Hazard symbol - AbsoluteAstronomy.com

Hazard symbols are recognizable symbol

Symbol

A symbol is something which represents an idea, a physical entity or a process but is distinct from it. The purpose of a symbol is to communicate meaning. For example, a red octagon may be a symbol for "STOP". On a map, a picture of a tent might represent a campsite. Numerals are symbols for...

s designed to warn about hazardous materials or locations. The use of hazard symbols is often regulated by law and directed by standards organization

Standards organization

A standards organization, standards body, standards developing organization , or standards setting organization is any organization whose primary activities are developing, coordinating, promulgating, revising, amending, reissuing, interpreting, or otherwise producing technical standards that are...

s. Hazard symbols may appear with different colors, backgrounds, borders and supplemental information in order to signify the type of hazard.

Types of hazard symbols

Name	Symbol	Unicode
Toxic sign	☠	U+2620
Caution sign	☡	U+2621
Radioactivity Radioactive decay Radioactive decay is the process by which an atomic nucleus of an unstable atom loses energy by emitting ionizing particles . The emission is spontaneous, in that the atom decays without any physical interaction with another particle from outside the atom... sign	☢	U+2622
Ionizing radiation Ionizing radiation Ionizing radiation is radiation composed of particles that individually have sufficient energy to remove an electron from an atom or molecule. This ionization produces free radicals, which are atoms or molecules containing unpaired electrons... sign	?	?
Non-ionizing radiation Non-ionizing radiation Non-ionizing radiation refers to any type of electromagnetic radiation that does not carry enough energy per quantum to ionize atoms or molecules—that is, to completely remove an electron from an atom or molecule... sign	?	?
Biohazard Biological hazard Biological hazards, refer to biological substances that pose a threat to the health of living organisms, primarily that of humans. This can include medical waste or samples of a microorganism, virus or toxin that can impact human health. It can also include substances harmful to animals... sign	☣	U+2623
Warning sign Warning sign A traffic warning sign is a type of traffic sign that indicates a hazard ahead on the road that may not be readily apparent to a driver.In most countries, they usually take the shape of an equilateral triangle with a white background and a thick red border...	⚠	U+26A0
High voltage High voltage The term high voltage characterizes electrical circuits in which the voltage used is the cause of particular safety concerns and insulation requirements... sign	⚡	U+26A1
Magnetic field Magnetic field A magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude ; as such it is a vector field.Technically, a magnetic field is a pseudo vector;... symbol	?	?
Chemical weapon Chemical warfare Chemical warfare involves using the toxic properties of chemical substances as weapons. This type of warfare is distinct from Nuclear warfare and Biological warfare, which together make up NBC, the military acronym for Nuclear, Biological, and Chemical... symbol	?	?
Laser Laser A laser is a device that emits light through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation... hazard sign	?	?
Optical radiation	?	?
Tsunami hazard sign	?	?

More hazard signs can be found on the list of DIN 4844-2 warning signs

Radioactive trefoil symbol

The international radiation symbol (also known as trefoil

Trefoil

Trefoil is a graphic form composed of the outline of three overlapping rings used in architecture and Christian symbolism...

) first appeared in 1946, at the University of California, Berkeley

University of California, Berkeley

The University of California, Berkeley , is a teaching and research university established in 1868 and located in Berkeley, California, USA...

Radiation Laboratory. At the time, it was rendered as magenta

Magenta

Magenta is a color evoked by light stronger in blue and red wavelengths than in yellowish-green wavelengths . In light experiments, magenta can be produced by removing the lime-green wavelengths from white light...

, and was set on a blue

Blue

Blue is a colour, the perception of which is evoked by light having a spectrum dominated by energy with a wavelength of roughly 440–490 nm. It is considered one of the additive primary colours. On the HSV Colour Wheel, the complement of blue is yellow; that is, a colour corresponding to an equal...

background. (See right.)
The modern version used in the U.S. is magenta against a yellow background, and it is drawn with a central circle of radius R, an internal radius of 1.5R and an external radius of 5R for the blades, which are separated from each other by 60°. The trefoil is black in the international version, which is also acceptable in the U.S.

On February 15, 2007, the IAEA and the ISO

International Organization for Standardization

The International Organization for Standardization , widely known as ISO, is an international standard-setting body composed of representatives from various national standards organizations. Founded on February 23, 1947, the organization promulgates worldwide proprietary, industrial and commercial...

announced a new ionizing radiation

Ionizing radiation

Ionizing radiation is radiation composed of particles that individually have sufficient energy to remove an electron from an atom or molecule. This ionization produces free radicals, which are atoms or molecules containing unpaired electrons...

symbol to supplement the traditional trefoil symbol. The new symbol is aimed at alerting anyone, anywhere to the potential dangers of being close to a large source of ionizing radiation. Experts have felt that the trefoil symbol had little intuitive value and was less likely to be recognized by those not educated in its significance. According to the IAEA, in a survey conducted at an international school, many children mistook the trefoil for a non-threatening propeller. Hence, the Agency, along with the International Organization for Standardization

International Organization for Standardization

has devised this symbol for sealed radiation sources. It depicts, on a red background, a black colored trefoil radiating waves, a skull and crossbones, and a person running away from the scene. The radiating trefoil suggests the presence of radiation and the red background and skull and crossbones warn of the danger. The person running away from the scene suggests the action of avoiding the labeled material. The symbol had been tested in countries with different population of varying groups, ages, and educational backgrounds to ensure that it clearly conveys the message “Danger: stay away.” The new symbol is not intended to be generally visible, but appear on device internals housing radiation sources so that if someone attempts to disassemble a device it provides an explicit warning not to proceed any further.

Biohazard sign

Developed by the Dow Chemical Company

Dow Chemical Company

The Dow Chemical Company is a multinational corporation headquartered in Midland, Michigan, United States. As of 2007, it is the second largest chemical manufacturer in the world by revenue and as of February 2009, the third-largest chemical company in the world by market capitalization .Dow...

in 1966 for their containment products.

According to Charles Baldwin, an environmental-health engineer who contributed to its development: "We wanted something that was memorable but meaningless, so we could educate people as to what it means." In an article in Science

Science (journal)

Science is the academic journal of the American Association for the Advancement of Science and is one of the world's top scientific journals....

in 1967, the symbol was presented as the new standard for all biological hazards ("biohazards"). The article explained that over 40 symbols were drawn up by Dow artists, and all of the symbols investigated had to meet a number of criteria: "(i) striking in form in order to draw immediate attention; (ii) unique and unambiguous, in order not to be confused with symbols used for other purposes; (iii) quickly recognizable and easily recalled; (iv) easily stenciled; (v) symmetrical, in order to appear identical from all angles of approach; and (vi) acceptable to groups of varying ethnic backgrounds." The chosen scored the best on nationwide testing for memorability.

It is used in the labeling of biological materials that carry a significant health risk, including viral samples and used hypodermic needles.
It was also somewhat famous for being the "insignia" for the 2002 horror film, 28 Days Later

28 Days Later

28 Days Later is an acclaimed 2002 British horror film directed by Danny Boyle. The screenplay was written by Alex Garland, and the film stars Cillian Murphy, Naomie Harris, Brendan Gleeson, Megan Burns, and Christopher Eccleston...

Drawing

All parts of the biohazard sign can be drawn with a compass and straightedge

Compass and straightedge

Compass-and-straightedge or ruler-and-compass construction is the construction of lengths, angles, and other geometric figures using only an idealized ruler and compass....

. The basic outline of the symbol is a plain trefoil

Trefoil

Trefoil is a graphic form composed of the outline of three overlapping rings used in architecture and Christian symbolism...

, which is three circles overlapping each other equally like in a triple venn diagram

Venn diagram

Venn diagrams or set diagrams are diagrams that show all possible logical relations between a finite collection of sets . Venn diagrams were conceived around 1880 by John Venn...

with the overlapping parts erased. The diameter of the overlapping part is equal to half the radius of the three circles. Then three inner circles are drawn in with 2/3 radius of the original circles so that it is tangent

Tangent

In geometry, the tangent line to a plane curve at a given point is the straight line that "just touches" the curve at that point. More precisely, a straight line is said to be a tangent of a curve at a point on the curve if the line passes through the point on the curve and has slope where f...

to the outside three overlapping circles. A tiny circle in center has a diameter

Diameter

In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...

1/2 of the radius of the three inner circle, and arcs

Arc (geometry)

In geometry, an arc is a closed segment of a differentiable curve in the two-dimensional plane; for example, a circular arc is a segment of the circumference of a circle...

are erased at 90°, 210°, 330°. The arcs of the inner circles and the tiny circle are connected by a line. Finally, the ring under is drawn from the distance to the perimeter

Perimeter

A perimeter is a path that surrounds an area. The word comes from the Greek peri and meter . The term may be used either for the path or its length - it can be thought of as the length of the outline of a shape. The perimeter of a circular area is called circumference.- Practical uses :Calculating...

of the equilateral triangle that forms between the centers of the three intersecting circles. An outer circle of the ring under is drawn and finally enclosed with the arcs from the center of the inner circles with a shorter radius from the inner circles.

Tattoos

A tattoo of the biohazard sign is recognized within the gay community to indicate the wearer is living with HIV

HIV

Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...

. The origins for this practice aren't clear, but they range from a response to William F. Buckley's call for the tattooing of HIV positive individuals to a few activists within ACT UP.

Poison sign

The skull-and-crossbones symbol, consisting of a human skull

Human skull

The human skull is a bony structure, skeleton, that is in the human head and which supports the structures of the face and forms a cavity for the brain.In humans, the adult skull is normally made up of 22 bones...

and two bones crossed together under the skull, is today generally used as a warning of danger, particularly in regard to poison

Poison

In the context of biology, poisons are substances that can cause disturbances to organisms, usually by chemical reaction or other activity on the molecular scale, when a sufficient quantity is absorbed by an organism....

ous substances.

The symbol, or some variation thereof, specifically with the bones (or swords) below the skull, was also featured on the Jolly Roger

Jolly Roger

The Jolly Roger is any of various flags flown to identify a ship's crew as pirates. The flag most commonly identified as the Jolly Roger today is the skull and crossbones, a flag consisting of a human skull above two long bones set in an x-mark arrangement on a black field. This design was used by...

, the traditional flag

Flag

A flag is a piece of fabric with a distinctive design that is usually rectangular and used as a symbol, as a signaling device, or decoration. The term flag is also used to refer to the graphic design employed by a flag, or to its depiction in another medium.The first flags were used to assist...

of Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

an and American

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

pirates. It is also used by Skull and Bones

Skull and Bones

Skull and Bones is an undergraduate senior or secret society at Yale University, New Haven, Connecticut. It is a traditional peer society to Scroll and Key and Wolf's Head, as the three senior class 'landed societies' at Yale....

, a secret society

Secret society

A secret society is a club or organization whose activities and inner functioning are concealed from non-members. The society may or may not attempt to conceal its existence. The term usually excludes covert groups, such as intelligence agencies or guerrilla insurgencies, which hide their...

at Yale University

Yale University

Yale University is a private, Ivy League university located in New Haven, Connecticut, United States. Founded in 1701 in the Colony of Connecticut, the university is the third-oldest institution of higher education in the United States...

, as well as the international male collegiate fraternity Phi Kappa Sigma

Phi Kappa Sigma

Phi Kappa Sigma is an international all-male college social fraternity. Its members are known as "Phi Kaps", "Skulls" and sometimes "Skullhouse", the latter two because of the skull and crossbones on the Fraternity's badge and coat of arms. Phi Kappa Sigma was founded by Dr. Samuel Brown Wylie...

. It is also part of the WHMIS home symbols placed on containers to inform that the contents are substances are poisonous.

In the United States, due to concerns that the skull and bones symbol's association with pirates encourages children to play with toxic materials, the Mr. Yuk

Mr. Yuk

Mr. Yuk is a trademarked graphic image, created by the Children's Hospital of Pittsburgh, and widely employed in the United States in labeling of substances that are poisonous if ingested.-Overview:...

symbol is also used to denote poison.

Warning sign

On warning signs, an exclamation mark is often used to draw attention to a warning of danger, hazards, and the unexpected. In Europe, this type of sign is used if there are no other appropriate signs to denote a hazard. When used in traffic signs a plate describing the hazard must be present. On an upright sign it is usually mounted under the exclamation mark.

Chemical hazard

A chemical hazard label is a pictogram

Pictogram

A pictograph, also called pictogram or pictogramme is an ideogram that conveys its meaning through its pictorial resemblance to a physical object. Pictographs are often used in writing and graphic systems in which the characters are to considerable extent pictorial in appearance.Pictography is a...

applied to containers of dangerous chemical compound

Chemical compound

A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...

s to indicate the specific risk, and thus the required precautions. There are several systems of labels.

The U.S.-based National Fire Protection Association

National Fire Protection Association

The National Fire Protection Association is a United States trade association that creates and maintains private, copywrited, standards and codes for usage and adoption by local governments...

(NFPA) has a standard NFPA 704

NFPA 704

NFPA 704 is a standard maintained by the U.S.-based National Fire Protection Association. It defines the colloquial "fire diamond" used by emergency personnel to quickly and easily identify the risks posed by nearby hazardous materials...

using a diamond with four colored sections each with a number indicating severity 0—4 (0 for no hazard, 4 indicates a severe hazard). The red section denotes flammability. The blue section denotes health risks. Yellow represents reactivity (tendency to explode). The white section denotes special hazard information. This label is used primarily in the USA.

In Europe, another standard is used, as fixed in the European Agreement concerning the International Carriage of Dangerous Goods by Road

European Agreement concerning the International Carriage of Dangerous Goods by Road

The European Agreement concerning the International Carriage of Dangerous Goods by Road, commonly known as ADR , governs transnational transport of hazardous materials.Launched in Geneva on 30 September 1957 under the aegis of the United...

. Vehicles carrying dangerous goods have to be fitted with orange signs, where the lower number identifies the substance, while the upper number is a key for the threat it may pose. These symbols cannot be readily interpreted without the aid of a key.

European hazard symbols


Example of European warning for flammable substances

Non-standard warning signs

A large number of warning signs of non-standard designs, such as the one on the right at the Beromünster Reserve Broadcasting Tower, are in use around the world.

External links

Hazchem Guide from The National Chemical Emergency Centre
Safety symbols collection for hazard alerts A symbol library which offers various signs in the GIF and EPS formats. Licensed for free use only for writing technical documents.
European Chemicals Bureau
Directive 2001/59/EC
Hazchem panel information

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.