Like other technologies that have become indispensable—mobile electronic devices and X-ray imaging among them—the practical application of UV technology is not totally void of exposure risks. But in an increasingly dangerous world, the need for and efficacy of these tools far outweighs their potential hazards. And with common sense precautions, the exposure to latent threats can effectively be mitigated.
UV technology allows us to see a huge array of phenomena not perceptible to the naked eye. It unlocks access to and management of potentially dangerous issues that were previously hidden and only known when they reached worsened conditions, or after time consuming, inefficient and often unreliable traditional inspection techniques.
In the case of infrastructure, ultraviolet light technology has massive implications with nondestructive testing applications.
The D+ to B in NDT:
Every four years, the American Society of Civil Engineers’ (ASE) Report Card for America’s Infrastructure assigns letter grades based on the physical condition of and needed investments to improve the nation’s infrastructure systems. In 2013, America’s GPA rose to a still disconcerting D+ with a recommendation that $3.6 TRILLION be invested by 2020 in order to, “maintain a state of good repair. [sic] That is, approximately what amount of investment is needed to get to a grade of B.” (Engineers, n.d.)
The need for proper maintenance of and investment in infrastructure is not just an issue of national pride. Catastrophic failures within any of these systems can—and is too many instances actually have—caused numerous casualties, massive property damage and resulted in crippling liabilities for the municipalities and the private companies who construct and maintain them.
A U.S. Department of Justice Report found that plaintiffs won nearly a third of all product liability lawsuits. Of successful civil suits, a third of those plaintiffs were awarded punitive damages on top of compensatory damages. Specifically, punitive damages were reserved in part for, “civil claims in which the defendant’s conduct was considered grossly negligent”.
- 13% of cases with punitive awards had damages of $1 million or more.Just last July (2015), British Petroleum finally ended litigation stemming from the Deep Water Horizon oil spill by agreeing to pay about $18.7 billion in damages for water pollution caused by the spill, settling claims with the U.S. government and Louisiana, Mississippi, Alabama, Texas and Florida.Regular inspection schedules utilizing Nondestructive (NDT) testing kits offer far reaching, huge cost savings because of their ability to detect defects onsite and in real time for pennies on the dollar.
Risks: Macro vs. Micro
Understanding the risks that nondestructive testing can mitigate on the macro level provides a framework for getting a better handle on safely working with the technology.
When most people think of ultraviolet light they also of think of radiation. The term “radiation” is defined as the “emission or transmission of energy in the form of waves or particles.” Light, radio waves, wireless signals and countless other natural and man-made energy sources fall along the electromagnetic spectrum (pictured) and constitute some form of radiation, each with its own uses and potential hazards.
Lower-energy waves are generally the most harmless and are used for radio and television transmissions, while higher energy x-rays and gamma rays pose the greatest safety risks–such high-energy radiation is associated with the fears many people associate with all radiation. Infrared radiation, commonly known as heat, is the most prevalent component in sunlight, followed by visible light, and then ultraviolet light.
The UV-A (365 nm) wavelength used in NDT applications falls just above the upper limit of what the human eye can detect, and when shone on a suitably reflective material can reflect back visible light, making UV-A quite useful in seeing what the eye alone cannot.
This questionnaire is actually a trick question.
Because the safety protocols associated with using UV technology are very similar to those issued for a being outside in the sun for prolonged periods.
Simply stepping outdoors leads to some exposure to UV-A radiation, and just as sunscreen is advised for a trip to the beach or other strong exposure to sunlight, occupational exposure to ultraviolet light sources warrants simple and common sense safety precautions.
Excessive exposure to UV-A radiation can potentially lead to skin cancer, so when performing NDT inspections on a regular basis, measures to shield the skin from reflected UV light are also prudent, most notably wearing long sleeves and covering as much of the skin as possible when working with the UV lamp. Sunscreen can also be used for the face and other parts of the body difficult to shield with clothing, though it’s important to select one designed to block UV-A rays to optimize occupational safety.
In NDT applications, the most significant risk factor associated with exposure to UV-A radiation is to the eyes, as prolonged, unprotected exposure is associated with cataracts. Not looking directly into a UV light source is one important precaution, though of greater concern for occupational exposure is reflected UV light.Even if you never look directly into the bulb, without eye protection, reflected UV light will pass through the eye where it can possibly cause harm.
There is no formal occupational exposure limit for UV-A radiation, though guidelines set by the American Conference of Governmental Industrial Hygienists (ACGIH) are generally used as informal exposure limits. The guidelines are for UNPROTECTED exposure and quite scientific, and with proper eye and skin protection shouldn’t come into play. The use of UV-absorbing glasses, often provided with NDT inspection lamps, prevents these reflected rays from reaching the sensitive tissue of the eyes, and is the most important safety precaution to take into consideration when working with UV lamps.
As the risk of damage to the eyes can begin with exposure as short as 16 minutes, possibly less in the case of a high-intensity source, this highlights the need for eye protection during occupational use of UV-A inspection lamps. The use of proper protective eyewear, combined with the right clothing and sunscreen (where applicable) renders UV-A fully safe for routine inspection, allowing the power of UV technology to be freely and safely used in a diverse range of NDT applications.
Even the safest of tools and technologies have protocols recommended for their operation. Risk assessment is something we do consciously and sometimes without even realizing it. Getting all the facts and taking prudent precautions based upon them is the best way to reduce your exposure to any of the potential hazards you encounter. When it comes to the use of UV nondestructive testing technology, the benefits to society and the bottom line far out-weigh the small risks that can successfully be ameliorated when you know what they are and take the proper precautions.