Health Hazards in Construction- Chemical Hazards.
- Identify major health hazards common to the construction
industry
- Describe both acute & chronic health hazards
- Protect themselves from safety & health hazards
- Recognize employer requirements and to protect workers from
- exposure to safety & health hazards.
- Introduction.
- Construction Diversity.
Construction work is dynamic, diverse, and constantly changing. This poses a great challenge in protecting the safety and health of construction workers. Construction workers are at risk of exposure to various health hazards that can result in injury, illness, disability, or even death.
- Risk Factors in Construction.
- Factors increasing the health risk of construction workers include:
- Constantly changing job site environments and conditions
- Multiple contractors and subcontractors
- High turnover; unskilled laborers
- Constantly changing relationships with other work groups
- Diversity of work activities occurring simultaneously
- Exposures to health hazards resulting from own work as
- Well as from nearby activities (“bystander exposure”)
- Health Hazard Categories.
Four major categories of health hazards to which construction
workers may be exposed:
- Chemical Hazards (i.e. dusts, mist, fumes, gases, and vapors)
- Physical Hazards (i.e. heat, noise, vibration)
- Biological Hazards (i.e. plants, insects, animals, and microorganisms)
- Ergonomic Hazards (i.e. awkward postures and lifting, pushing, and pulling).
Note: Ergonomic hazards are the most frequently occurring
health hazards in construction and the cause of most injuries.
Some Examples of Construction Health Hazards.
Occupations |
Potential
Health Hazards |
Brick
masons |
Cement
dermatitis, awkward postures, heavy loads |
Drywall
installers |
Plaster
dust, heavy loads, awkward postures |
Electricians |
Heavy
metals in solder fumes, awkward posture, heavy loads,
asbestos |
Painters |
Solvent
vapors, toxic metals in pigments, paint additives |
Pipefitters |
Lead
fumes and particles, welding fumes, asbestos dust |
Carpet
layers |
Knee
trauma, awkward postures, glue and glue vapor |
- Chemical Hazards.
Chemicals can exist in the form of:
- dusts, fumes, fibers (solids)
- liquids,
- mists
- gases,
- vapors
Chemicals are found in variety of products used at construction sites. Workers may also be exposed to chemicals generated during construction activities.
Examples of chemical hazards found in construction work:
- asbestos
- lead
- silica
- cadmium
- carbon monoxide
- welding fumes
- spray paints
- cutting oil mists
- solvents
- hexavalent chromium
- Routes of Exposure.
Chemicals can enter the body through:
- Inhalation: breathed in (Inhalation is typically the most common way chemicals can enter the body in a work situation.)
- Ingestion: accidental swallowing through eating, drinking, or smoking
- Absorption: absorbed through contact with skin or eyes
- Acute vs. Chronic.
There are generally two types of health effects from chemical
exposure, acute and chronic.
- Acute.
Appears immediately or within short time following exposure,
(minutes or hours); death possible from some hazardous substances.
Typically, sudden, short-term, high concentration.
Examples:
- Headache, collapse, or death from high levels of carbon monoxide
- Eye and throat irritation from exposure to ammonia
- Death and/or serious injury resulting from exposure to Hydrogen
- Chronic.
Usually develops slowly, as long as 15-20 years or more.
Continued or repeated for a prolonged period, usually years.
Examples:
- Lung cancer, asbestosis, mesothelioma from exposure to asbestos
- Silicosis from exposure to crystalline silica
- Leukemia from exposure to benzene
- Asbestos.
Construction workers may be exposed to asbestos during
demolition or remodeling of older buildings built before 1980 which can contain
asbestos insulation, or other asbestos containing products.
Asbestos removal can only be done by specially trained
asbestos workers.
Asbestos exposure can cause breathing problems, lung cancer
and cancer of the lung lining many years after exposure.
- Welding Fumes.
Welding fumes contain a variety of chemicals depending on
what is being welded on, chemical makeup of welding rods, fluxes and shielding
gases.
Generally, welding in confined spaces or welding on
stainless steel which generates hexavalent chromium, are the most hazardous
welding activities.
- Chromium Hexavalent (CrVI).
Hexavalent chromium compounds, exist in several forms:
- Industrial uses of hexavalent chromium compounds include chromate pigments in dyes, paints, inks, and plastics; chromates added as anticorrosive agents to paints, primers, and other surface coatings; and chromic acid electroplated onto metal parts to provide a decorative or protective coating.
- Hexavalent chromium can also be formed when performing "hot work" such as welding on stainless steel or melting chromium metal.
- Health Effects of hexavalent chromium exposure include: Lung cancer; Asthma; Nasal perforation, ulceration, and dermatitis.
- Solvents.
Millions of workers are exposed to solvents daily.
Health hazards associated with solvent exposure include
toxicity to the nervous system, reproductive damage, liver and kidney damage,
respiratory impairment, cancer, and dermatitis.
Solvents share many chemical, physical, and biological properties
that warrant national attention be directed to them as a group.
Many solvent groups or individual substances have special properties
requiring more specialized control measures.
A variety of solvents with varying degrees of toxicity are
used in construction, they are in paints, glues, epoxies, and other products.
Generally, the possibility of exposure to excessive amounts
of solvent. vapors is greater when solvents are handled in enclosed or confined
spaces.
Solvents can:
- Irritate your eyes, nose, or throat.
- Make you dizzy, high, sleepy, give you a headache or cause you to pass out.
- Affect your judgment or coordination, Cause internal damage to your body.
- Dry out or irritate your skin.
- Crystalline Silica.
What is crystalline silica?
Crystalline silica is a basic component of soil, sand,
granite, and many other minerals.
Quartz is the most common form of crystalline silica.
Cristobalite and tridymite are two other forms.
All three forms may become respirable size particles when workers
chip, cut, drill, or grind objects that contain crystalline silica.
- Hazards of crystalline silica.
Seriousness of the health hazards associated with silica
exposure is demonstrated by the fatalities and
disabling illnesses that continue to occur in sandblasters
and rock-drillers.
Has been classified as a human lung carcinogen.
Breathing crystalline silica dust can cause silicosis, which
in severe cases can be disabling, or even fatal.
- Symptoms of silicosis.
- Chronic/classic silicosis: 15–20 years of moderate to low exposures; symptoms may or may not be obvious; chest x-ray to determine if there is lung damage; worker may experience shortness of breath upon exercising and have clinical signs of poor oxygen/carbon dioxide exchange.
- Accelerated silicosis: 5–10 years of high exposures to respirable crystalline silica. Symptoms include severe shortness of breath, weakness, and weight loss.
- Acute silicosis: a few months or as long as 2 years following exposures to extremely high concentrations of respirable crystalline silica. Symptoms of acute silicosis include severe disabling shortness of breath, weakness, and weight loss, which often leads to death.
- Where are construction workers exposed?
- Many different construction activities.
- Most severe exposures generally occur during abrasive blasting with sand to remove paint and rust from bridges, tanks, concrete structures, and other surfaces.
- Other construction activities that may result in severe exposure include jack hammering, rock/well drilling, concrete mixing, concrete drilling, brick and concrete block cutting and sawing, tuck pointing, tunneling operations
- Protect against exposures to crystalline silica.
- Replace crystalline silica materials with safer substitutes, whenever possible.
- Use engineering or administrative controls, where feasible, such as local exhaust ventilation and blasting cabinets.
- Use protective equipment or other protective measures (e.g. respiratory protection).
- Use all available work practices to control dust exposures (e.g. water sprays).
- Wear disposable or washable work clothes and shower if facilities are available. Vacuum the dust from your clothes (with a HEPA vacuum) or change into clean clothing before leaving the work site.
- Participate in training, exposure monitoring, and health screening and surveillance programs to monitor any adverse health effects.
- Do not eat, drink, smoke, or apply cosmetics in areas where crystalline silica dust is present and wash your hands and face outside of dusty areas before performing any of these activities.
- Lead.
Construction workers are and can be exposed to lead during
many constructions related activities to include:
- Demolition of structures.
- Flame-torch cutting.
- Welding.
- Use of heat guns, sanders, scrapers, or grinders to remove lead paint.
- Abrasive blasting of steel structures.
- Excavation work in areas with lead contamination (e.g. burn pits and landfills)
- Other construction and hazardous waste related activities.
- How You Can Become Exposed to Lead.
Lead is an ingredient in thousands of products widely used throughout
industry, including lead-based paints, lead solder, electrical fittings and
conduits, tank linings, plumbing fixtures, and many metal alloys.
Although many uses of lead have been banned, lead-based
paints continue to be used on bridges, railways, ships, and other steel
structures because of its rust- and corrosion-inhibiting properties.
Also, many homes were painted with lead-containing paints.
Significant lead exposures can also occur when paint is
removed from surfaces previously covered with lead-based paint.
OSHA has very strict regulations for worker exposure to
lead.
Major Elements of OSHA’s Lead Standard:
A permissible exposure limit (PEL) of 50 micro-grams of lead
per cubic meter of air, as averaged over an 8-hour period.
Requirements for engineering controls and work practices,
where feasible, to reduce worker exposure.
Requirements for good personal hygiene practices, such as
washing hands before eating and taking a shower before leaving the worksite.
Requirements for protective clothing and, where necessary,
with respiratory protection.
A requirement that employees exposed to high levels of lead
be enrolled in a medical surveillance program.
- Confined Spaces.
Exposure to chemicals or lack of oxygen in confined spaces
can be deadly.
Airborne chemicals can quickly reach dangerous levels in confined
spaces that are not ventilated.
Carbon monoxide, hydrogen sulfide, welding fumes and solvent
vapors are typical confined space chemical hazards.
In some confined spaces, oxygen deficiency will cause the person
entering to instantly collapse.
As many co-workers who attempt rescue die in confined spaces
as the original worker who collapsed.
- Hazard Communication.
- HazCom Background
Hazard Communication (HazCom) = Right To Know
Ensures that hazards of all chemicals produced or imported
are evaluated, and that information concerning their hazards is transmitted to
employers and employees.
Transmittal of information includes container labeling and other
forms of warning, materials safety data sheets, and employee training.
The HazCom standard establishes uniform requirements to make
sure the hazards of all chemicals in the workplace are evaluated and the
information is passed on to affected.
- How HazCom Works.
Chemical Manufacturers Must:
Determine the hazards of each product; and communicate
information to customers through labels and Material Safety Data Sheets (MSDS).
Employers Must:
Identify and list chemicals in the workplace; obtain MSDSs
and labels for each chemical; and develop and implement written programs that
include chemical lists, labels, MSDSs, personal protective equipment (PPE), and
employee training.
Employees Must:
Comply with all elements of the HazCom program by following
the warnings, cautions on MSDSs and on chemical labels; and wear and maintain
required PPE.
- Training.
Employee training plans must include general and site-specific
information:
- How the HazCom program is implemented.
- Hazards of the chemicals in the area.
- Measures employees can take to protect themselves.
- Location and use of PPE, if required.
- Methods and observations workers can use to detect the presence of a chemical.
- Labels and Warnings.
Each container must
be labeled, tagged, or marked with the identity of the chemical contained, and
must show appropriate hazard warnings.
Labels must be
legible, in English, and prominently displayed.
- SDS.
Old terminology for many years was MSDS or Material Safety
Data Sheet under GHS, the new terminology is Safety Data Sheet (SDS) and
provides comprehensive information for use in workplace chemical management.
The documents provides information and advice on safety
precautions.
The new SDS should contain 16 heading as per below figure.
So, what do you do if you find a chemical in your workplace
and after reading the label still are not sure how you should handle it? You
should consult the safety data sheet or SDS for the chemical.
There should be one available from every chemical you might
encounter and if there is not, then request one immediately.
- Material Safety Data Sheets (MSDSs).
Chemical manufacturers must:
- Develop an MSDS for each chemical they produce or import.
- MSDS must be provided automatically at the time of the initial shipment of the product.
- MSDS must be in English and include information regarding the chemical identity.
Information must be provided:
- On the characteristics, both physical and chemical.
- Known acute and chronic health effects and related health information.
- Exposure limits.
- Whether the chemical is considered to be a carcinogen.
- Precautionary measures.
- Emergency and first-aid procedures.
- The identification of the organization that prepared the MSDS.
Some items that must be included on an MSDS:
- The characteristics of the chemical, both physical and chemical Known acute and chronic health effects and related health information.
- Exposure limits.
- Whether the chemical is a carcinogen.
- Precautionary measures.
- Emergency and first-aid procedures. The identification of the organization that prepared the MSDS.