Risk Management Measures in the real world

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At the end of October, I travelled over to Helsinki for a few days. I’d been invited to deliver a short course on “Risk management measures in a REACH context”  to personnel working for the European Chemicals Agency* (ECHA) who are responsible for evaluating the dossiers chemical manufacturers have to submit under the European REACH Regulation. Over 30 people attended the course, a much bigger number than I’d normally prefer. However, they were a really nice group of people who were keen to listen and contribute to the discussion making it an enjoyable experience for me, and, I hope, for the attendees. It was good to have the opportunity to put forward my perspective on how effective risks from hazardous substances are controlled in practice in the “real world of industry.

The principle objective of REACH is to protect human health and environment from chemical hazards, ensuring that risks from the use of chemicals are properly controlled. To achieve this, manufacturers have to undertake risk assessments for all “exposure scenarios” where their products are used and produce “extended safety data sheets” for substances, which must include appropriate “risk management measures”. We’re now starting to see these new style data sheets coming through to users.

During the training session, we looked at how exposures to chemicals vary and the practicalities of obtaining adequate data for the risk assessment process. However, the main discussion centred on the realities of how “risk management measures” are implemented in industry, based on my experiences helping companies to control the risks from using hazardous substances.

I think that there is a widespread impression that controls are much more effective than they are in practice. There are lots of reasons for this, which I’ve discussed in some previous posts. Problems can occur during all the key steps involved in the design and implementation of controls – see my Slideshare presentation and this post for some examples.

It’s a particular problem with local exhaust ventilation systems. In my experience they are rarely well designed and, in practice,  their influence on exposure is considerably less than the users (and designers/suppliers) believe. The “lower tier” exposure models commonly used to prepare the REACH risk assessments can assume that LEV is up to 90% effective. The system would have to be well designed and properly used and maintained for this to be the case and I think that it is rare for it to be achieved in practice. Consequently, exposure modelling with lower tier models can considerably overestimate the reduction in exposure achieved by LEV.

Manufacturers and importers of chemicals need to make judgements about the effectiveness of controls when carrying out their risk assessments and also when deciding on what risk management measures are needed. The danger of overestimating how good they are could compromise their risk assessments and result in risk management measures being specified that won’t adequately control exposure. It’s important, then, to have a realistic appreciation of the “real world” effectiveness of common controls.

Those extended data sheets I’ve seen so far seem to specify realistic controls for the exposure scenarios. However, they are phrased in very general terms. Again this is likely to be a particular problem with LEV. For many industrial organisers “LEV” means a captor hood – often the flexible “swinging arm” type. As I’ve discussed in a previous post, these are largely ineffective at controlling contaminants. But in many cases if a company follows a general recommendation to install LEV, this is what they’ll buy.  I think that if REACH is really to achieve it’s objective of improving control, then we need to ensure that the advice on risk management measures is as specific as practicable. So with LEV enough details needs to be provided to make sure that the design of the extraction hood is appropriate.

Milling polyurethane blocks at semi automated machine
Inappropriate application of a captor hood

Another problem I’ve noticed with the new style safety data sheets I’ve seen is that where personal protective equipment is recommended the advise is too general. For example, recommending “wear suitable gloves”. This really isn’t any improvement on the older style sheets. Downstream users need more specific advice on what type of gloves are needed, particularly what they should be made of. The reality is that most users don’t have the expertise to select “suitable gloves” and in most cases the gloves used are made of an inappropriate material and are not used and managed properly.  This point is also relevant to other types of personal protective equipment. Again, I’d like to see more specific details provided.

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For me a good model for user friendly control advice is the COSHH Essentials control sheets. These provide good, concise advice on control for common processes on a maximum of 2 sides of A4. Where LEV is recommended specific details on the hood design, including an outline diagram, is provided. These sheets aren’t perfect – their advice on personal protection is too vague, for example – but I think that overall they strike the right balance between brevity and the usefulness of the information.

A lot of work has to go into carrying out the risk assessments. It’s important that the output – i.e. the information on risk management measures – should be detailed enough to ensure that controls are properly designed and implemented. Unless this happens there’s a real danger that all the effort will be in vain and an opportunity to substantially improve control of hazardous substances at work will have been missed.

*ECHA’s role is to manage and coordinate the registration, evaluation, authorisation and restriction processes and to ensure consistency in the management of chemicals across the European Union.

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Reconsidering the “hierarchy of control”– Part 1

We normally take a break from running courses over the summer – most people are more interested in enjoying some time off than attending an intensive week of study. But it was back to business as usual last week delivering the BOHS module M103 “Control of hazardous substances” in Chester. I’ll also be running the international version (the OHTA course W505) over in Ireland in a couple of weeks.

One of the key concepts we cover early in the course is the “hierarchy of control” – a tool used by occupational hygienists and other health and safety professionals to assist with the selection of control measures. It’s fairly obvious that some measures are preferable to others and the hierarchy formalises this idea by providing a structured list of common options in order of preference. The concept has been around since the 1930’s. It appears to have been developed by the industrial hygiene community in the USA and then was adapted for broader health and safety risks.

The underlying principle of the hierarchy is that the best way to achieve control is by addressing the source of the contaminants. If this cannot be achieved or does not resolve the problem then an attempt should be made to control along the transmission path. Only if neither of these can be achieved should the primary control measures be based around the workers themselves.

 

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Another approach is to classify the measures by type as follows (in order of preference)

  • Prevention
  • Engineering Controls
  • Procedural / Organisational Controls
  • Worker Based Controls

 

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Whichever approach is adopted, the same order of priority tends to result when specific measures belonging to the different categories are considered.

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The hierarchy is a useful tool, but it must be remembered that in most cases more than one measure will need to be implemented, because

  • exposure can occur via more than one route of exposure (e.g. when workers are using a solvent based product exposure may occur by inhalation of vapours and via skin contact),
  • there are a number of different sources of exposure that need to be controlled,
  • there is a residual risk as, in most cases, an individual measure will not be 100% effective at controlling the contaminants.

The latter point is particularly important.

The best way to use the hierarchy is to start at the top of the list, considering each option in turn and deciding whether it is "reasonably practicable". Once a measure is selected, consideration should be given to whether the residual risk is acceptable. If not further measures will be needed. The process should  be repeated until it is likely that the residual risk is reduced to an acceptable level.

For example, a worker spraying a two pack polyurethane paints in a car body shop can be exposed to isocyanates and solvent vapours by inhalation and is likely to have some skin contact with the paint and solvents.

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In the real world it’s unlikely that elimination of the isocyanates by substituting a less hazardous paint would be feasible. Similarly process automation and containment are unlikely to be practicable. So the first measure from the hierarchy likely to be implemented is local exhaust ventilation, normally in the form of a walk-in booth. This would probably be adequate to control the exposure of his colleagues, but as he has to be inside the booth he will still be exposed to high concentrations of contaminants. Consequently there is a significant residual risk, so other controls are needed. The sprayer would need to wear suitable air supplied respiratory protection and good working methods and safe working procedures would also be needed. Personal protective equipment and good working methods would also be needed to minimise skin contact. So a “suite” of control measures is needed to adequately control the risks.

Once the appropriate controls have been selected, other measures will be needed to ensure they continue to be effective. I’ll return to this in another post in the near future.

BOHS North West meeting on Managing Chemicals

Companies that manufacture, sell and use chemicals are currently facing new challenges presented by the requirements on the management of chemicals in the workplace introduced by the REACH and CLP (Classification, Labelling and Packaging) Regulations.

It’s important for anyone involved with the use of chemicals to make sure they’re aware of the legislation and how to implement it. There are requirements, particularly in REACH, that are new and only experience will tell us how they can be implemented effectively.

The North West and North Wales region of BOHS has organised a meeting on  REACH and CLP that  will focus on the experiences of occupational hygienists who have been involved in implementing the legislation, bringing out the lessons learned.

It takes place at the Vauxhall Sports and Social Club,Rivacre Road, Ellesmere Port on Wednesday, September 14, 2011 starting at 1 p.m., with registration and a buffet lunch from 12 noon

The speakers are:

Dr Dale Iddon, HSE Consultant, Global HSE, Eli Lilly and Company Limited

‘CLP Implementation – Activities & Challenges’

The CLP Regulations have introduced major changes for the suppliers of hazardous substances and preparations, including new classifications scheme, changes to the familiar hazard symbols and the replacement of R and S phrases by hazard and precautionary statements. Dale’s presentation will concentrate on her practical experience of the activities and challenges associated with implementing CLP on a Global/Pan-European basis in a multinational pharmaceutical company.

 

Alex Wilson, Manager REACH and Chemicals Policy, Tata Steel Europe

Experience with REACH Implementation – A “downstream user’s” perspective

Alex will talk about his role as an occupational hygienist with responsibility for Chemicals policy and implementation of REACH in a multinational manufacturing company. Particular emphasis will be given to the challenges facing “downstream users” and how occupational hygienists have been involved in implementing REACH in his organisation.

 

Tracey Boyle, Workplace Environment Solutions

“Developing exposure scenarios for REACH”

In her work as a consultant assisting clients with the implementation of REACH, Tracey has been involved in preparing exposure scenarios and recommending risk management measures for clients. In her presentation, Tracey will talk about her experiences, illustrating them with case studies. She will cover collection of process descriptions and exposure monitoring (including the use of questionnaires), modelling exposure (Ecetoc, MEASE and ART), generic exposure scenarios and risk characterisation.

Book your place online here.

Listing ingredients on safety data sheets

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I received the following query from a client recently:

“At what point does a chemical have to be named as an ingredient on a safety data sheet (SDS)?”

It’s a simple question but it requires a complicated answer!!

Users of substances and products that are mixtures of several different substances need to know what they contain if they are to make a proper assessment of the risks and decide on what control measures need to be implemented. However, suppliers are often reluctant to disclose the exact make up of mixtures for commercial reasons. They don’t want their competitors (and sometimes their customers) to know the composition of their products. In some cases they may be reluctant to declare the presence of a hazardous minor ingredient as they are concerned that customers may be put off from purchasing the material.

A few years ago I had a case where a supplier did not disclose the presence of an isocyanate pre-polymer in the hardener component of a two-pack a polyurethane paint because they did not consider it to be hazardous. Pre-polymers still have active isocyanate groups and exposure to them could lead to respiratory sensitisation and asthma in some individuals. Their argument, when I spoke to them on the telephone, was that the pre-polymer wasn’t volatile and so vapours wouldn’t be given off. That may have been true, but this paint was being sprayed and workers could inhale mist containing unreacted isocyanate, which would have been a significant health risk. The users needed to know that the isocyanates were present in the paint as this would be a major consideration when deciding on appropriate control measures.

Until recently the provision of information to users on labels and SDSs were both covered by the Chemicals (Hazard Information and Packaging for Supply) Regulations (CHIP) . Recent changes in the legislative framework in Europe means that labelling is subject to the Classification Labelling and Packaging (CLP) Regulation, which is being implemented in the UK by CHIP 2009*, while the requirements for Safety Data Sheets are set out in REACH*. These Regulations are complex and can be difficult to interpret and different suppliers may take different approaches to what they will disclose.

In essence the more toxic the substance, the more likely that it’s presence will be declared at a low level on the SDS. However, the information provided does depend on the supplier, as REACH does not require them to declare all the ingredients in a mixture.

With mixtures containing “dangerous substances” (as defined by the CLP Regulations), suppliers are expected to list substances classified as such, together with their concentration or concentration range in the mixture.  The “trigger” concentration normally depending on the criteria in the CLP Regulations used to determine whether a substance is classified for a particular hazard. So, for example, a carcinogen should be declared if it is present at a concentration greater than 0.1% by weight. The mixture would have to be classified as a carcinogen under CLP if this amount was present and users would need to know why the product had been classified as such.  However, with an irritant, it is possible that it may only be declared if the concentration is greater than 1% or 5%.

At the end of the day, what goes on a data sheet depends on the supplier. In my experience there are very few that are good quality. I don’t expect that to change with the new legislation as its very difficult for Regulators to enforce the requirements in practice.

 

* CLP is being phased in gradually. For further details see my previous post here

** The Registration, Evaluation, Authorisation and Restriction of Chemicals

Monitoring skin exposure to chemicals

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Inhalation is normally considered to be the main route by which chemicals can enter the body. Most industrial processes where chemicals are used will create airborne dust clouds or lead to the evolution of vapours and gases which are readily inhaled and then absorbed into the bloodstream via the respiratory system. However, in some cases there is a potential risk from absorption of substances through the skin following dermal exposure, usually due to direct contact with organic liquids but sometimes through absorption of vapours.

Assessing skin exposure isn’t easy. There are well established methods for estimating exposure to most common industrial chemicals by inhalation but there are a number of major difficulties involved in developing a good method for measuring uptake through the skin.

Starting in 2003, a major International conference has been held devoted to the science of skin exposure to chemicals at work and from the environment. BOHS hosted the fourth conference in Edinburgh two years ago. The latest conference was held in Toronto, Canada at the beginning of June. One of the keynote presentations was given by John Cherrie of the Institute of Occupational Medicine, and a former president of the BOHS. He provided a good summary of the current state of knowledge on skin exposure assessment. His presentation has just been posted on Slideshare and can be viewed below.

Image from jelaga @ stock.xchng

Testing walk-in spray booths

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Spray painting inside a walk-in booth (photo credit: HSE)

We recently received a query from a client who carry out paint spraying of isocyanate based two pack paints in a large walk-in type spray booth. They wanted us to carry out sampling to help them to decide when it was safe to enter the booth without their workers wearing their air fed masks. This sounds like a good idea. In fact it’s essential for workers to know when the paint spray has been completely cleared from the booth. Isocyanates are very potent respiratory sensitisers causing asthma in susceptible individuals. Anyone sensitised to isocyanates will experience asthmatic symptoms even if they are only exposed to very low concentrations. However, air sampling isn’t the best way to determine the “clearance time”.

If it was possible to use a direct reading instrument that gives a reading of the instantaneous concentration it would be relatively easy to determine when the booth was cleared. Unfortunately there isn’t a direct reading instrument that can be used for isocyanates. Sampling has to be carried out using an integrating technique – that means that a sample is collected over a period of time, and, after it has been analysed in a laboratory, it is then possible to determine the average concentration present during the sampling period. To determine the  “clearance time” a series of samples would have to be taken one after another. This would be expensive (the analysis isn’t cheap) and the standard method for isocyanates is not particularly good. The samples are collected by bubbling air through a reagent dissolved in toluene and as a low detection limit would be required it’s difficult to take samples over a short period.

Consequently its better to use a different approach, releasing smoke into the enclosure and then timing how long it takes for it to be completely removed from the booth. This method is quicker, less messy and much less expensive. The test can also be used to check that there are no leaks from the booth – any smoke escaping should be clearly visible. The Health and Safety Executive explain how to carry out this test in their publication “Controlling isocyanate exposure in spray booths and spray rooms” which can be downloaded from their website here.

The following videos show a smoke test taking place in a typical booth.

Once the clearance time has been established it’s important to ensure that anyone who works in the booth is informed and a notice posted at the entrance to the booth, something like this:

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The HSE would like to see automatic clearance time indicator fitted on walk-in spray booths, but in my experience few have them. This is something that should really be addressed by the manufacturers and suppliers of the equipment. A new booth should already have them fitted, and clearance times should be established during the commissioning of the equipment after it’s been installed.

Following on from the initial test checking the clearance time should also form part of the statutory thorough examination and test required for LEV systems under COSHH Regulation 9. All engineering controls deteriorate over time, so the time taken for the contaminants to clear is likely to increase, even with a well maintained booth.

Glove boxes

Glove boxes are often used in the pharmaceutical industry to control highly toxic “active” agents used in drug formulations. In principle they should provide a high degree of protection for the user. The contaminant is completely contained inside an extracted enclosure while the worker is outside. So when we’re carrying out a risk assessment and spot that the work is carried out inside a glove box we might assume that exposure will be well controlled. However, we have to be careful – sometimes the opposite is true.

positive pressure glove box

Looking at the above picture you can see that the gloves are sticking out of the enclosure. This is a good indication that the enclosure is under positive pressure. This means that contaminated air will leak out through any gaps or breaches in containment, potentially bringing contaminants out with it to which the operator will be exposed.

Such “positive pressure” booths are often used for quality considerations – to protect the product from contamination – and this is probably the case here.