“There are things known and there are things unknown, and in between are the doors of perception.”  Aldous Huxley

We’ve all seen them; factories are scattered across the landscapes of America.  There’s probably one in or near the town where you live, where you work, where you raise your children.  I live near one and pass three more on my morning commute.  The proximity of these facilities to our everyday lives often raises questions and concerns in regards to the facility’s processes, the byproducts of those processes, and how they affect the health and safety of the general public.  However, these concerns are often based on perceptions from a bygone era and misinformation.  The factories of today, while similar in appearance, are safer than their predecessors.

What are you looking at, really?

When you look at a factory, what are the first things you notice? Many individuals share a predetermined belief that facilities, like the one pictured above, are hazardous by their very existence.  While they look old, dilapidated, or dangerous, is their appearance affecting their function and their processes?  Most of the time, the answer is no – the process, regardless of the exterior appearance of the facility, may still be running as efficiently and safely as it was at its’ commencement. The rust you see on that tank?  It’s probably not affecting the interior contents.  The smells, the noises, and smoke clouds?  With some exceptions, they are harmless.  What you think you see isn’t always what you get.  So, what are people so afraid of?

Is a rusted tank still safe?

I can’t speak for everyone, but as a child I came to associate rust with age and decay.  I grew up in the country and we had cattle, so we had a barn.  As I aged, so did the corrugated walls of the barn.  Eventually, you could brush the rust off the wall with a swipe of your hand – and you could see through the metal where the rust had done its best work.  By the time I left home, the barn had become so decrepit and unstable that a summer thunderstorm demolished a piece of my childhood scenery with one gust of wind.  Thus, my association of rust to age and decay was born, and it’s one I created through my own personal experience.

If you’ve seen factories, or even photographs of them, you know that tanks are a common feature of a facility’s silhouette.  You probably also noticed that those giant tanks, holding who knows what, are a little rusted.  Does that mean they are structurally weak, like the barn was?  Does that mean they are a danger to those in their vicinity?  Probably not.

Steel is the most common construction material for both pressure vessels and storage tanks, the latter being what you see most often as you drive by a factory. Steel rusts when it comes into contact with water and oxygen, so, when a storage vessel is placed outside, the ingredients for rust are immediately available and rust is inevitable.  So, while its’ physical appearance may be a bit dismaying, it is usually structurally sound.

Tanks are built to withstand the elements.  They vary in thickness, depending on demand. Some are double-walled, and some have insulation, so while they may appear rusty on the outer shell, the interior is intact. In addition to these built-in protections, periodic thickness and strength testing is conducted to ensure the integrity of the tanks.  The bottom line is, thanks to tank manufacturers and safety professionals, tanks will be replaced before they become a hazard and a little rust is nothing to lose sleep over.

What’s coming out of the smokestacks?

Had I been asked this question twenty-five years ago, my answer would have been clouds.  Sometimes the clouds were black, sometimes they were white, but I was convinced that smokestacks were the source of all the clouds in the sky.  As I matured and childhood innocence gave way to worldly ideas, I came to view smokestacks as a source of pollution.

Smokestacks, which made their first appearances during the 17th century, were originally used to increase the flow of air into a furnace, not to disperse pollutants.  However, even though scattering pollutants was not the intent, byproducts of the combustion processes performed in the factories are dangerous.  These dangers, and their observed consequences, prompted Congress to pass the Clean Air Act in 1970, which required the EPA to stipulate standards for levels of sulfur oxides and other damaging emissions.  It also established deadlines for clean-up and required new plants to adopt modern abatement technologies.  Then, in an amendment passed in 1977, it forbade the use of tall stacks as an alternative to emission controls.  For more than 40 years, the Clean Air Act has shown steady progress in air pollution reduction.  A 2011 EPA study found that reductions in fine particle pollution and ozone pollution achieved by the Clean Air Act amendments of 1990 aided in the reduction of premature deaths, heart attacks, and respiratory problems.

The Clean Air Act mediates hazardous emissions, but sometimes the billowing clouds pouring from smoke stacks are only water vapor.  They look ominous, but they are harmless.  When fossil fuels are burned, water vapor is created by the combustion of hydrogen in the fuel with atmospheric oxygen.  So, the smoke you see is this water vapor forming a cloud as it contacts cool air – while it may contain traces of other chemicals, it’s really just H2O.

As long as we have combustion processes, we will have byproducts.  However, technology, innovation, and regulations have significantly improved the air we are breathing.

Okay, but what’s that smell? Is it dangerous?

I work in St. Louis, Missouri.  I don’t know how much you know about St. Louis, but we are home to, and famous for, Anheuser-Busch Brewery.  You’ve probably seen our Clydesdales; they’re beautiful brand ambassadors and we’re pretty proud of them.  What we take less pride in, however, is the smell that occasionally wafts about the busy area the brewery is located in.  If you ask a St. Louis native, they might tell you it smells like home, or they might not notice it at all anymore.  On the other hand, a visitor from out of town may find the smell of fermenting beer to be significantly less pleasant.  Regardless of opinion, it isn’t hazardous.  Nonetheless, different factories are running different processes and produce different smells.  So, what about the rest of them?

What causes an odor?  The answer varies from process to process.  For instance, the odor you may encounter near a paper mill comes from kraft pulping.  Kraft pulping uses heat and chemicals to pulp wood chips for making paper.  The reaction produces gaseous sulfur compounds, which smell like rotten eggs. While sulfur compounds are dangerous, the concentration at which the odor of sulfur compounds is annoying is far lower than the concentration at which it is dangerous.  Other processes such as the production of semi-conductors, pharmaceuticals, and textiles can produce an ammonia odor.  Coal-fired power plants may smell like formaldehyde. The list goes on and on. These are all dangerous compounds, but again the concentration at which the odor is annoying is far lower than the concentration that is dangerous.

In general, most substances that cause odors in the outdoor air are not at levels that are dangerous to your health.  This is not to say that some individuals who are more sensitive to aromas will not suffer repercussions of prolonged exposure to non-toxic odors.  Some common symptoms are watery eyes, cough, or headaches.  Typically, odors are kept at non-threatening levels via odor control laws and ordinances, and odor control technologies.  There are some notable exceptions, of course, in cases of spills and releases, but these are not typical.  So, while the smell may not be pleasant, it’s usually harmless.

They aren’t all bad

By themselves, concerns like rust, smokestacks, and odors shouldn’t keep you awake at night.

That said, it is not unreasonable to notice rust, smokestack, and odors.  Rust stains on a factory may not be a sign of eminent danger, but they might be a sign of neglect.  If a factory can’t take care of something obvious like rust, might they may be missing something more important but less obvious.  Likewise, odors from a factory may just be annoying, but are they an early warning of something worse.  Those billowing clouds?  If they are white, it is probably reasonable to assume that it’s just water.  But if the smoke is yellow, or green, or black, that’s never okay.

Worry about the right things

Factories have a rich history in the United States and it’s no question why they established a bad reputation in the years of, and immediately following, the Industrial Revolution.  And while there are plenty of reasons to be vigilant, take a moment to be sure your concerns are well directed.  In other words, it’s okay to worry, but worry about the right things.  Industry is constantly changing, evolving, and growing.  In addition, there are people, like those of us working in process safety, whose job it is to keep you safe.  Maybe you are seeing a hazard that needs to be addressed, but maybe what you think you’re seeing isn’t what you’re seeing at all.