Construction chemicals are additives that are used with concrete, cement, and other construction materials to provide additional durability and workability to various structures. The type of chemical to be used depends on the size and nature of the project. But along with the advantages, comes a few hazards as well. Explained below are some of the hazardous construction chemicals in the construction site.
Alkylphenols
Alkylphenols are a family of organic compounds obtained by the alkylation of phenols. The term is usually reserved for commercially important propylphenol, butylphenol, amylphenol, heptylphenol, octylphenol ethoxylates (OPEs), nonylphenol ethoxylates (NPEs), dodecylphenol and related “long chain alkylphenols” ‘(LCAPs)’. Alkylphenols have been in use in industry for nearly 50 years. Initial use was in detergents and as additives to fuel. Importantly they are a component in phenolic resins. Alkylphenol compouds are also used in the manufacture of thermoplastic elastomers, antioxidants and fire retardants. Further downstream in other compounds they can be found in adhesives, paints and coatings and high performance rubber products. Another alkylphenol derivative, alkylphenol phosphite, can be used as a UV stabilizers in plastics.
Human exposure to alkylphenols and alkylphenol ethoxylates may come through contaminated foods such as fish and drinking water. Indoor air and to a lesser extent, outdoor air may contain levels of octylphenol.
Asbestos
The EPA attempted to ban asbestos in 1989, but the ban was overturned in 1991 in appeals court, which ruled that the EPA had not met the burden of scientific proof required by TSCA that the substance posed an unreasonable risk to health or the environment.
Around 15,000 people in the U.S. die each year from asbestos-related illness. Once that ban was overturned the EPA never again attempted to ban another hazardous substance. These days, asbestos fibers are found in these common building products- Joint compound, Floor tile, Cement board, Pipes and Shingles
Exposure to asbestos can lead to pulmonary diseases (diseases of the lungs) including something you may hear on a commercial: mesothelioma, a form of lung cancer that is usually fatal.
Formaldehyde
Formaldehyde is a known carcinogen according to the World Health Organization(WHO). It was grandfathered in under the original 1976 version of the TSCA and, therefore, has never been fully assessed by the EPA.
It is an irritant to the mucous membranes, the thin tissue inside your nose and other respiratory passages and inside your gut. Long term exposure can cause asthma-like respiratory problems and skin irritation such as dermatitis and itching.
Formaldehyde is commonly found in polymers used in plywood and carpet manufacture as well as resins important to the manufacture of paper products and polyurethane foam insulation manufacturing.
Silica
Silica is a component of bricks, glass, and concrete, and OSHA regulates the dust with Permissible Exposure Limits (PELs). With the new law, the EPA may place even more stringent restrictions on silica.
When silica dust is inhaled, it can travel deep into the lungs and cause disabling or fatal lung problems including silicosis and lung cancer. It can also cause kidney cancer. Other chemicals that have not yet been assessed include C8, also known as perfluorooctanoic acid (PFOA), Styrene, and Bisphenol A.
C8 was an integral part of DuPont’s Teflon non-stick coating. DuPont and seven other chemical manufacturers came to an agreement with the EPA to voluntarily stop using it for that type of coating. However, it is used in other products that are marketed to shed water or keep food from sticking. It may be a component of building material.
Diisocyanates
Di-isocyanates (die-i-so-sie-uh-nates) have been in use since the 1940s, mainly in polyurethane products- Rigid and flexible foams, Coatings, Adhesives, Sealants and Elastomers
The occupational risk and hazard of these chemicals is limited to people who come into contact with it in its vapor or liquid form that occurs as a byproduct of manufacture. You may be impacted because polyurethane foam building insulation, paints and coatings, and other products will probably become heavily regulated or eliminated after the EPA review.
Flame retardants
Flame retardant is a term used for a group of chemicals that are used to inhibit the ignition or spread of fire. Halogenated flame retardants are related to PCBs, another potentially harmful substance, and have been linked to- Cancer, Birth defects, Endocrine disruption and Developmental problems in children
It can be found in thermal insulation boards and many textiles.
Polyurethane
Polyurethane is generally considered one of the least preferable of the primary alternatives currently in use to replace chlorinated plastics. Thermoplastic polyurethane (TPU) is made up of polyols and diisocyanates. Diisocyanates are severe bronchial irritants and asthmagens associated with chronic exposures that can be fatal at high exposures for sensitive individuals. TPU is made from a variety of highly hazardous intermediary chemicals, including formaldehyde (a known carcinogen) and phosgene (a highly lethal gas used as a poison gas in World War I that, in turn, uses chlorine gas as an intermediary). In combustion, polyurethanes emit hydrogen cyanide and carbon monoxide. Polyurethane can be found in a wide array of building materials, including rigid foam (board and sprayed insulation, flexible foam (padding for furniture and bedding), coatings and paints, adhesives, sealants and elastomers (such as wood sealers and caulks), window treatments, resin flooring, gaskets and other thermoplastics, and fabrics. In the analysis of plastics used in health care, polyurethane may be more preferable than PVC on the spectrum, but is still more problematic than other plastics, including polyethylene (non-chlorinated types), polypropylene, and thermoplastic polyolefins. Research and development dollars invested toward sustainably grown bioplastics are even more promising because they move us away from our over reliance on petrochemical plastics.
PVC
Polyvinyl chloride (PVC) – commonly referred to as vinyl – is the most widely used chlorinated plastic polymer in the United States, with 14 billion pounds per year produced in the U.S. alone. The building industry is responsible for more than 75% of that PVC use. To make PVC flexible and versatile, the plastics industry can add a soup of chemicals to PVC, many of which raise concerns for human health and the environment. The healthcare industry has targeted PVC and other chlorinated plastics for elimination due primarily to a family of chemicals of concern uniquely associated with chlorinated plastics: dioxins. Dioxins are created during the production/ manufacturing process and when chlorinated plastics are burned accidentally or intentionally during disposal.
Halogenated flame retardants
Flame retardants are chemicals incorporated in construction materials during manufacturing to slow down or stop the spread of flames either by forming a protective film or by inhibiting chemical reactions that support combustion in case of a fire break out.
When heated, these retardants degrade into toxic substances in gaseous form which then mix with dust and get into the body through ingestion or inhalation. They can cause disruption of hormones especially thyroid, adverse developmental problems in foetus and children, immunotoxicity, cancer and reproductive problems.
Cadmium
This is a soft malleable metal that is resistant to corrosion, insoluble in water and non-flammable when in solid state. It has been widely used on other metals especially steel as corrosion resistant plating. Its compounds have also been used to stabilize plastic and to colour glass since they are available in red, yellow and orange pigments.
Cadmium fumes, highly soluble compounds or fine dust can cause pulmonary oedema (accumulation of fluids in the air spaces and tissue in the lungs), pneumonitis (inflammation of lung tissue) and death.
Volatile organic compounds
VOCs are naturally occurring or man-made chemicals with a low boiling point resulting in large numbers of their molecules vaporising and filling the surrounding air.
In building and construction, VOCs are commonly found in solvents, paint, plastics, synthetic fibres, adhesives and protective coatings. Some of them such as formaldehyde which emanates from paint have boiling points as low as just -190C.
VOCs usually cause irritation to eye and respiratory track, dizziness, memory impairment, damage to the kidney, liver and central nervous system. Some have also been found to cause cancer in animals and humans.
Halogenated flame retardants
‘Flame retardants (FR) are compounds that when added to manufactured materials, such as plastics and textiles, and surface finishes and coatings that inhibit, suppress, or delay the production of flames to prevent the spread of fire.’ Flame retardants are broadly classified into halogenated and non-halogenated flame retardants Flame retardants are found at increasing levels in household dust, human blood and breast milk, and wild animals. The chemicals are widely distributed in the outdoor environment with the highest concentrations in the Arctic and marine mammals. Many halogenated flame retardants are found to be persistent, bioaccumulative and/or toxic (PBT). Persistent’ means that the compounds do not break down into safer chemicals in the environment through time, probably, in the case of fire retardants, many years.
Mercury
Mercury is a chemical element. It exists in several forms: elemental or metallic mercury (a ‘heavy metal’), inorganic mercury compounds, and organic mercury compounds. Elemental or metallic mercury is a shiny, silver-white metal and is liquid at room temperature. If heated, it is a colourless, odourless gas. Mercury is now mainly used in the chemical industry as catalysts. It is also used in some electrical switches and rectifiers.
Previously its major use was in the manufacture of sodium hydroxide and chlorine by electrolysis of brine. These plants will all be phased out by 2020. It was also commonly used in batteries, fluorescent lights, felt production, thermometers and barometers. Again, these uses have been phased out.
Mercury and most of its compounds are extremely toxic. Mercury poisoning can result from exposure to water-soluble forms of mercury (such as mercuric chloride or methylmercury), inhalation of mercury vapour, or, the most common exposure, eating seafood contaminated with mercury.
Toxic effects include damage to the brain, kidneys and lungs. Mercury poisoning can result in several diseases, including acrodynia (pink disease), Hunter-Russell syndrome and Minamata disease.
Symptoms typically include sensory impairment (vision, hearing, speech), disturbed sensation and a lack of coordination. The type and degree of symptoms exhibited depend upon the individual toxin, the dose, and the method and duration of exposure.
Polychlorinated Biphenyls (PCBs)
Polychlorinated Biphenyls (PCBs) are synthetic organic chemicals that were manufactured for use in various industrial and commercial applications – including oil in electrical and hydraulic equipment, and plasticisers in paints, plastics and rubber products – because of their non-flammability, chemical stability, high boiling point and electrical insulation properties.
Conclusion
It is important to note that these are not only chemicals that are prevalent, there are several others too. Few of them are only marked. With better awareness we can make more calculated and informed decisions