Pyridine Safety Data Sheets

Flammable liquids, Category 2

Acute toxicity - Category 4, Oral

Acute toxicity - Category 4, Dermal

Acute toxicity - Category 4, Inhalation

If inhaled

Following skin contact

Following eye contact

Following ingestion

Vapor irritates eyes and nose. Liquid irritates skin and is absorbed through the skin. Overexposure causes nausea, headache, nervous symptoms, increased urinary frequency. (USCG, 1999)

Behavior in Fire: Vapor is heavier than air and may travel considerable distance to source of ignition and flash back. (USCG, 1999)

Use water in large amounts, powder, alcohol-resistant foam, carbon dioxide. In case of fire: keep drums, etc., cool by spraying with water.

Personal protection: self-contained breathing apparatus. Remove all ignition sources. Do NOT wash away into sewer. Collect leaking and spilled liquid in sealable containers as far as possible. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations.

Personal protection: self-contained breathing apparatus. Remove all ignition sources. Do NOT wash away into sewer. Collect leaking and spilled liquid in sealable containers as far as possible. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations.

1. remove all ignition sources. 2. ventilate area of spill or leak. 3. for small quantities, absorb on paper towels, evaporate in safe place (such as fume hood). allow sufficient time for evaporating vapors to completely clear hood ductwork. burn paper in suitable location away from combustible material. 3. large quantities can be collected & atomized in suitable combustion chamber equipped with appropriate effluent gas cleaning device. pyridine should not be allowed to enter confined space, such as sewer, because of possibility of explosion.

NO open flames, NO sparks and NO smoking. Closed system, ventilation, explosion-proof electrical equipment and lighting. Do NOT use compressed air for filling, discharging, or handling. Handling in a well ventilated place. Wear suitable protective clothing. Avoid contact with skin and eyes. Avoid formation of dust and aerosols. Use non-sparking tools. Prevent fire caused by electrostatic discharge steam.

Fireproof. Separated from strong oxidants and strong acids. Cool. Dry. Well closed.OUTSIDE OR DETACHED STORAGE IS PREFERABLE. ISOLATE FROM POWERFUL OXIDIZING MATERIALS AND ACIDS.

Occupational Exposure limit values

Biological limit values

Eye/face protection

Skin protection

Respiratory protection

Thermal hazards

Decomposes on burning. This produces toxic fumes of nitrogen oxides and hydrogen cyanide. The substance is a weak base. Reacts violently with strong oxidants and strong acids.

Mixtures with formamide + iodine + sulfur trioxide are storage hazards, releasing carbon dioxide & sulfuric acid.

Pyridine is a flammable ... liquid.The vapour is heavier than air and may travel along the ground; distant ignition possible.PYRIDINE is a base. Reacts exothermically with acids. During preparation of a complex of pyridine with chromium trioxide, an acid, the proportion of chromium trioxide was increased. Heating from this acid-base reaction led to an explosion and fire [MCA Case History 1284 1967]. A 0.1% solution of pyridine (or other tertiary amine) in maleic anhydride at 185°C gives an exothermic decomposition with rapid evolution of gas [Chem Eng. News 42(8); 41 1964]. Mixing pyridine in equal molar portions with any of the following substances in a closed container caused the temperature and pressure to increase: chlorosulfonic acid, nitric acid (70%), oleum, sulfuric acid (96%), or propiolactone [NFPA 1991]. The combination of iodine, pyridine, sulfur trioxide, and formamide developed a gas over pressurization after several months. This arose from the slow formation of sulfuric acid from external water, or from dehydration of the formamide to hydrogen cyanide. Ethylene oxide and SO2 can react violently in pyridine solution with pressurization if ethylene oxide is in excess (Nolan, 1983, Case History 51).

no data available

Pyridine reacts violently with chlorosulfonic acid, chromic acid, maleic anhydride, nitric acid, fuming sulfuric acid, perchromates, beta-propiolactone, silver perchlorate, & sulfuric acid.

When pyridine is heated to decomposition, cyanide fumes are released.

Acute toxicity

• Oral: LD50 - rat - > 800 - < 1 600 mg/kg bw.
• Inhalation: LC50 - rat (male) - 4 900 ppm.
• Dermal: LD50 - rabbit - > 1 000 - < 2 000 mg/kg bw.

Skin corrosion/irritation

Serious eye damage/irritation

Respiratory or skin sensitization

Germ cell mutagenicity

Carcinogenicity

Reproductive toxicity

STOT-single exposure

STOT-repeated exposure

Aspiration hazard

• Toxicity to fish: EC50 - Danio rerio (previous name: Brachydanio rerio) - > 560 - < 1 000 mg/L - 96 h.
• Toxicity to daphnia and other aquatic invertebrates: EC50 - Daphnia magna - 320 mg/L - 48 h.
• Toxicity to algae: EC50 - Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) - 320 mg/L - 72 h.
• Toxicity to microorganisms: NOEC - activated sludge - 20 mg/L - 28 d.

Results of biodegradability screening tests for pyridine using sewage or activated sludge inocula give mixed results ranging from rapid to no degradation(1-5,7). Although biodegradability is improved in longer tests employing a more vigorous inocula, sometimes the same test gives disparate results(1-4,7). Variations in the particular sewage or activated sludge inoculum would affect test results. One investigator obtained results ranging from 97% degradation in 6 days to no degradation in 30 days in 6 different standard tests(1). After a preincubation step was added to one test in which no degradation was observed in 19 days, degradability increased to 91%(3). However the closed bottle test which employs only a drop of sewage effluent as an inoculum, registered no degradation even with a preincubation step(1,3). Tests that were designed to simulate biological treatment plants resulted in complete and rapid removal of pyridine(1,9). In one test that employed a soil suspension as an inoculum, 100% degradation was obtained in 66-170 days(6). When this test was repeated under anaerobic conditions, degradation was more rapid(6). Complete degradation was obtained in 32-66 days(6). When 2 micromoles/g of pyridine was incubated with a silt loam soil, 11.7% remained after 4 days and none remained after 8 days(8). The biodegradation rate constant for pyridine in water was 0.0033 - 0.018 per hour which corresponds to half-lives of 39-210 hours(10).

The bioconcentration factor in guppies exposed to an unspecified concentration of pyridine over a 2-day incubation period was 88(1). According to a classification scheme(2), this BCF suggests the bioconcentration in aquatic organisms moderate.

The Koc of pyridine is estimated as 50(SRC), using a measured log Kow of 0.65(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that pyridine is expected to have high mobility in soil. The pKa of pyridine is 5.23(4), which indicates that pyridine will partially exist in the protonated form under acidic conditions and cations adsorb more strongly to soil surfaces than neutral molecules(SRC). The adsorption of pyridine to a basic subsoil (pH 8.15, 0.58% organic carbon) is negligible, while in an acidic subsoil (pH 4.85, O.24% organic carbon), the Freundlich adsorption constant was measured to be 5.78 and the slope 0.679(5). This suggests a cationic adsorption mechanism as pyridine is predominantly in its protonated form. Pyridine adsorbs to colloidal particles of sodium montmorillonite and kaolinite, a process which is attributed to cation exchange and is a function of pH(5). Adsorption is at a minimum at pH 1 and 11 and reaches a maximum at pH 4 for the montmorillonite and pH 5.5 for the kaolinite where the adsorption constants are 60 and 10, respectively(6).

no data available

Product

Contaminated packaging

no data available

no data available

Information on revision

Abbreviations and acronyms

• CAS: Chemical Abstracts Service
• ADR: European Agreement concerning the International Carriage of Dangerous Goods by Road
• RID: Regulation concerning the International Carriage of Dangerous Goods by Rail
• IMDG: International Maritime Dangerous Goods
• IATA: International Air Transportation Association
• TWA: Time Weighted Average
• STEL: Short term exposure limit
• LC50: Lethal Concentration 50%
• LD50: Lethal Dose 50%
• EC50: Effective Concentration 50%

References

• IPCS - The International Chemical Safety Cards (ICSC), website: http://www.ilo.org/dyn/icsc/showcard.home
• HSDB - Hazardous Substances Data Bank, website: https://toxnet.nlm.nih.gov/newtoxnet/hsdb.htm
• IARC - International Agency for Research on Cancer, website: http://www.iarc.fr/
• eChemPortal - The Global Portal to Information on Chemical Substances by OECD, website: http://www.echemportal.org/echemportal/index?pageID=0&request_locale=en
• CAMEO Chemicals, website: http://cameochemicals.noaa.gov/search/simple
• ChemIDplus, website: http://chem.sis.nlm.nih.gov/chemidplus/chemidlite.jsp
• ERG - Emergency Response Guidebook by U.S. Department of Transportation, website: http://www.phmsa.dot.gov/hazmat/library/erg
• Germany GESTIS-database on hazard substance, website: http://www.dguv.de/ifa/gestis/gestis-stoffdatenbank/index-2.jsp
• ECHA - European Chemicals Agency, website: https://echa.europa.eu/

Other Information

Pyridine can normally be detected by odour at levels well below the TLV.However, perception of the odour may decline quickly.Depending on the degree of exposure, periodic medical examination is suggested.