by Instant Reference Sources, Inc. and Digital Liaisons, Austin, Texas
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The data below is scanned from Instant Tox-Base. This database contains data on over 1800 chemicals in a highly condensed tabular format. Abbreviations and Definitions used throughout can be viewed here but they are all hyperlinked to the text within Instant Tox-Base for convenience.
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EPA's IRIS is the world's most comprehensive toxicology database. Chemical entries often range from 20 to 50 pages of information. The information below represents a small selection of the data involving carcinogenicity in Section II of IRIS. Many of the technical terms are hyperlinked with explanations in Instant EPA's IRIS from which the following exerpts were taken but space limitations preclude that convenience here.
II.A. EVIDENCE FOR CLASSIFICATION AS TO HUMAN CARCINOGENICITY
II.A.1. WEIGHT-OF-EVIDENCE CLASSIFICATION
Classification -- B2; probable human carcinogen
Basis -- Based on increased incidence of nasal tumors in male and female rats and laryngeal tumors in male and female hamsters after inhalation exposure.
II.A.2. HUMAN CARCINOGENICITY DATA
Inadequate. The only epidemiological study involving acetaldehyde exposure showed an increased crude incidence rate of total cancer in acetaldehyde production workers as compared with the general population (Bittersohl, 1974). Because the incidence rate was not age adjusted, and because this study has several other major methodological limitations (including concurrent exposure to other chemicals and cigarette exposure, short duration, small number of subjects, and lack of information on subject selection, age and sex distribution) it is considered inadequate to evaluate the carcinogenicity of acetaldehyde.
II.A.3. ANIMAL CARCINOGENICITY DATA
Sufficient. Feron (1979) exposed groups of 35 male Syrian Golden hamsters to 0 or 1500 ppm acetaldehyde by inhalation 7 hours/day, 5 days/week, for 52 weeks. These animals were also exposed weekly by intratracheal instillation to increasing doses of benzo(a)pyrene (BaP) in 0.2 mL of 0.9% NaCl, or to NaCl alone. Animals were killed and autopsied after exposure and 26 weeks of recovery in air. No neoplastic effects due to acetaldehyde alone were found. The highest BaP dose (1 mg/week for 52 weeks) combined with acetaldehyde exposure produced twice the incidence of squamous cell carcinomas compared with the same dose of BaP alone. In the second part of this study, no respiratory tract tumors were found in groups of 25 male hamsters which were intratracheally instilled once a week with 0.2 mL of 2% or 4% acetaldehyde in 0.9% NaCl for 52 weeks.
Feron et al. (1982) studied male and female hamsters exposed by inhalation to acetaldehyde alone or in combination with intratracheally administered BaP or diethylnitrosamine. The animals were exposed for 7 hours/day, 5 days/week, for 52 weeks to a time weighted average concentration of 2028 ppm. They were killed and autopsied after a 29-week recovery period; that is, at week 81. A slight increase in nasal tumors and a significantly increased incidence of laryngeal tumors was observed in both male and female hamsters exposed to acetaldehyde alone. This study supported the observation of Feron (1979) that acetaldehyde treatment enhanced tumorigenicity (production of tracheobronchial carcinomas) of BaP.
The carcinogenicity of acetaldehyde was studied in 420 male and 420 female albino SPF Wistar rats (Woutersen and Appelman, 1984; Woutersen et al., 1985). After an acclimatization period of 3 weeks, these animals were randomly assigned to four groups of 105 males and 105 females each. The animals were then exposed by inhalation to atmospheres containing 0, 750, 1500, or 3000 ppm acetaldehyde for 6 hours/day, 5 days/week, for 27 months. The concentration in the highest dose group was gradually reduced from 3000 to 1000 ppm because of severe growth retardation, occasional loss of body weight and early mortality in this group. Interim sacrifices were carried out at 13, 26, and 52 weeks. One tumor was observed in the 52 week sacrifice group and none at earlier times. Exposure to acetaldehyde increased the incidence of tumors in an exposure-related manner in both male and female rats. In addition, there were exposure-related increases in the incidences of multiple respiratory tract tumors. Adenocarcinomas were increased significantly in both male and female rats at all exposure levels, whereas squamous cell carcinomas were increased significantly in male rats at middle and high doses and in female rats only at the high dose. The squamous cell carcinoma incidences showed a clear dose-response relationship. The incidence of adenocarcinoma was highest in the mid-exposure group (1500 ppm) in both male and female rats, but this was probably due to the high mortality and competing squamous cell carcinomas at the highest exposure level. In the low-exposure group, the adenocarcinoma incidence was higher in males than in females.
Source: Instant EPA's IRIS, Copyright 1996 by Instant Reference Sources, Inc. and Digital Liaisons, Austin, Texas
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The table below was scanned from Instant Gloves + CPC Database. It contains information on the breakthrough times and permeation rates for Acetaldehyde tested against many manufacturer's models of CPC. If you are not familiar with the chemical permeation test procedures and the interpretation of breakthrough time and permeation rate data then you will find the Permeation Index Number to be useful in helping you make selections.
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Method TO-5 is used to analyze individual aldehydes and ketones in ambient air.
2.0 SUMMARY OF METHOD
Air is drawn through a midget impinger containing dinitrophenylhydrazine (DNPH) reagent and isooctane where the target compounds are derivatized. The organic fraction is evaporated to dryness and dissolved in methanol. The derivatives are determined using reverse phase high performance liquid chromatography HPLC with an ultra-violet detector.
EPA Method 0030 is used to calculate destruction and removal efficiency (DRE) of volatile principal organic hazardous constituents (POHCs) from stack gas effluents of hazardous waste incinerators, and enable a determination that DRE values are equal to or greater than 99.99 percent. For the purpose of definition, volatile POHCs are those POHCs with boiling points less than 100°C. If the boiling point of a POHC of interest is less than 30°C, the POHC may break through the sorbent under the conditions of the sample collection procedure.
2.0 SUMMARY OF METHOD
A 20-L sample of effluent gas is withdrawn from an emission source at a flow rate of 1 L/min, using a glass-lined probe and a volatile organic sampling train (VOST). The gas stream is cooled to 20°C by passage through a water-cooled condenser and volatile POHCs are collected on a pair of sorbent resin traps. Liquid condensate is collected in an impinger placed between the two resin traps. The first resin trap (front trap) contains approximately 1.6 g Tenax ® and the second trap (back trap) contains approximately 1 g each of Tenax ® and petroleum-based charcoal (SKC lot 104 or equivalent), 3:1 by volume.
An alternative set of conditions for sample collection has been used. This method involves collecting a sample volume of 20 L or less at a reduced flow rate. (Operation of the VOST under these conditions has been referred to as SLO-VOST.) This method has been used to collect 5 L of sample (250 mL/min for 20 min) or 20 L of sample (500 mL/min for 40 min) on each pair of sorbent cartridges. Smaller sample volumes collected at lower flow rates should be considered when the boiling points of the POHCs of interest are below 35°C.
Source: Instant EPA's Air Toxics, Copyright 1994 by Instant Reference Sources, Inc. and Digital Liaisons, Austin, Texas
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