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PAH

Polynuclear aromatic hydrocarbon; also called polycyclic aromatic hydrocarbon, a component of oil. PAHs are associated with demonstrated toxic effects.

pancakes

Isolated, roughly circular patches of oil ranging in size from a few feet across to hundreds of yards (or meters) in diameter. Sheen may or may not also be present.

PCBs

Polychlorinated biphenyls. A group of synthetic, organic chlorinated aromatic hydrocarbons having various applications in industry. PCBs are highly toxic, poisonous, and potentially carcinogenic (capable of causing cancer) environmental pollutants known to cause skin diseases. They tend to accumulate in animal tissues and are suspected of causing birth defects and cancer.

pelagic

Refers to fish and animals that live in the open sea, away from the sea bottom. Contrast with benthic.

penetration

The movement of spilled oil into shoreline sediments.

peroxidizable

Can slowly react with oxygen in the air or with oxidizers (oxidizing agents) to eventually form potentially explosive, white crystalline peroxides.

persistent

A term used to describe a substance that will remain in the environment for a long period of time without being broken down into simpler chemicals or reduced to acceptable levels by natural physical or chemical biological processes.

personal protective equipment (PPE)

Any gear, clothing, or other equipment used to protect personnel from known and or suspected hazards on a site.

petroleum

Hydrocarbon materials found naturally underground, including crude oil, condensate, natural gasoline, natural gas liquids, liquefied petroleum gas, and liquid petroleum products.

pH

Measure of the acidity or alkalinity of a solution. At room temperature, a solution having a pH of 7 is neutral (neither acidic nor basic). Solutions with pHs greater than 7 are basic (alkaline); solutions with pHs below 7 are acidic.

pinniped

The group of marine mammals that includes seals, walruses, and sealions.

place of refuge

An area of sheltered water for a ship in distress or needing repairs.

POC

Point of contact.

point source pollution

Pollution originating at a particular place, such as a grounded ship or a sewage treatment plant, outfall, or other discharge pipe. See also non-point source pollution.

pollutant

Any material entering the water which is not a normal part of the local environment, or which is in a concentration that is not normal to the local environment.

POLREP

Pollution report. An initial report of a pollution incident (e.g., a spill or a potential release of an oil or chemical), issued by the U.S. Coast Guard.

polymer

The product of polymerization. Proteins, starches, cellulose and natural rubber are naturally occurring polymers; polystyrene, nylon, Teflon®, and synthetic rubber are synthetic polymers. See also polymerization.

polymerizable

Can react with itself. Polymerization reactions typically generate heat and could cause container to overpressurize, possibly leading to a fire or explosion.

polymerization

Chemical reaction in which small molecules join to form larger molecules; polymerization reactions typically release heat, and can cause containers to overpressurize.

pom-poms

Also called oil snares. Pom-pom shaped absorbents made of synthetic fibers that "attract" oil. Pom-poms are used individually or tied on long ropes and used to catch oil as it leaches from beaches and rocky areas. Strings of pom-poms are effective in collecting oil in rock or difficult to reach areas where the tide rises and falls.

pooled oil

Fresh oil or mousse that has accumulated to a thickness exceeding 1 cm.

pour point

The lowest temperature at which oil is observed to flow. At ambient temperatures that are below an oil's pour point, the oil will tend to be a semi-solid. An oil that is near or below its pour point generally cannot be pumped without heating, cannot be chemically dispersed, and will not readily penetrate into substrates such as gravel or cobble beaches.

ppb

Parts per billion. A unit of concentration used where low levels of concentration are significant, such as that of a gas or vapor in air (as molecules of chemical per billion molecules of air).

PPE

See Personal Protective Equipment.

ppm

Parts per million. A unit of concentration often used when measuring levels of pollutants in air and water. One ppm is 1 part in 1,000,000, which can be approximated by one teaspoon in 1,300 gallons. The common unit mg/liter is equal to ppm.

ppt

Parts per thousand. A unit of concentration often used to record the salinity of seawater. One ppt is 1 part in 1,000.

pressurization

Build up of pressure within a closed container. May cause container to explode.

prill

Small spherical or cylindrical pellets used in the fertilizer and explosive industry because they are convenient to handle (e.g., ammonium nitrate prills, often coated with wax because this salt tends to cake when hydrated).

PSI

Pounds per square inch; a unit of pressure measurement.

PSIG

Pounds per square inch gauge; pressure relative to atmospheric pressure.

pyrophoric

Any substance that ignites in the presence of air at or below ambient temperatures. Many pyrophoric materials react with moisture in the air to generate flammable hydrogen gas and enough heat to ignite the hydrogen. These are extremely dangerous fire hazards that are generally stored under an inert atmosphere or in a solvent like ether or kerosene that excludes air.

pyrotechnics

The manufacture of fireworks, signal flares, and so on, involving the mixture of different chemicals to achieve various visual and auditory effects. Chemicals used in pyrotechnics include many explosive inorganic compounds such as potassium nitrate, metal perchlorates, dichromate, powdered metals, and phosphorus.