White Phosphorus

2021-07-16

Phosphorus is a non-metallic chemical element with symbol P and atomic number 15. As a mineral, it is almost always present in its maximally oxidised state, as inorganic phosphate rocks. Elemental phosphorus exists in two major forms—white phosphorus and red phosphorus—but due to its high reactivity, phosphorus is never found as a free element on Earth. [1]

Pure white phosphorus is a colourless-to-white waxy solid, but commercial white phosphorus is usually yellow. Therefore, it is also known as yellow phosphorus. White phosphorus is also called phosphorus tetramer and has a garlic-like smell. In air, it catches fire at temperatures l0-15 degrees above room temperature. Because of its high reactivity with oxygen in air, white phosphorus is generally stored under water. White phosphorus does not occur naturally. Industries produce it from naturally occurring phosphate rocks. [2]

White phosphorus glows in the dark (when exposed to oxygen) with a very faint tinge of green and blue. [1]

Uses [2]

White phosphorus is used mainly for producing phosphoric acid and other chemicals. These chemicals are used to make fertilisers, additives in foods and drinks, cleaning compounds, and other products. Small amounts of white phosphorus have been used as rat and roach poisons and in fireworks. In the past, white phosphorus was used to make matches, but another chemical with fewer harmful health effects has since replaced it. In the military, white phosphorus is used in ammunitions such as mortar and artillery shells, and grenades.

In the Environment [3]

  • White phosphorus can enter the environment when it is made, used in manufacturing or by the military, or accidentally spilled during transport and storage.
  • It can be found in the water and bottom sediment of rivers and lakes near facilities that make or use it.
  • In the air, white phosphorus reacts rapidly with oxygen to produce relatively harmless chemicals within minutes.
  • In water, white phosphorus reacts with oxygen within hours or days.
  • In water with low oxygen, white phosphorus may degrade to a highly toxic compound called phosphine, which eventually evaporates to the air and is changed to less harmful chemicals.
  • White phosphorus can build up slightly in the bodies of fish that live in contaminated lakes or streams.
  • In soil, white phosphorus may stick to particles and be changed within a few days to less harmful compounds.
  • In deep soil or sediments with little oxygen, white phosphorus may remain unchanged for many years.

Sources & Routes of Exposure

Sources of Exposure [3]

  • Breathing contaminated air near a facility that is using white phosphorus.
  • Eating contaminated fish or game birds from sites containing white phosphorus.
  • Drinking or swimming in water that has been contaminated with white phosphorus.
  • Touching soil contaminated with white phosphorus.
  • If you work in industries that use or manufacture white phosphorus or munitions containing white phosphorus.

Routes of Exposure [4]

White phosphorus can be absorbed into the body by inhalation, ingestion, or skin contact. It is unknown whether systemic exposure can occur from eye contact.

Health Effects [5]

Acute Effects

  • Acute oral exposure to high levels of white phosphorus in humans is characterised by three stages: the first stage consists of gastrointestinal effects; the second stage is symptom-free and lasts about 2 days; the third stage consists of a rapid decline in condition with severe gastrointestinal (vomiting, abdominal cramps and pain), kidney, liver, cardiovascular, and CNS effects.
  • Acute inhalation exposure has resulted in respiratory tract irritation and coughing in humans.
  • Respiratory, liver, and kidney effects have been reported in animals acutely exposed to white phosphorus smoke via inhalation.
  • Dermal exposure to white phosphorus in humans may result in severe burns, which are necrotic, yellowish, fluorescent under ultraviolet light, and have a garlic-like odour.
  • Acute animal tests in rats and mice have shown white phosphorus to have extreme acute toxicity from oral exposure.

Chronic Effects

  • Chronic exposure to white phosphorus in humans results in necrosis of the jaw, termed “phossy jaw.” Progressive symptoms begin as a local inflammation or irritation and proceed to swelling, ulceration, and destruction of the jawbone with perforation to the sinus or nasal cavities and externally to the cheek.
  • In one occupational study, anaemia and leukopenia were observed.
  • Animal studies have reported effects on the blood from inhalation exposure to white phosphorus.
  • The Reference Dose (RfD) for white phosphorus is 0.00002 milligrams per kilogram body weight per day (mg/kg/d) based on reproductive effects (parturition mortality and forelimb hair loss in rats).
  • EPA has not established a Reference Concentration (RfC) for white phosphorus.
  • The California Environmental Protection Agency (CalEPA) has calculated an inhalation reference exposure level of 0.00007 milligrams per cubic metre (mg/m3) based on a route-to-route extrapolation of EPA’s RfD. The CalEPA reference exposure level is a concentration at or below which adverse health effects are not likely to occur.
  • ATSDR has calculated an acute inhalation minimal risk level (MRL) of 0.02 mg/m3 for white phosphorus smoke based on respiratory effects in humans. The MRL is an estimate of the daily human exposure to a hazardous substance that is likely to be without appreciable risk of adverse non-cancer health effects over a specified duration of exposure.

Reproductive/Developmental Effects

  • No information is available on the reproductive or developmental effects of white phosphorus in humans.
  • An animal study reported a high maternal mortality rate from oral exposure to white phosphorus.

Cancer Risk

  • No information is available on the carcinogenic effects of white phosphorus in humans or animals.
  • EPA has classified white phosphorus as a Group D, not classifiable as to human carcinogenicity.

Safety [6]

First Aid Measures

  • Inhalation: If adverse effects occur, remove to uncontaminated area. Give artificial respiration if not breathing. If breathing is difficult, qualified personnel should administer oxygen. If respiration or pulse has stopped, have a trained person administer Basic Life Support (Cardio-Pulmonary Resuscitation/Automatic External Defibrillator) and CALL FOR EMERGENCY SERVICES IMMEDIATELY.
  • Skin Contact: Immediately immerse contaminated areas under water. GET MEDICAL ATTENTION IMMEDIATELY. Keep contaminated area immersed in water until medical attention arrives. Remove contaminated clothing, jewellery and shoes. Discard contaminated clothing and footwear.
  • Eye Contact: Immediately flush eyes with a directed stream of water for at least 15 minutes, forcibly holding eyelids apart to ensure complete irrigation of all eye and lid tissues. Washing eyes within several seconds is essential to achieve maximum effectiveness. GET MEDICAL ATTENTION IMMEDIATELY.
  • Ingestion: Never give anything by mouth to an unconscious or convulsive person. If swallowed, do not induce vomiting. Give large amounts of water. If vomiting occurs spontaneously, keep airway clear. Give more water when vomiting stops. GET MEDICAL ATTENTION IMMEDIATELY.

Fires Information

  • Fire Hazard: Phosphorus poses a severe fire hazard. Will ignite on exposure to air. If allowed to dry, contaminated water may ignite.
  • Extinguishing Media: Use regular foam, water, wet sand or earth. Do not use alkaline-based extinguishing agents.
  • Fire Fighting: Move container from fire area if it can be done without risk. Cool containers with water spray until well after the fire is out. Do not scatter spilled material with high-pressure water streams. Avoid inhalation of material or combustion by-products. Wear NIOSH approved positive-pressure self-contained breathing apparatus operated in demand mode.
  • Flash Point: Spontaneously flammable
  • Autoignition Temperature: 86 F (30 C)
  • Hazardous Combustion Products: Phosphorus pentoxide, Oxides of phosphorus

Exposure Controls & Personal Protection

Engineering Controls

  • Use closed systems when possible.
  • General or local exhaust ventilation and other forms of engineering controls are the preferred means for controlling exposures.
  • Ensure compliance with applicable exposure limits.

Personal Protective Equipment

The following personal protective equipment is recommended when handling white phosphorus:

  • Eye Protection: Wear splash resistant safety goggles with a face shield. Provide an emergency eye wash fountain and quick drench shower in the immediate work area. A quick drench tank should be used if feasible.
  • Skin and Body Protection: Wear chemical resistant clothing and rubber boots when potential for contact with the material exists. In certain situations, a full body suit with hood and boots may provide short-term protection.
  • Hand Protection: Wear appropriate chemical resistant gloves.
  • Protective Material Types: Best Nitty Gritty(R), Aluminised Kevlar(R)
  • Respiratory Protection: Supplied air is required unless there is no phosphine gas or phosphorus pentoxide present. A NIOSH approved respirator with acid gas cartridges/N95 filters cartridges may be permissible under certain circumstances where airborne concentrations are expected to exceed exposure limits, or when symptoms have been observed that are indicative of overexposure. A respiratory protection program that meets 29 CFR1910.134 must be followed whenever workplace conditions warrant use of a respirator.

Regulation [3,7]

United States

EPA: The Environmental Protection Agency has listed white phosphorus as a Hazardous Air Pollutant. The EPA requires that spills or accidental releases into the environment of 1 pound or more of white phosphorus be reported to the EPA.

The National Institute for Occupational Safety and Health (NIOSH), the Occupational Safety and Health Administration (OSHA), and the American Conference of Governmental Industrial Hygienists (ACGIH) have all set the inhalation exposure limit for white phosphorus in the workplace during an 8-hour workday at 0.1 milligram of white phosphorus per cubic metre of air (0.1 mg/m³).

Australia

Safe Work Australia: Safe Work Australia has set an 8-hour Time Weighted Average (TWA) concentration of 0.1 mg/m³

References

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

http://www.atsdr.cdc.gov/toxprofiles/tp103.pdf

http://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=284&tid=52

http://www.cdc.gov/niosh/ershdb/EmergencyResponseCard_29750025.html

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

http://archpdfs.lps.org/Chemicals/Phosphorus_white.pdf

http://www.safeworkaustralia.gov.au/sites/SWA/about/Publications/Documents/639/Workplace_Exposure_Standards_for_Airborne_Contaminants.pdf