Expert
forecast on emerging chemical risks related to occupational safety and health
by
European
agency for safety and health at work, 2009
The Community strategy on health and safety at work 2002-2006
called on the European Agency for Safety and Health at Work to ‘set up a risk
observatory’ to ‘anticipate new and emerging risks’. Within this context, a series of four expert
forecasts were formulated with the aim of providing as comprehensive as
possible a picture of the potential emerging risks in the world of work. Three reports on emerging physical risks, biological
risks and psychosocial risks have already been published. This publication (the last one of the series)
presents the results of the forecast on emerging chemical risks related to occupational
safety and health based on an expert survey and a literature review.
Method
Within the scope of this project, an ‘emerging occupational safety
and health (OSH) risk’ has been defined as any occupational risk that is both
new and increasing.
By new it means that:
•
the risk was previously unknown and is caused by
new processes, new technologies, new types of workplace, or social or organizational
change; or
•
a longstanding issue is newly considered as a
risk due to a change in social or public perceptions; or
•
new scientific knowledge allows a longstanding
issue to be identified as a risk.
The risk is increasing if:
•
the number of hazards leading to the risk is growing;
or
•
the likelihood of exposure to the hazard leading to
the risk is increasing (exposure level and/or the number of people exposed); or
•
the effect of the hazard on workers’ health is
getting worse (seriousness of health effects and/or the number of people
affected).
To formulate this expert forecast, a questionnaire-based survey
was run in three consecutive rounds following the Delphi method. This method
was chosen to avoid individual, non-scientifically founded opinions and to
verify whether a consensus was reached among the respondents; 174 experts in
the first survey round and 152 experts from each of the second and third rounds
were invited to participate in the survey following their nomination by the
Agency’s Focal Points and Topic Centre Research.
Thirty-one valid questionnaires from the first round, 35 from the
second round and 49 from the third were returned from 64 organizations covering
19 European Member States as well as Iceland and Switzerland. The response
rates were 31% (first survey round), 35% (second round) and 32% (third round).
Participating experts were required to have at least five years’ experience in
the field of OSH and chemical risks. The majority of respondents were managers
in an OSH organization, or OSH researchers.
Top Emerging Risks
Particles
Among the ‘top ten’ emerging risks, three (nanoparticles and
ultrafine particles, diesel exhaust and man-made mineral fibers) have in common
their physico-chemical state as particles. According to the Fourth European Working
Conditions Survey
19.1% of the EU-27 workforce reported in 2005 that they ‘breathe in smoke,
fumes, powders or dust’.
The risks posed by ‘nanoparticles and
ultrafine particles’ are by far the strongest agreed as emerging by the experts. Applications of nanotechnology are mainly
found in:
•
information and communication technologies;
•
environmental and energy technologies;
•
transport, aviation and space;
•
agriculture and nutrition;
•
medical applications;
•
cosmetics;
•
military technologies.
The nanotechnology industry is expected to grow rapidly into a
global, multi-billion euro market and to employ 10 million workers worldwide by
2014. However, very little research has
been performed on the health and safety effects of nanoparticles (NPs). NPs can have very different properties from
the same materials at the macro scale. There
are indications that the toxicity of particles increases with decreasing
diameter and increasing surface area, thus challenging current mass-based risk
evaluation approaches. Several studies
indicate that, once in the body, NPs can translocate to organs or tissues
distant from the portal of entry. Durable, biopersistent NPs may bioaccumulate
in the body – in particular in the lungs, the brain and the liver. Ultrafine particles have been found to act as
an important environmental risk factor for cardiopulmonary mortality and there
is considerable evidence that some NPs are toxic to human health. The basis of
toxicity is not fully established, but appears to be primarily expressed
through an ability to cause inflammation. NPs could also act like haptens to modify
protein structures, hence raising the potential for autoimmune effects. Damage to the cells through oxidative stress,
believed to induce many diseases such as cancers, is also suggested. However,
decisive scientific information is still lacking.
Although the quantitative data needed for satisfactory risk assessment
are still missing, sufficient information is available to begin preliminary
assessment and to develop interim working practices to reduce workplace
exposure. The manufacturing phase of nanomaterials
as well as maintenance and clean-up of equipment used to produce NPs are known
to be a source of exposure. Further
research should concentrate on the complete life-cycle of a given nanomaterial
in order to identify all exposure situations and the workplaces concerned. In parallel, further research should be
undertaken to guarantee the development of ‘responsible’ nanotechnology which
integrates health and safety considerations.
Exposure to diesel
exhaust is the second most emerging risk highlighted in the forecast. According to the CAREX (CARcinogen EXposure)
database, at the beginning of the
1990s, 3.1 million workers in the EU-15 were exposed for at least 75% of their
working time to diesel exhaust, making it the fourth most common carcinogen
found in the workplace after solar radiation, tobacco smoke and crystalline
silica.
Hazardous levels of diesel exhaust can be found in occupations
ranging from mining to driving diesel-fuelled trucks or forklifts. Diesel exhaust is made up of a complex mixture
of thousands of fine particles, gases and vapours. The major components are carbon dioxide,
carbon monoxide, nitrogen dioxide, nitric oxide, particulate matter and sulphur
dioxide. Diesel engine exhaust is
classified as ‘probably carcinogenic to humans’ (Group 2A) in the International
Agency for Research on Cancer’s classification.
More specifically with regard to lung cancer, a positive
association between diesel exhaust emissions and lung cancer is suspected but
is still controversial. A link between emissions
from diesel-fuelled engines and non-cancer damage to the lung has also been
found. More research is needed on the health effects of such particulates.
Man-made
mineral fibers are divided into siliceous and non-siliceous. Fibers with a geometric diameter less than 3
μm may reach the alveolar zone of the lungs. While the size of the fibers is acknowledged
to be linked to their harmful toxic effects (the longer and thinner the fibers,
the more dangerous they are), standard air sampling methods do not allow
precise measurement of fiber size. Specific
fiber dimensions hypothesized to have a biological activity have been proposed
but need to be evaluated in epidemiologic studies. In general, fibrous
structure increases inflammatory, cytotoxic and carcinogenic potential. Oxidizing stress of the cells can also occur,
especially in the case of repetitive exposure.
Manufacturers continuously strive to reduce the biopersistence of
siliceous fibers by modifying their compositions – a process favorable to
occupational health. However, the
compositional changes make it more difficult to obtain comparable data from epidemiological
studies. As a consequence, very few toxicological data are available for these
new products. Aluminium silicate wool (ASW) – more commonly called refractory
ceramic fibers (RCFs) – is carcinogenic category 2 in the EU classification.
ASW/RCF products put on the market are labelled according to
Directive 67/548 for substance and preparations. According to the European Ceramic Fibers
Industry Association (ECFIA), the manufacturing industry also labels articles
containing ASW/RCFs (though not required by the regulations). However, a study
by the French agency Afsset found:
•
there is no specific code or labelling clearly
indicating their presence in items and equipment;
•
RCFs cannot be reliably differentiated from other fibers
by simple visual examination.
The Afsset survey also found that some companies claim to be
unaware of the exact nature of the fiber-containing components they order from
their providers and most of them do not carry out any measurements to evaluate
the level of workers’ exposure to RCFs. The
results of many exposure measurements carried out by producers and prevention organizations
are available and could be a help to these companies.
Continuous filament fibers, which are unclassified in the EU
classification of carcinogens, have been little studied and there is a need to
acquire knowledge on their toxicity. There is also a particular lack of
information on special purpose glass fibers. As for carbon fibers, some information
inclines towards caution because of their capacity to break and to create
ultrafine particles. There are few
toxicological data on tungsten oxide and magnesium sulphate whiskers, or on
alumina fibers, while silicon carbide whiskers appear carcinogenic in animals. Potassium titanate fibers are suspected to be
carcinogenic. The toxicity of other
non-siliceous man-made mineral fibers has been little investigated, but they
seem to be biopersistent.
Although some man-made mineral fibers contain up to 25% additives,
studies rarely take their presence into account. Workers handling fiber-based products,
especially during laying, maintenance or removal operations, may be highly
exposed.
Allergenic
and Sensitizing Agents
Another three risks identified as emerging were mentioned by the
respondents with a view to allergies and sensitizing effects. These are epoxy resins, isocyanates and dermal
exposure.
Epoxy resins are one of the most important and widely used
polymeric systems. They are used in adhesives,
sealants, inks, varnishes and reinforced polymer composite structures with
glass fiber, carbon fiber or metal substrates, paints and coatings, including
protective coatings of canned food. The
continuous demand for always newer generations of epoxy resins and derived
products with enhanced properties may introduce new, unknown adverse health
effects. These effects may be caused by uncured
epoxy resins or by the variety of curing agents, diluents or other constituents
used in epoxy formulations. Epichlorohydrin,
used to obtain epoxy resins, is classified as ‘carcinogenic category 2’ in the
EU classification. Bisphenol A, the
other coupling constituent, was found to induce allergic contact dermatitis
(ACD) and to be a weakly estrogenic monomer.
Epoxy resins themselves
have become one of the main causes of occupational ACD. Skin sensitisation of the hands, arms, face
and throat as well as photosensitisation has also been reported. Some of the
components can also cause irritation of the eyes and respiratory tract, contact
urticaria, rhinitis and asthma. Workers
in the production of epoxy resins and workers in the manufacture of composite
products, in the electrical and electronics industry, and painters may be at
risk. Epoxy skin sensitization is particularly
problematic in the construction industry where a safe and healthy working environment
(e.g. clean room) and the use of protective clothing (e.g. gloves) is less common
and/or less practical. Wherever
possible, one-part instead of two-part epoxies should be used to reduce the
risk of dermal contact during hand mixing. Contact with incompletely cured epoxy resins
should be avoided. The proper
identification of the epoxy system involved in the process is essential for the
selection of appropriate prevention measures.
A further emerging chemical risk identified in the survey is the
increasing use of isocyanates. Again
exposure to isocyanates does not only occur at the production stage but also
when polyurethane products containing isocyanates are used (e.g. when
spraying), are processed (e.g. grinding or welding), or when they undergo thermal
or chemical degradation. Isocyanates are
widely used in the manufacture of flexible and rigid foams, fibers, elastomers,
building insulation materials, paints and varnishes. Workers in car body repair shops may, for
example, be exposed during the abrasive process of a car body, as isocyanates
may be released into the air as a consequence of thermal degradation of the
isocyanate-containing car paint induced by the heat generated in the abrasion.
Isocyanates are powerful irritants to the mucous membranes of the
eyes and of the gastrointestinal and respiratory tracts. Direct skin contact can cause serious
inflammation and dermatitis. They are also powerful asthmatic sensitizing
agents. Death from severe asthma in some
sensitized subjects has been reported. Early
recognition of sensitization, coupled with prompt and strict elimination of the
source of exposure, is essential to reduce the risk of long-term or permanent
respiratory problems in sensitized workers.
Dermal
exposure is a major route of occupational exposure to dangerous substances. In EU Member States, skin diseases are the
second most common occupational diseases after musculoskeletal disorders (MSDs);
contact dermatitis being the most common.
Other work-related skin diseases include chemical burns, contact
urticaria, photodermatitis, contact leukoderma (Vitiligo), infectious
dermatitis and skin cancer.
Chemicals are responsible for 80–90% of skin diseases. The skin of the hands and other body parts can
be affected by indirect exposure to airborne substances (e.g. face, neck) or
when contaminated hands touch other body parts (e.g. hand-to-face contact). In
the construction industry, chromate is the most important allergen followed by
epoxy resins and cobalt. Natural rubber
protein (latex) is another major occupational allergen, in particular in the
healthcare sector. Soaps, detergents and
solvents can cause dermatitis as they remove the surface lipids and dissolve
the natural protective barrier of the skin. Allergies from exposure to
fragrances have been observed among masseurs, physiotherapists and geriatric
nurses. The use of protective gloves is
controversial due to other influencing factors such as the wet atmosphere inside
the glove.
There are no ‘dermal OELs’. Two reasons are the uncertainties in
the quantification of the dermal exposure level and the meagre toxicological
data available on health effects from dermal exposure – especially for repeated
exposure, exposure to diluted preparations, and combined exposures to various
chemicals or to other factors such as humidity. Within the European project RISKOFDERM,
determinants of dermal exposure, exposure control measures and default dermal
exposure values particularly useful to small and medium enterprises (SMEs) have
been defined and integrated into a risk assessment toolkit.
Sector
Specific Chemical Risk
Other major emerging risks identified are specific to certain
workplaces; for example the exposure to dangerous substances during waste
treatment activities and in the construction industry. It is interesting to note that these jobs are
neither in the chemical industry nor in industries where chemicals are used
intentionally in the work process, but rather where dangerous substances are
incidental products of the work.
Dangerous
substances in waste treatment activities
were also agreed as emerging risks in another expert survey on emerging
biological risks.
Waste management is considered one of
the most hazardous occupations with an illness rate 50% higher and an
infectious diseases rate six times higher than in other workers. European and national waste regulations were
adopted in the 1990s primarily for environmental purposes (i.e. to reduce the
volume of waste sent to landfill) and, as a consequence, do not integrate OSH
aspects enough. The amount of waste
generated in the EU is growing. Municipal solid waste (MSW) accounts for a
relatively small proportion of total waste, with the largest volume of waste
being generated by mining, manufacturing, construction and demolition
activities.
Up to 110 different volatile organic compounds (VOCs) have been
found during waste collection and at compost plants, landfills and resource
recovery plants. Landfill workers,
compost workers and waste collectors are also exposed to high levels of dust. While an increase in the recycling of car
components, plastics and electronic products is expected, there are concerns
that waste electrical and electronic equipment (WEEE) and end-of-life vehicles
(ELVs) contain hazardous materials such as lead, cadmium, mercury and
polychlorinated biphenyls (PCBs). In
incineration processes, the pollutants most often detected are dioxins, furans
and PCBs. The handling of medical waste presents
extra challenges such as the risk of contamination with sharps.
The health effects depend on the type of waste and substances. While it is not possible to completely
eliminate the chemical risks inherent to waste-related activities, the most
efficient prevention measure is to reduce the generation of dust, bioaerosols
and VOCs in the workplace. Technical
collective prevention measures and hygiene plans also contribute greatly to
reducing workers’ exposure. In any case, prevention should be adapted to the
specific characteristics of each branch of the waste sector and its activities.
The construction
sector is one of Europe’s largest industries. Construction workers are exposed to a variety
of dangerous substances in addition to noise, vibrations, falls from height and
musculoskeletal disorders. Respiratory
problems are widespread, not least due to asbestos – although its use is now
virtually banned in the European Union. If
inhaled, asbestos fibers can have serious health effects including asbestosis,
lung cancer and mesothelioma. There is
no known safe exposure level to asbestos. The more one is exposed, the greater the risk
of developing an asbestos-related disease. As the time between exposure to asbestos and
the first signs of disease can be as much as 30 years, the effects of past
exposure are only now apparent and are still expected to rise.
Construction workers may also be exposed to dust generated from
cutting or handling crystalline silica-based products. A major effect in humans of
the inhalation of respirable crystalline silica is silicosis. Crystalline silica is also classified as
‘Group 1 human lung carcinogen’ in the International Agency for Research on
Cancer’s classification. There is
currently no Occupational Exposure Limit (OEL) for respirable crystalline
silica at an EU level and existing national OELs vary. A European multi-sector agreement aims to
reduce workers’ exposure to crystalline silica dust through good practice in
the workplace.
Carpenters, in particular, are exposed to wood dust and thus have
an elevated risk of contracting nasal cancer. Workers in the construction industry are also
exposed to solvents, oils, resins and cement-based products containing
chromium (VI) which exacerbate the likelihood of skin problems. Important
contact with lead may also occur when working with old lead piping or removing
lead-based paints.
Chemical
Risks Combined with Organizational Factors
Last, but not least, some of the main emerging risks identified
are a consequence of the combination of chemical hazards and poor organizational
factors as demonstrated by the selection by respondents of the items ‘poor
control of chemical risks in small and medium enterprises’ and ‘outsourced activities
performed by subcontracted workers with poor knowledge of chemical risks’.
Micro-,
small and medium-size enterprises (SMEs) are socially
and economically important, representing 99.8% of all enterprises in the EU-25
in 2003. SMEs employ 66% of the workforce in the
private sector. They often experience difficulties in complying with their
obligation to assess and control chemical risks in the workplace as laid down by
EU Framework Directive 89/391/EEC and Directive 98/24/EC on chemical agents.
In
some cases, underlying factors are the limited technical expertise of SMEs and
the absence of a dedicated OSH professional. Most SMEs are aware of the hazards associated with
the hazardous substances they use but often only in very general terms. Moreover, there is generally a high level of
acceptance of the risks as being part of the job. Even when hazardous substances are monitored,
the results are not always representative of the actual exposure in the
workplace. Despite being feasible in many cases, the possibility of eliminating
or substituting the hazardous substance is generally not given enough
consideration. While appropriate
effective local ventilation is often lacking, there is an excessive tendency in
SMEs to rely on personal protective equipment (PPE). In general, workers are not consulted enough
about the implementation of controls on hazardous substances.
As
the cost of implementing controls is also one of the main barriers cited, one
of the challenges is to make OSH a benefit for SMEs. It is essential to target
awareness-raising interventions at SME managers as they play a key role in
determining the priority for implementing controls. Although SMEs see the distinctions between
health, safety and environment as irrelevant to them, they do want to know
exactly how to control chemicals in order to meet all regulatory requirements.
A number of easy-to-use tools are available but they need to be better shared
among the Member States and to be made available to SMEs in their national
language.
The
item ‘outsourced
activities performed by subcontracted workers with poor knowledge of chemical
risks’
– such as cleaning and maintenance activities – reflects the increasing concern
for multiple occupational risk factors and the importance of taking a holistic
approach when managing OSH risks. In particular, outsourcing and subcontracting
practices have increased during the last 15 years. Subcontracted workers increasingly perform
high-risk work across many industries. They generally have less control over working
times, often work in less skilled jobs, have fewer opportunities for training
and life-long learning, and subsequently less insight into their work
environment. All this contributes to
making outsourced workers more vulnerable to OSH risks. Outsourcing practices are also often
associated with an unclear repartition of legal responsibilities between the
host company and the contractor. There
is evidence that these new forms of employment have serious negative effects on
workers’ health and safety.
Parent-Thirion, A., Fernandez Macias, E., Hurley, J., Vermeylen, G., Fourth European Working Conditions Survey,
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Kauppinen, T. et al., CAREX – International Information System on
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for Safety and Health at Work, Expert forecast on emerging
biological risks related to occupational safety and health, Office for Official Publications of the
European Communities, Luxembourg, 2007. http://riskobservatory.osha.europa.eu/risks/forecasts/biological_risks/
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