Occupational Hygiene

Check Your Hygiene: Still using a Confined Space Monitor for Diesel Emissions?

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Check Your Hygiene

Picture this: Workers are using a diesel generator in a basement car park or an excavator working inside a building. You can see and smell diesel exhaust fumes in the area, and when you ask what is being done to protect workers from diesel emissions…someone points to the confined space gas detector…and in my head I scream, “nooooooo…”.  This happens more often than you think. But why is a confined space gas monitor not enough?

Well confined space gas detectors typically measure oxygen, carbon monoxide, hydrogen sulphide, and the lower explosive limit…all very important, but there are a few other diesel exhaust gases that can cause you problems. The most common ones we see are the oxides of nitrogen such as nitric oxide (NO) or the more toxic nitrogen dioxide (NO2) …and then there is the carcinogenic diesel particulate matter (DPM) that you have to worry about too.

So What Should be Done? The key with all of this is to follow the hierarchy of controls (which is the technical term for not using PPE first).

You want to make sure that you ventilate the area well – which doesn’t just mean putting fans in the building. You need to get rid of the contaminated air, and replace it with clean air. You should consider reducing the amount of time the equipment is idling…so turn it off when not in use – or if it’s a generator – put it outside the car park and run the power leads to where you need them to prevent having an issue in the first place!

You should use a calibrated confined space gas detector (key word: calibrated!!) and a calibrated gas detector to measure oxides of nitrogen in real time.  Both of these should be set to raise an audible alarm whenever they reach certain trigger points (I would recommend that being at or below the Workplace Exposure Standard) so that workers leave the area if an alarm is raised.

Monitoring for chemicals in real-time using gas detectors is a common task for any occupational hygienist. There are many advantages to using them, but you have to know how to use them correctly, be sure you are monitoring for the right things, and know their limitations. Sometimes you can use wireless gas detectors if you want to get fancy and your work will occur over a long period of time, or over many locations, which is where these can be helpful…but gas detectors alone aren’t enough.

There are a number of additional things you need to consider to prevent exposure to DPM such as using low emission engines, low emission fuel, proper engine maintenance, filtered operator’s cabins, and PPE…and wherever there is a risk of exposure, you should provide training to your workers in the health effects of the chemicals (eg: the different gases/DPM) that they might be exposed to.

So it’s not really that simple (hence my “noooooo” scream before), which is maybe why it’s still common to see these issues in the construction industry?

Where can I go for help? You should ask your friendly Occupational Hygienist!

(Disclaimer: I haven’t listed all controls to prevent exposure – or even all gases or hazards that come from diesel exhaust…this is just a quick overview….do not rely on this alone….call an Occupational Hygienist!!)

Check Your Hygiene: Heat Stress

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Check Your Hygiene

What? Heat Stress is the impact a worker feels from doing their work – including environmental factors (temperature, humidity, radiant heat etc) and clothing requirements.

What can happen? Work involving hot temperatures can lead to workers feeling physical discomfort through to conditions that are life threatening. These can include muscle cramps and dizziness, heat rash, dehydration, fainting, increased heart and breathing rate, weakness and lack of energy, poor performance / increased response time, and becoming moody and short tempered (I admit sometimes it’s difficult to tell the difference if you already have moody and short tempered people!!). If untreated, this can lead to more the more serious stage of ‘heat stroke’, which occurs when the body’s temperature rises above 39oC. Heat stroke is a medical emergency and can result in death.

Are some people at a higher risk of developing a heat-induced illness? Yes! These include workers who are physically unfit, overweight or obese, the elderly, and those with heart conditions. People who are not ‘acclimatised’ to the work environment, or are not adequately hydrated (ie: haven’t had enough water) also stand at a higher risk. Some medications can also affect the ability of workers to maintain their core body temperature.

What can I do to reduce the risk of heat-related illnesses? Quite a lot actually! Why not try to get rid of the source of heat such as shielding of radiant sources if that’s applicable. You can increase the airflow to the working area, you can use air conditioning, maybe think about starting work early in the cooler part of the day and use naturally shaded areas. Cut down on the amount of coffee you drink, and stay clear of energy drinks and alcohol the night before. You could also consider work-rest regimes and rotating with co-workers so the work load is shared.

One of the most important aspects of preventing heat stress is to make sure that you are aware of the signs and symptoms and know how to control it – so stay hydrated (ie: drink plenty of water) and work at a self-paced level – don’t overdo it!

Where can I go for more information? Ask your friendly Occupational Hygienist!

Check Your Hygiene: It’s Ubiquitous

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Check Your Hygiene

What? Ubiquitous means that it’s everywhere. A bit like pasta at my house…or mashed potato on my pasta off-days.

Why not just say, “it’s everywhere”? It sounds far more scientific to say, “ubiquitous”

How often are you really using this word? Surprisingly, there are lots of cancer-causing agents that are ubiquitous. Things like some PAHs, Bispheol A (BPA) and even outdoor air pollution. There are a few chemicals that Occupational Hygienists will monitor for, that are also ubiquitous. So in fact, I use this word quite a lot.

Why is this important? Well when scientists are trying to determine whether certain substances cause cancer, their results can be confounded by the presence of other chemicals that also cause cancer. When these chemicals are ubiquitous, it makes it tricky. It’s also important to know that if you go out to monitor for these chemicals somewhere in the environment to see if something is causing an issue (eg: a new coal-fired plant), that those chemicals you are monitoring for might have been there all the time in the ‘background’ as they are ‘ubiquitous’.

It’s also my all-time favourite word to drop into a technical discussion.

Who is the best person to ask to help with ubiquitous chemicals? Ask your friendly Occupational Hygienist!

Check Your Hygiene: Ototoxins

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Check Your Hygiene

Did you know that some chemicals can cause Hearing Loss? Exposure to a number of common industrial chemicals and some medications can cause hearing loss or make the effect of noise on hearing worse. These are called ototoxic substances.

How is that possible? Ototoxic substances absorbed into the bloodstream may damage the cochlea in the inner ear and/or the auditory pathways to the brain, leading to hearing loss and tinnitus. Hearing loss is more likely if exposure is to a combination of substances or a combination of the substance and noise.

What are some common ototoxins? Lead, carbon monoxide, ethanol, white spirits, trichloroethylene are just a few. These chemicals are commonly found in painting, printing, boat building, furniture making, manufacturing, leather and petroleum industries.

Where can I go for more info?

 Glad you asked. There are some great resources here and here as a start.

Who is the best person to ask to help me? Ask your friendly Occupational Hygienist!