Why does chemical safety represent a unique and more insidious problem than most workplace hazards?
Safety managers the world over are charged with ensuring workers are using the correct safety clothing to protect against chemicals.
But how many chemicals are in use today?
In scientific terms, a chemical is any substance consisting of matter. Everything we can see, touch and feel is a chemical. Yet in the context of health and safety by the term “chemicals” we are usually referring to those liquids and sometimes dusts that we use at home for cleaning and other purposes, and in the workplace for a variety of applications. The oil, gas and petrochemical industry is a classic case, using many chemicals, whether feed stocks and raw materials, catalysts used in different processes, finished products or those used in maintenance. In this case selection of appropriate chemical protective clothing is a challenge - especially when many chemical hazards in the workplace can legitimately be described as "The Hidden Killers"
This blog will look at why this phrase is apt for many chemicals, considering, :-
- What is the unique nature of many chemical hazards that means they represent a “perfect storm” for safety managers?
- One classic and very common example of a "hidden killer" chemical– one of thousands with similar properties
- The implications.... why a common misunderstanding of a widely used CE standard chemical test is so dangerous
Chemical Safety... a Global Challenge
Estimates for the number of chemicals in use throughout the world vary widely – with 84,000 or more being commonly quoted. This is however probably an over-estimate. In 2016 the US Environmental Protection Agency listed 38,304 chemicals of which 8,707 were actually in use. So it is certainly numbered in thousands.
On individual chemical plants the number can vary depending on what the plant does - from a handful to several hundred. I have certainly visited chemical plants where any of four or five hundred chemicals could be present at any one time.
Whatever the exact numbers are, chemicals are a fact of our industrial lives, and many present hazards for workers. Yet hazards that are unique and somewhat different from most workplace hazards. So what makes chemicals so special?
Health & Safety at Work: “If a brick falls on your head, you will know about it”
Most hazards in the workplace are obvious. A danger on a building site is that of falling bricks. Most of us can easily anticipate without too much training what will happen if one falls on our head. So guarding against that hazard by wearing suitable PPE (a hard hat), just in case is clearly sensible.
Furthermore, if that hazard does become a reality and the brick really does fall on your head, it is immediately apparent. You will know about it. Wearing a hard hat or not it is very unlikely that you would carry on and not notice.
Most workplace hazards are of this nature; falling from height, tripping over an errant cable or being engulfed by flame from a burst pressurised valve. The consequences are immediate and relatively obvious.
Some chemicals of course behave in a similar fashion. Acids are the classic case – if an acid splashes onto your skin the resulting burns will be obvious and immediate. However, the hazards presented by many chemicals are different and far more insidious. In these cases you might not even notice if it contacts your skin… and yet the consequences of that contact, whilst not immediate, may well be devastating.
Example: The Health Effects of Benzene
Take, for example benzene (CAS No 71-43-2). A very common chemical – an aromatic hydrocarbon – derived from oil and used in processes to make several other commonly used chemicals as well as an additive in petrol (though as a consequence of concerns about its health effects this is less common than it used to be and levels are strictly controlled). Most of us however, will regularly come into contact with very low levels of benzene.
Benzene is not selective about how it enters the body. It can be inhaled, ingested or will readily absorb through the skin. It is a carcinogen and exposure can increase the likelihood of developing cancers and other diseases.
These diseases include aplastic anemia, acute leukemia, bone marrow abnormalities, cardiovascular disease, acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), acute lymphoblastic leukemia (ALL), and chronic myeloid leukemia.
The Health effects of Benzene in Children
A study in 2013 of the health effects of benzene exposure in children after a flare up at a refinery in Texas suggested that:
Surprisingly perhaps, knowledge about the adverse health effects of benzene is not new. In fact in 1928, almost one hundred years ago, the first case of leukaemia associated with benzene exposure was reported. And later in 1948 the American Petroleum Institute (API) stated that:-
“it is generally considered that the only absolutely safe concentration for benzene is zero. There is no safe exposure level; even tiny amounts can cause harm” 
In fact even the Nazis were fully aware of its dangerous nature… they used its injection as a murder weapon…
Despite all this - and other examples of the early recognition of the dangers of benzene the first regulations to control the use of benzene were finally introduced by OSHA in 1978... some fifty years after the first related case was reported.
The point is, benzene is a perfect example of a very common chemical (it does actually occur naturally in some situations) that has limited immediate effects – skin contact may result only in irritation – but has potentially devastating long term consequences which could certainly involve life-changing illnesses and possibly death. And benzene is far from unique; there are thousands of chemicals that work in a similar way. A chemical can be a silent, devious and insidious killer, making them even more difficult to protect against than most workplace hazards.
How much is really known about chemical hazards in the workplace?
Yet there is another reason why chemicals represent such an acute problem for safety managers keen to ensure proper chemical safety for workers. A reason highlighted by a quick perusal of the chemical safety data sheets of a random selection of chemicals.
In the hazards section of these useful documents (a good source is the European Chemicals Agency ECHA) you will often find statements such as “suspected of causing cancer” or “may cause damage to the unborn child” (my italics). The fact is knowledge of the health effects of many chemicals is limited and uncertain.
How do we know what the health consequences of chemicals are?
To be certain of the health consequences is itself problematic; it requires extensive and long term testing and analysis. It needs a sufficiently large sample of people exposed to a chemical (which realistically and ethically cannot be done deliberately) along with a control sample of a similar number of people known to not be exposed, followed by long term monitoring and testing. Understandably this is not easy to do and where such analysis exists it is normally conducted amongst historically exposed groups.
So, given the thousands of chemicals in use it is quite likely that there are health effects of chemicals that are not yet recognised and potentially some chemicals for which the health effects have simply not yet emerged and for the time being remain unknown...
At the same time the history of industry is replete with examples of chemicals that were assumed at first to be the next wonder material… and yet later proved, through the suffering and sometimes death of those involved… to have devastating health consequences. And the example of benzene above shows that whilst things have undoubtedly improved, the law is not good at responding rapidly to evidence of a problem and introducing regulations to control use.
Overall, many chemicals represent a unique hazard in the workplace; a specific combination of properties that from the point of view of safety and protection is almost a perfect storm.
Chemicals are a hazard that can be invisible at the time, may only take effect years later and that may not yet even be known. The obvious conclusion for the safety manager charged with ensuring his workers are safe – especially in large plants where hundreds of chemicals might be in use – is that chemicals and how to protect against them must be properly understood and that wide safety margins must be built into the safety clothing selection process. It is easy to guard against the possibility that a brick might fall on someone’s head. It much more of a challenge to guard against the health effects of contact with chemicals that not only might not be noticed, but the consequences of which may not take effect for years or even decades, and which you might not even be aware of!
The Biggest Misunderstanding in Health and Safety at Work?
This is why the current and almost ubiquitous misunderstanding of the chemical breakthrough time in a permeation test against safety clothing fabric is such a potential problem. The fact is, most safety managers, when selecting chemical protective clothing primarily use a breakthrough time from a permeation test as an indication that the suit is safe to use. Unfortunately in most cases this test is misunderstood with the result that users may think they are protected from the chemical when in fact they are not.
You can find out more about this common misunderstanding of permeation test results in our blog "Permeation Test breakthrough is not what you think it is"
Or you can discover more about how to select the most appropriate chemical suit for your application by downloading a free copy of “The Guide to Chemical Suit Selection" from the link below.
 “Journal of Pediatric Hematology and Oncology”:https://www.tandfonline.com/doi/abs/10.3109/08880018.2013.831511