Vinyl Chloride

2021-12-17

Vinyl chloride is the organochloride with the formula H2C:CHCl. It is also called vinyl chloride monomer, or VCM. This colourless compound is an important industrial chemical chiefly used to produce the polymer polyvinyl chloride (PVC). At ambient pressure and temperature, vinyl chloride is a gas with a sickly sweet odour. It is highly toxic, flammable and carcinogenic. [1]

Uses [2]

Vinyl chloride is used to make polyvinyl chloride (PVC). PVC is used to make a variety of products, including plastics, hoses, pipes and fittings for outdoor irrigation, wire and cable coatings, packaging materials, furniture and automobile upholstery, flooring, windows, credit or ATM cards, wall coverings, house wares, outdoor furniture, plastic containers, wrapping film, automotive parts and many others. In the past VCM has been used as a refrigerant.

In the Environment [3]

  • Liquid vinyl chloride evaporates easily.
  • Vinyl chloride in water or soil evaporates rapidly if it is near the surface.
  • Vinyl chloride in the air breaks down in a few days to other substances, some of which can be harmful.
  • Small amounts of vinyl chloride can dissolve in water.
  • Vinyl chloride is unlikely to build up in plants or animals that you might eat.

Sources & Routes of Exposure [2]

Sources of Emission

  • Industry sources: Industries that manufacture or use vinyl chloride in production are the primary sources of this substance. Some of these industries include the chemical industry (for the manufacture of PVC and other chemicals) and the plastics industry. Emissions or vinyl chloride are primarily to air, with a small percentage to water.
  • Diffuse sources: Landfills which contain vinyl chloride or other chlorinated hydrocarbons will release vinyl chloride. The treatment of wastewater containing vinyl chloride or chlorinated hydrocarbons may release vinyl chloride.
  • Natural sources: vinyl chloride does not form naturally in the environment.
  • Transport sources: There are no sources of vinyl chloride that arise from transport.
  • Consumer products: Many consumer products are made from or contain PVC. New PVC products may have trace amounts of vinyl chloride seep from new plastic parts.

Routes of Exposure

The most likely exposure to vinyl chloride will occur in a workplace that uses this substance, by breathing contaminated air, or by contact with the eyes or skin. Exposure can also occur by breathing vinyl chloride released from hazardous waste sites, landfills, or by drinking water from contaminated bodies of water. Although such a situation is possible, it is not considered likely.

Health Effects [3]

Acute Effects

  • Acute exposure of humans to high levels of vinyl chloride via inhalation in humans has resulted in effects on the CNS, such as dizziness, drowsiness, headaches, and giddiness.
  • Vinyl chloride is reported to be slightly irritating to the eyes and respiratory tract in humans.
  • Acute exposure to extremely high levels of vinyl chloride has caused loss of consciousness, lung and kidney irritation, and inhibition of blood clotting in humans and cardiac arrhythmias in animals.
  • Tests involving acute exposure of mice have shown vinyl chloride to have high acute toxicity from inhalation exposure.

Chronic Effects

  • Liver damage may result in humans from chronic exposure to vinyl chloride, through both inhalation and oral exposure.
  • A small percentage of individuals occupationally exposed to high levels of vinyl chloride in air have developed a set of symptoms termed “vinyl chloride disease,” which is characterised by Raynaud’s phenomenon (fingers blanch and numbness and discomfort are experienced upon exposure to the cold), changes in the bones at the end of the fingers, joint and muscle pain, and scleroderma-like skin changes (thickening of the skin, decreased elasticity, and slight oedema).
  • CNS effects (including dizziness, drowsiness, fatigue, headache, visual and/or hearing disturbances, memory loss, and sleep disturbances) as well as peripheral nervous system symptoms (peripheral neuropathy, tingling, numbness, weakness, and pain in fingers) have also been reported in workers exposed to vinyl chloride.
  • Animal studies have reported effects on the liver, kidney, and CNS from chronic exposure to vinyl chloride.
  • EPA has established a Reference Concentration (RfC) of 0.1 milligrams per cubic metre, and a Reference Dose (RfD) of 0.003 milligrams per kilogram per day for vinyl chloride.

Reproductive/Developmental Effects

  • Several case reports suggest that male sexual performance may be affected by vinyl chloride. However, these studies are limited by lack of quantitative exposure information and possible co-occurring exposure to other chemicals.
  • Several epidemiological studies have reported an association between vinyl chloride exposure in pregnant women and an increased incidence of birth defects, while other studies have not reported similar findings.
  • Epidemiological studies have suggested an association between men occupationally exposed to vinyl chloride and miscarriages in their wives’ pregnancies although other studies have not supported these findings.
  • Testicular damage and decreased male fertility have been reported in rats exposed to low levels for up to 12 months.
  • Animal studies have reported decreased foetal weight and birth defects at levels that are also toxic to maternal animals in the offspring of rats exposed to vinyl chloride through inhalation.

Cancer Risk

  • Inhaled vinyl chloride has been shown to increase the risk of a rare form of liver cancer (angiosarcoma of the liver) in humans.
  • Animal studies have shown that vinyl chloride, via inhalation, increases the incidence of angiosarcoma of the liver and cancer of the liver.
  • Several rat studies show a pronounced early-life susceptibility to the carcinogenic effect of vinyl chloride, i.e., early exposures are associated with higher liver cancer incidence than similar or much longer exposures that occur after maturity.
  • EPA has classified vinyl chloride as a Group A, human carcinogen.
  • EPA uses mathematical models, based on animal studies, to estimate the probability of a person developing cancer from breathing air containing a specified concentration of a chemical. EPA has calculated an inhalation unit risk estimate of 8.8 × 10-6 (µg/m3)-1 for lifetime exposure to vinyl chloride. Please see IRIS for current information.
  • EPA has calculated an oral cancer slope factor of 1.5 (mg/kg/d)-1 for lifetime exposure to vinyl chloride.

Safety [4]

First Aid Measures

  • Eye Contact: Check for and remove any contact lenses. Immediately flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical attention immediately.
  • Skin Contact: In case of contact, immediately flush skin with plenty of water for at least 15 minutes while removing contaminated clothing and shoes. To avoid the risk of static discharges and gas ignition, soak contaminated clothing thoroughly with water before removing it. Wash clothing before reuse. Clean shoes thoroughly before reuse. Get medical attention immediately.
  • Frostbite: Try to warm up the frozen tissues and seek medical attention.
  • Inhalation: Move exposed person to fresh air. If not breathing, if breathing is irregular or if respiratory arrest occurs, provide artificial respiration or oxygen by trained personnel. Loosen tight clothing such as a collar, tie, belt or waistband. Get medical attention immediately.
  • Ingestion: As this product is a gas, refer to the inhalation section.

Fires & Explosion Information

  • vinyl chloride is flammable
  • Auto-ignition temperature is 471.85°C (81.3°F)
  • Flash point: open cup -79.15°C (-10.5°F).
  • In case of fire, use water spray (fog), foam or dry chemical.
  • In case of fire, allow gas to burn if flow cannot be shut of immediately. Apply water from a safe distance to cool container and protect surrounding area.
  • If involved in fire, shut off flow immediately if it can be done without risk.
  • In a fire or if heated, a pressure increase will occur and the container may burst, with the risk of a subsequent explosion.
  • Fire fighters should wear appropriate protective equipment and self-contained breathing apparatus (SCBA) with a full face-piece operated in positive pressure mode.

Exposure Controls & Personal Protection

Engineering Controls

Use only with adequate ventilation. Use process enclosures, local exhaust ventilation or other engineering controls to keep worker exposure to airborne contaminants below any recommended or statutory limits. The engineering controls also need to keep gas, vapour or dust concentrations below any lower explosive limits. Use explosion proof ventilation equipment.

Personal Protective Equipment

The following personal protective equipment is recommended when handling vinyl chloride:

  • Safety eyewear complying with an approved standard should be used when a risk assessment indicates this is necessary to avoid exposure to liquid splashes, mists or dusts.
  • Personal protective equipment for the body should be selected based on the task being performed and the risks involved and should be approved by a specialist before handling this product.
  • Use a properly fitted, air-purifying or air-fed respirator complying with an approved standard if a risk assessment indicates this is necessary. Respirator selection must be based on known or anticipated exposure levels, the hazards of the product and the safe working limits of the selected respirator.
  • Chemical-resistant, impervious gloves complying with an approved standard should be
  • worn at all times when handling chemical products if a risk assessment indicates this is
  • necessary.

In case of a large spill: Self-contained breathing apparatus (SCBA) should be used to avoid inhalation of the product.

Regulation [2,5,6]

United States

OSHA: The United States Occupational Safety & Health Administration has set the following Permissible Exposure Limit (PEL) for vinyl chloride:

  • General Industry: 29 CFR 1910.1017 – Vinyl chloride – 1 ppm TWA; 0.5 ppm Action Level
  • Construction Industry: 29 CFR 1926.1117 – Vinyl chloride requirements identical to 1910.1017
  • Maritime: 29 CFR 1915.1017 – Vinyl chloride requirements identical to 1910.1017

ACGIH: The American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV) for vinyl chloride is 1 ppm TWA; Appendix A1 – Confirmed Human Carcinogen

NIOSH: The National Institute for Occupational Safety and Health (NIOSH) has classified vinyl chloride as Appendix A – NIOSH Potential Occupational Carcinogens

EPA: The Environmental Protection Agency regulates vinyl chloride in drinking water, food, and air. The EPA requires that the amount of vinyl chloride in drinking water not exceed 0.002 milligrams per litre (mg/L) of water.

FDA: The Food and Drug Administration (FDA) regulates the vinyl chloride content of various plastics. These include plastics that carry liquids and plastics that contact food. The limits for vinyl chloride content vary depending on the nature of the plastic and its use.

Australia

Safe Work Australia: Currently, the eight-hour time weighted average (TWA) exposure limit is 13 milligrams of vinyl chloride per cubic metre of air. A 15-minute short-term exposure limit (STEL) has not been recommended.

Australian Drinking Water Guidelines: In 2004, the National Health and Medical Research Council (NHMRC) and National Resource Management Ministerial Council (NRMMC) established that no safe concentration level can be confidently set for vinyl chloride, however the concentration should be less than 0.0003 milligrams per litre of water, the limit of scientific determination for this substance.

Reference

http://en.wikipedia.org/wiki/Vinyl_chloride

http://www.npi.gov.au/resource/vinyl-chloride-monomer-vcm

http://www.epa.gov/ttn/atw/hlthef/vinylchl.html

http://www.airgas.com/documents/pdf/001067.pdf

http://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=281&tid=51

https://www.osha.gov/dts/chemicalsampling/data/CH_275395.html