Pyridine

Direct observations: clinical cases, poisoning incidents and other

Administrative data

Endpoint:

direct observations: clinical cases, poisoning incidents and other

Type of information:

other: case reports

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: Anecdotal case reports are not able to be evaluated for reliability

Data source

Reference

Reference Type:

other: case reports

Title:

Pyridine, Human Toxicity Excerpts

Author:

Anonymous

Year:

2010

Bibliographic source:

Hazardous Substances Data Base, http://toxnet.nlm.nih.gov/cgi-bin/sis/search/f?./temp/~rQdXG1:1

Materials and methods

Study type:

other: case reports

Endpoint addressed:

not applicable

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Anecdotal case reports as published in the literature or as reported to government agencies.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Pyridine

EC Number:

203-809-9

EC Name:

Pyridine

Cas Number:

110-86-1

Molecular formula:

C5H5N

IUPAC Name:

pyridine

Method

Type of population:

occupational

Ethical approval:

not applicable

Reason of exposure:

unintentional, occupational

Exposure assessment:

not specified

Results and discussion

Clinical signs:

May cause CNS depression, irritation of skin and respiratory tract. Large doses may produce GI disturbances, kidney and liver damage.

Any other information on results incl. tables

Human Toxicity Excerpts:
... AFTER VAPOR INHALATION ... /SRP: CENTRAL NERVOUS SYSTEM DEPRESSION/. SMALL ORAL DOSES (2 TO 3 ML) ... PRODUCE MILD ANOREXIA, NAUSEA, FATIGUE, AND MENTAL DEPRESSION ... AFTER PROLONGED DAILY ADMIN HEPATORENAL DAMAGE ... INGESTION OF SEVERAL OUNCES HAS PRODUCED SEVERE VOMITING, DIARRHEA, HYPERPYREXIA, DELIRIUM, & DEATH ... INGESTION OF SEVERAL OUNCES ... PRODUCED ... DEATH IN 43 HOURS; AUTOPSY REVEALED PULMONARY EDEMA AND MEMBRANOUS TRACHEOBRONCHITIS ... .


May cause smarting of the skin and first-degree burns on short exposure; may cause secondary burns on long exposure.


Clinical symptoms and signs of intoxication include gastrointestinal disturbance with diarrhea, abdominal pain, nausea, weakness, headache, insomnia, and nervousness; at low concentrations, varying degrees of liver damage occur with centrilobular fatty degeneration, congestion, and cellular infiltration.Pyridinealso causes irritation upon contact with mucous membranes, skin, and eyes.


Unusual acute poisoning frompyridinewas described. A woman was decontaminating a spill for 15-20 min. Symptoms did not occur for 10 hr & intensified until the third day. Symptoms included speech disorders & "rather diffused cortical affliction" which receded after thiamine therapy. Upper respiratory symptoms were not present at all.


May cause CNS depression, irritation of skin and respiratory tract. Large doses may produce GI disturbances, kidney and liver damage.


Prolonged exposure topyridinemay result in liver, heart and kidney damage followed by coma and death.


Most of the effects observed in man have been caused by repeated or intermittent exposure to the vapor. Clinical symptoms & signs of intoxication include GI disturbance with diarrhea, abdominal pain & nausea, weakness, headache, insomnia & nervousness. Exposure less than those required to produce overt clinical signs may cause varying degrees of liver damage with central lobular fatty degeneration, congestion & cellular infiltration; repeated low-level exposures cause cirrhosis. The kidney is less sensitive topyridine- induced damage than is the liver. In general,pyridine& its derivatives cause local irritation on contact with the skin, mucous membranes & cornea.


... Usingpyridinein clinical applications for epilepsy, found that 1.85 to 2.46 ml orally caused mild anorexia, nausea, fatigue, & depression. The highest doses produced severe emesis, diarrhea, delerium hyperpyrexia, & one death with profound hepatic & renal damage at some 40 hr after ingestion. Pulmonary edema & tracheobronchitis (perhaps secondary to aspiration of vomitus) were also seen at autopsy. ... When ingested,pyridinecan depress the CNS. Large doses can potentially act as a cardiotoxic agent, whereas smaller doses were said to stimulate hematopoiesis, resulting in an increased production of blood platelets. The vapor is irritating to mucous surfaces, causing ocular & upper respiratory tract irritation. ... The most important effect ofpyridineinhalation was chronic poisoning, centering upon the liver, kidneys, & bone marrow; mild symptoms ofpyridineintoxication can result from exposure at 10 ppm. ... Chronic poisoning with mild symptoms of CNS injury in workers employed at a plant wherepyridinevapor concns ranged from 6-12 ppm. ... Despite relatively large amounts ofpyridineused in industry, reports of injuries due topyridineexposure are rare. Transient symptoms of overexposure include nausea, headache, insomnia, nervousness, & low back or abdominal discomfort with urinary frequency. These transient symptoms, without associated evidence of liver or kidney damage, have occurred in individuals exposed topyridineconcns averaging 125 ppm, 4 hr/day for 1-2 wk.


... Central nervous depression; also in man after vapor inhalation. Small oral dose (2-3 ml) in man produce mild anorexia, nausea, fatigue, & mental depression, & after prolonged daily admin hepatorenal damage. ... The ingestion of several ounces has produced severe vomiting, diarrhea, hyperpyrexia, delirium, & death in 43 hr; autopsy revealed pulmonary edema & membranous tracheobronchitis (due to aspiration).


...Congestion of the epiglottis, trachea, bronchi, lungs, esophagus, & stomach was reported in a case of accidental swallowing of half a cupful ofpyridinewhich resulted in death. This common finding of congestion would indicate thatpyridineis irritating to mucous membranes of the GI & respiratory systems.

Another case study reported the incident of a 29 yr old man who died within 2 days of ingesting approx a half cup (about 125 ml) ofpyridineduring a syphoning accident. Upon admission to a hospital he was treated by the admin of demulcents (not otherwise described), milk, & brandy, application of mustard & linseed poultices to his throat & chest, & a brandy enema which he was reported to have retained. It is not clear whether this medical intervention was of benefit to this man or possibly exacerbated an already serious situation.

Applicant's summary and conclusion

Conclusions:

Ingestion of pyridine may cause central nervous system depression, irritation of skin and respiratory tract. Large doses may produce GI disturbances, kidney and liver damage. Inhalation of pyridine may cause central nervous system depression.