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Tuesday, August 20, 2013

Symbols of Danger: The Radiation Trefoil Failure.

Herbie Goes Bananas and Other Makings of a Disaster

On September 13, 1987, a security guard at the defunct Instituto Goiano de Radioterapia (IGR), a private radiotherapy institute in the Brazilian state of Goias, decided to take a sick day in order to check out Herbie Goes Bananas with his family at the local cinema.  His decision to take in a piece of first world movie franchise detritus with a south-of-the-border flavor would be the gateway to a radiological disaster.

The source of this disaster was another first world commercial good: a radiological therapy machine sitting in the ruins of the IGR institute.  Buried within the radiological therapy machine was its delivery mechanism: a salt shaker-sized capsule of highly radioactive cesium.  While the security guard took the day off, opportunistic scavengers entered the unguarded facility. They discovered the machine and wheelbarrowed it back to their neighborhood. 

Over the next two weeks, several people progressively disassembled the machine for scrap, separated the cesium capsule from the machine, and eventually pried open the leaden capsule.   Scrapyard workers were fascinated by the glowing fluorescence of the cesium contents, and exchanged the cesium among friends and family.   

The Radiation Trefoil Symbol and its Development

The trefoil symbol is striking and memorable.  Its stark yellow and black color scheme strikes fear in most individuals who have even a remote understanding or awareness of radioactivity. 

Its visual design came to life in 1946 at the University of California Radiation Laboratory in Berkeley.  Nels Garden, head of the Health Chemistry Group at the Radiation Laboratory, described the design considerations:

A number of people in the group took an interest in suggesting different motifs, and the one arousing the most interest was a design which was supposed to represent activity radiating from an atom.

He went on to talk about the economics of printing and distributing the symbol in the original color scheme of a magenta trefoil on a blue (later, yellow) background:  

It was distinctive and did not conflict with any color code that we were familiar with.  Another factor was its cost…the high cost will deter others from using this color promiscuously.

At first, the trefoil symbol appealed most to those who were familiar with the relatively new science of nuclear physics.  Over time, that symbol grew in recognition and popularity through pulp science fiction and civil defense programming.  

It’s possible that the original designers of the symbol wouldn’t have foreseen the ubiquity of the trefoil, nor would they have imagined the extent of radioactive materials in today’s scientific and commercial equipment. Although the trefoil persisted and became recognizable in radiological material producer countries, in radiological material consumer countries, it was a different story.  

Here we have a poignant and terrible reminder of how we need to, as information designers, distinguish contextual and learned semiotics from those that are intuitive, and to apply them correctly.  Radiological components began to appear in consumer country garbage dumps, where significant underground economies thrived.  People in the consumer countries did not recognize the symbol.  Removed from its context, the symbol standing alone did not produce any intuitive understanding or emotional reaction.  A five-year International Atomic Energy Agency (IAEA) study surveyed the population of eleven countries and found that most respondents were unfamiliar with the meaning of the trefoil symbol; only 6% of respondents in Kenya, India and Brazil were familiar with the symbol’s meaning. 

Furthermore, manufacturing, assembly and other product management during the 1970’s and 1980’s had only begun to consider the life-cycle of any consumer or commercial good, much less so deviations from its expected use.  Medical device manufacturers expected that their machines would be acquired, used, and disposed of in the normal commercial context of a first world country.  Consequently, labeling was scarce and was designed with the entire assembly in mind, rather than the assembly’s individual components.

The Consequences

During the two weeks after the original scavengers removed the capsule and allowed the capsule's contents to be spread through their neighborhood, many more people came into contact with the cesium.  Adults used it as decoration; children used it as a plaything.   The result: by the time local authorities pieced together the related incidents of  radiation sickness improperly diagnosed as food poisoning or other common maladies, over 250 people became officially documented casualties from high levels of radiation.  Eventually, four people died from the incident, including a six year old girl.  In addition, over 100,000 people flooded and overwhelmed local hospitals in response to local, state, national and international interventions.  

Recovery and cleanup operations were substantial, given the widespread dispersion of the substance.  Cesium is water soluble; although the incident did not occur during a rainy season, there were still grave concerns about the extent of contamination.  Eventually, local and international authorities had to completely demolish several houses, remove acres of topsoil, and conduct other disposal operations.  

The three doctors who were principals of the IGR facility were eventually found guilty of criminal negligence for failure to provide adequate measures to secure the machine.  

Enhancement Proposal

Despite the Goias disaster and other tragedies, it was another 30 years before the IAEA and other agencies released a proposed design modification for the radiation symbol.  

In the updated design, the trefoil is no longer the center of attention.  Instead, the trefoil radiates a source of danger and is a thing from which someone should flee.

The entire signage is cast in red and black – an improvement for sure, given the common Western interpretation of red equaling danger.  However, it’s an interesting choice for an Asian audience, given the common interpretation of red equaling good fortune.

But what's most significant here is that we’ve moved from a single symbol - the trefoil - to a multipart diagram with very primal elements at work:    

  •  strange symbol with squiggly arrows shooting out of it…
  • death...
  • run away!

In other words, we are now telling a visual story with a small infographic.  

We've traditionally been attracted to the economy and efficiency of symbols and isotypes as an expression of meaning.  For example, a single symbol has effectively expressed natural dangers such as lighting, fire, and wind.  However, as we continue to modify, concentrate or otherwise manipulate natural phenomena for our economic, political or social advantage, we increasingly expose ourselves to highly complex phenomena that has severe but often invisible effects.  Only when the effects become pronounced do we notice them, and at that point it is often too late.  

As a result, we will likely be increasingly reliant upon groups of symbols that combined to tell a story.  Individual symbols will become insufficient to convey a complex issue or threat to our health or stability.  

What’s Next?

The biohazard symbol was developed in 1966 by Charles Baldwin, an environmental-health engineer working for the Dow Chemical Company.  It’s a wonderful, unique design, whose organic-looking arcs and spiked endpoints evoke something cellular, microscopic, and perhaps dangerous. 

Much like the trefoil, the symbol has become a ubiquitous symbol for hazardous medical waste and other biological hazards.  And like the trefoil, it is highly visible and memorable. 

Charles Baldwin reflected on the design objectives:

We wanted something that was memorable but meaningless, so we could educate people as to what it means.

His word meaningless was likely in fact deliberately and carefully chosen.  Meaninglessness had a purpose: a clear slate upon which meaning could be built.  But by establishing this clean slate, Baldwin and others assumed a responsibility that they could not fulfill alone, and one that was highly dependent on sustained, future collaboration: education of anyone who came into contact with the symbol.  They had set themselves up for a daunting and unmanageable task.  The designers of the symbol created something memorable and iconic. However, without education or combination of symbols into visual storytelling, the biological hazard symbol will remain a strange, mysterious symbol to the uninformed.  

Similar to radioactive waste, biological dangers have spread from our sewage and industrial effluvia to a much more extensive presence in our supply chain and solid waste disposal.   As people less fortunate than those of us readers continue to live in and mine the dumps and trash pits an alternative source of income, they will continue to encounter quiet, invisible but deadly pathogens that will not only sicken and kill them.  And they will also hasten the spread of these pathogens to the general population of readers like you and me.  

Soon, if not already, the World Health Organization or other similar groups will be dealing with the same communication and educational burden as the IAEA.  

Hopefully they will respond with advancements in visual communications similar to the IAEA's proposal, but in a more timely fashion.  


  1. How is a drawing of a tape reel supposed to relate to radiation?

    I've never understood how the trefoil design is supposed to make sense.

    The symbol for chemical hazards looks even more like a tape reel.

    Were tape recorders considered somehow dangerous at one time? Why??

  2. The combination of red and black is fine - in good light and if one isn't colour-blind. In poor light, red and black become hard or impossible to distinguish, and only the thin white lines would be visible. Colour-blindness is fairly common, especially among men, so rather go for red and white, red and yellow or some other clearly visible contrast.

  3. Added to the above, any black-and-white photocopies of the new suggested sign would be almost entirely black. If we must go that route, at least make the white lines more visible.

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