How Long is the Short Term Workplace Exposure Limit?

Control of Substances Hazardous to Health (COSHH) is a UK law requiring employers in all industries to prevent or reduce workers’ exposure to certain hazardous substances.

The law regulates workplace exposure limits (WELs) for around 500 hazardous substances. These are legal limits of exposure, measured in concentrations of the hazardous substances in the air (usually mg.m³), averaged over a given timeframe.

COSHH legislation requires that workers are only exposed to a certain amount of a hazardous substance in a specified period of time – the time weighted average (TWA).

What is the Short Term Workplace Exposure Limit?

The short term workplace exposure limit is 15 minutes. A short term exposure limit (STEL) is the concentration to which workers can be exposed continuously to a hazardous substance before it starts to affect their health.

What is the Long Term Workplace Exposure Limit?

The long term exposure limit (LTEL) considers an eight hour reference period. COSHH law requires that the short term exposure limit must take priority over the long term exposure limit.

Short Term vs. Long Term Exposure

The long term exposure limit is there to protect workers from concentrations of harmful substances – the sort of substances which, over an extended period of time, could result in long-term chronic health conditions.

On the other hand, the short term exposure limit is concerned with peak exposure incidents. It’s there to protect workers against immediate ill health effects, whether that’s nausea, dizziness, inflammation, or more serious conditions.

In any case, employers have a legal responsibility to ensure that every employee is not exposed to any concentration of any substance that exceeds the substance’s WELs. And if you run a school, a university or a healthcare establishment, you’ll also have to consider exposure risks for your students, patients, and other visitors.

Exposure Limits in Your Workplace

Many substances will list WEL values on their packaging. However, you must not assume that a substance that does not specify a WEL is necessarily safe to use in all environments for any period of time.

Potentially, all workplaces will make use of hazardous substances with WELs. For example, it’s common to find cleaning products in schools and offices which, if used for too long in a poorly ventilated area, can lead to a range of health problems.

But hazardous substances are so widespread in some sectors that workers may risk excess exposure as a matter of course. In healthcare, for example, employers must meet COSHH exposure regulations for a huge number of substances, including isoflurane, Entonox, formaldehyde, inhalable dust, and a wide range of hazardous chemicals too numerous to mention.

Meeting Your COSHH Obligations

All workers must pay attention to the WELs for every substance they work with. At the same time, you must supply your staff with adequate PPE for each task they undertake, while maintaining an adequate air ventilation system for your workplace.

Yet even with these measures in place, your workforce may still get exposed to dangerous concentrations of hazardous substances. Faulty equipment can lead to a leak. PPE can get damaged or compromised. And a small accident can lead to a substantial chemical spill, the effects of which could last long after the spill’s been cleaned.

But we can help you fulfil your COSHH obligations wherever your staff are exposed to hazardous substances with our bespoke workplace exposure monitoring report. Our comprehensive reports include clear and actionable recommendations, so you’ll know exactly what you’ll have to do to protect your staff.

We specialise in healthcare settings, where we can employ both continuous monitoring and personal sampling processes for operating theatres, endoscopy suites, pathology laboratories, maternity wards, fracture clinics, and more.

Head here to learn more about out workplace exposure monitoring services, and find out how we can help in your department.

Penthrox vs. Entonox for Long Term Exposure

Penthrox and Entonox are both used for pain management in healthcare – particularly in trauma or emergency settings.

In this post we’ll examine the benefits and risks of each.

What is Penthrox?

Penthrox is a disposable inhaler containing a drug called methoxyflurane. When you pour this drug into the device, a gauze inside soaks it up, allowing patients to inhale the vapours. Penthrox is mostly used to offer short-term relief from trauma pain until practitioners can establish a more long-term pain management solution.

It’s also useful for providing relief during brief, painful procedures, like wound dressing.

Penthrox inhalers weigh about 100g and are approximately 15cm long. And as they’re not pressurised, they can be transported on airplanes with no issue. As such, Penthrox is a lot more portable than other pain management solutions, which is why it’s often used in ambulances.

What is Entonox?

Entonox comes in a cannister containing 50% oxygen and 50% nitrous oxide (N₂O). Inhaling this gas mixture provides effective short-term pain relief during certain investigations and procedures.

Entonox cannisters are refillable, though they’re fitted with disposable mouthpieces that must be changed between use for better infection control. They contain built-in regulators, meaning that they can be set up and applied quickly in an emergency. All you have to do is attach a hose and a valve, and it’s ready to use.

What Are The Risks of Penthrox and Entonox?

Both Penthrox and Entonox are effective at providing pain relief. Which option you choose will depend on your budget, along with certain practical considerations, such as space and portability.

However, both Penthrox and Entonox pose certain risks, particularly when it comes to long-term exposure.

The Risks of Penthrox

Some people are hypersensitive to methoxyflurane, the drug contained in Penthrox. It can also pose risks to patients with underlying hepatic conditions, and to elderly or other patients with risk factors for renal disease.

Even small doses of Penthrox can cause dizziness, headaches, sleepiness and nausea. But excessive doses can lead to renal failure.

Maximum Dose of Penthrox

The manufacturers recommend that doses should not exceed 6ml in a day or 15ml in a week. But they also claim that “the frequency at which Penthrox can be safely used is not established”. You can read the full safety information for Penthrox on the manufacturer’s website.

The Risks of Entonox

Practitioners do not administer Entonox to patients suffering from certain conditions. For example, as Entonox can cause a rise in intracranial pressure, it’s not suitable for use with patients with head injuries. Nor should it be used if the patient has any air trapped in the body, such as with blocked bowels or restricted airways.

Short Term Exposure of Entonox

In the short-term, Entonox can cause dizziness, sleepiness, nausea, and even hallucinations. But these side effects usually stop quickly once the patient stops breathing the gas mixture.

Long Term Exposure to Entonox

Long-term exposure to Entonox can affect the body’s ability to absorb vitamin B12. This can result in damage to nerves and red blood cells.

So long as the patient uses controlled doses of Entonox only when needed, there should be no risk of any long-term effects. However, Entonox can pose an occupational risk to healthcare workers. Cannisters can leak, and some of the gas mixture may escape through the patient’s mouthpiece.

Risk to Hospital Staff

Entonox is often used in maternity wards to provide pain relief during labour. There have long been concerns about midwives’ occupational exposure to Entonox, and the long-term health risks this may pose.

How to Manage Penthrox and Entonox Risks In Your Hospital

When it comes to Penthrox, the manufacturers recommend that patients self-administer using an Activated Carbon (AC) Chamber, and that they always exhale through the inhaler’s mouthpiece. Yet even with these measures in place, some methoxyflurane may still escape, posing occupational risks to practitioners.

Similarly, you can reduce the occupational risks of Entonox through carefully controlling dosages, and through advising patients on safe and effective use. Though if patients are self-administering Entonox, they’ll be doing so while in a state of acute pain and stress. So it’s almost inevitable that some potentially-harmful N₂O may leak and circulate.

Test Staff Exposure Levels

So if you want to significantly reduce the occupational risks of Penthrox and Entonox, it’s best to test your staff’s exposure levels before establishing a reliable air purification system.

We specialise in exposure monitoring for healthcare settings. Using both continuous monitoring and personal sampling techniques, we’ll produce a comprehensive workplace exposure monitoring report for any hazardous substances in your hospital, including methoxyflurane and N₂O.

Get in touch to discuss how we can help you control the occupational risks in your healthcare setting.


Long-Term Effects of Chlorine Exposure

The chemical element chlorine has been used for years in sanitation, disinfection, and antisepsis.

What is Chlorine Used For?

In the form of hypochlorous acid, chlorine is used to kill bacteria in water treatment plants and public swimming pools. Chlorine is also a major element of disinfectants and bleach, so it can be found in many domestic, commercial, and industrial cleaning products.

But chlorine has also historically been used as a weapon. It was used on the battlefields of the First World War, and more recently as a chemical weapon in Iraq and Syria.

Despite its ubiquity and its life-saving role in sanitation and disinfection, chlorine is a highly toxic gas. Short-term exposure can cause certain health hazards. Long-term exposure can be lethal.

Short-Term Effects of Chlorine Exposure

You might have noticed the short-term effects of chlorine exposure from spending a little too long in a swimming pool: Blurred vision, a burning sensation in the eyes, throat or skin, a shortness of breath, chest pains, and nausea.

If chlorine can cause this much damage in the short-term, then imagine what it can do in the long-term.

The Long-Term Effects of Chlorine Exposure

The long-term effects of chlorine exposure can include the development of chronic lung problems, including bronchitis and asthma, and even some cancers.

Even a short, single exposure to high concentrations of chlorine can cause immediate lung damage, which could be irreparable. Breathing high concentrates can also lead to a build-up of fluid in the lungs, which can result in suffocation and death.

Who’s At Risk of Long-Term Chlorine Exposure?

Anyone who works in any industry that makes use of chlorine is at risk of exposure. This might include:

  • Commercial cleaning staff, and cleaning personnel in hospitals, schools, universities, and other public buildings.
  • Anyone who works around or near a swimming pool, including health club staff, lifeguards, and professional swimmers and their coaches.
  • Sewage treatment and water purification workers.
  • Workers involved in plastics manufacturing and bleach, chemical and pharmaceutical production.

How to Manage the Risks of Long-Term Chlorine Exposure

  • Learn to spot the signs. Chlorine has a distinctive, highly unpleasant smell, so you should have no trouble detecting a leak. But you should also be able to recognise the symptoms of both short- and long-term exposure, in both yourself and your colleagues.
  • Use adequate PPE. Ensure that anybody who handles chlorine in your workplace has adequate personal protection equipment (PPE) for the task at hand. Read our guide to choosing the right PPE.
  • Follow the procedures. Abide by the COSHH guidelines when it comes to short- and long-term exposure limits. And have a thorough cleaning and containment procedure in place in the event of a leak or spillage.
  • Keep things ventilated. A good air filtration system can cycle the air in a room, removing any potentially harmful gases. This can help reduce the risks of exposure from cleaning products, for example.

Chlorine Exposure Monitoring Services

For total peace of mind that you’re doing all you can to protect your staff from exposure to chemicals, we offer workplace exposure monitoring services.

We’ll employ both continuous monitoring and personal sampling processes to help you understand the exposure risks in your workplace. We’ll then produce a comprehensive report including clear and actionable recommendations, so you’ll know exactly what to do to safeguard your staff.

Head here to learn more about our workplace exposure monitoring services, and find out how we can help you manage the risks of chlorine in your organisation.


Isoflurane – Safety, Disposal and Monitoring in Hospitals

Isoflurane is one of the World Health Organization’s Essential Medicines. However, it can cause some adverse effects in both patients and in practitioners.

This is an essential guide to isoflurane – particularly in regard to how to store it, dispose of it, and monitor it in hospitals and other care settings.

What is Isoflurane?

Isoflurane is a general inhalation anaesthetic used as a sedative agent, and as a bronchodilator for patients with acute severe asthma. It’s non-flammable, it readily vapourises, but it’s a liquid at room temperature.

Anaesthetists always administer isoflurane in conjunction with air or pure oxygen. Though isoflurane can induce anaesthesia, anaesthetists also use it to maintain a state of general anaesthesia that’s been induced by another drug.

How Dangerous is Isoflurane?

Isoflurane can also be hazardous for practitioners. In its liquid form its irritating and corrosive, so it should never come into contact with the eyes, the skin, or any mucous membranes. And if inhaled in its vapour form, isoflurane can cause headaches, dizziness, and fatigue. Prolonged exposure can lead to chronic conditions, and even renal, hepatic, and reproductive disorders.

Some have also raised safety concerns about certain general anaesthetics, such as isoflurane, in young children. Animal studies suggest that isoflurane, when used in combination with nitrous oxide and certain other anaesthetics, may increase the risk of neurodegeneration.

There are also concerns that, with elderly patients, inhaled anaesthetics may cause brain damage that accelerates the onset of Alzheimer’s disease.

Isoflurane Safety Information

You can access all isoflurane safety information – including monitoring methods, on-site screening techniques, and all known possible side-effects – on the EMC website. Head here to access the EMC isoflurane safety information.

How to Store Isoflurane

You should store isoflurane bottles in a well-ventilated area at temperatures between 15°C and 30°C. You should return isoflurane to the storage location immediately after use, ensuring the bottles are closed tightly.

How to Dispose of Isoflurane

Treat isoflurane as a hazardous chemical waste and dispose of it accordingly. Place the waste material in a tightly-sealed container with a clear label, before disposing of it along with other chemical wastes.

How to Monitor Isoflurane Levels in Hospitals

Following a large spillage, there may be residual isoflurane levels in the environment. However, even the smallest leak from your anaesthetic machine could prove hazardous in the long-term. Workplace exposure monitoring will help meet your COSHH obligations and identify if your staff or patients are being exposed to isoflurane and other hazardous substances.

If it’s properly stored, and if your anaesthetic equipment is properly maintained, then you should have few problems with isoflurane in your health setting. However, there may be a spillage. As isoflurane is highly volatile, a small spillage can dissipate almost immediately. But you’ll have to take immediate action to clean a large spillage.

You’ll need adequate training and appropriate PPE – including respirators. You’ll also have to ventilate the area while evacuating anyone who does not have access to appropriate PPE.

We offer an expert workplace exposure monitoring service that will ensure you meet your COSHH obligations wherever your staff are exposed to hazardous substances in your care setting. This can include exposure to isoflurane.

Our fully-accredited consultants will manage the work for you, eventually providing a comprehensive report that includes discussions and recommendations based on our findings.

Head here for more information about our bespoke air quality monitoring, to talk to an expert, or to get a quote.


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