“Going green” means construction workers are installing blown-in polyurethane foam insulation, which contains isocyanates – one of the most commonly reported causes of occupational asthma.
Assessment and Prevention of Isocyanate Exposures in the Construction Industry
Carrie Redlich, MD, MPH Yale University
New Haven, CT
Ph: 203-737-2817
Email: carrie.redlich@yale.edu
Year One:
This research reads like a math problem that contains certain givens:
Isocyanate chemicals are well-known sensitizers and one of the most commonly reported causes of occupational asthma.
The construction industry is one of the largest markets in North America for
products containing isocyanates, including polyurethane (PU) foam insulation.
What is unknown is the many different types of applications and work settings in which the construction industry uses PU products and the potential adverse health effects they pose for workers through skin and/or respiratory exposure.
What brings a sense of urgency to solving this problem is that “going green” means large numbers of construction workers are installing blown-in PU foam insulation and other products.
In Year One, Dr. Redlich discovered that a large number of different PU spray foam products are increasingly being used in new construction and renovation projects. Her database contains approximately 130 products used in construction. To better understand which products may present greater risk of isocyanate exposure, she gathered specifics about their use, physical form, type of isocyanate they contain, and the presence of other potentially harmful chemicals, among other parameters – when that information was available.
The Material Safety Data Sheets (MSDS) for many of these products are frequently inadequate on the risks of exposure. Some of the MSDS and technical data sheets omit recommended practices.
Others cite proprietary reasons for offering no information. MSDS may exist for the
finished fully-cured products, but MSDS for the single or two components that the user handles are often not readily available. As a result, there is a general lack of awareness of potential exposures and health risks to construction workers who apply them. Yet many of these products are marketed as “green,” which implies being good for the environment, and can mislead workers (and consumers) to assume there are no human hazards.
But workers can face real health hazards with these products. Over the past year, Dr. Redlich has diagnosed new work-related asthma in four spray foam insulation workers due to exposure to the PU spray foam. These cases, the first that the team was aware of, will be the
subject of an upcoming publication. The team is trying to learn as much as
possible about who is using these products and under what conditions through outreach activities. They have begun recruiting workers for their surveillance program, based on contacts made in their outreach activities. The surveillance program, which includes questionnaires,
spirometry (breathing test), and a blood test that can detect isocyanate exposure, may identify additional cases of occupational asthma or other health problems related to these PU products. Through responses to questionnaires, the team also expect to collect information about tasks, workflow and the types of products used so
as to identify the duration and form of potential skin and inhalational exposure to PU products,
about engineering controls that may be in place, and the extent to which the workers wear personal protective equipment from set-up through clean-up.
Research Partners: Small contractors, local unions, state health departments
Abstract:
Reactive isocyanate chemicals (R-N=C=O), the essential cross-linker for producing polyurethane (PU), are well-known sensitizers and one of the most common causes of occupational asthma, with methylene bisphenyl isocyanate (MDI) now the dominant isocyanate used. The construction industry has become the largest market for isocyanates in North America, with tremendous growth in the use of isocyanate- containing end-use products such as PU foam insulation, roofing materials, coatings, and adhesives. Despite the now widespread use of such end-user PU products in construction, there is a paucity of published information regarding the nature and extent of isocyanate respiratory and skin exposures among workers in this industry, and even more limited data on the associated health risks or effectiveness of different strategies (e.g. work practices, PPE, other controls) to reduce such exposures.
To address these research needs and prevent health effects of isocyanate exposures in construction workers we propose to conduct a series of field and intervention studies, with the following Specific Aims:
Aim 1) Assess the risk of respiratory and skin isocyanate exposures for different PU products and tasks in the construction industry, focusing on the most widely used products with potential isocyanate exposure risks, especially skin exposure.
Aim 2) Develop and implement health and exposure surveillance program for construction workers who work with or around PU products.
Aim 3) Using information from Aims 1 & 2, design, implement and evaluate an integrated intervention program to reduce isocyanate exposures in construction workers.
Aim 4) Disseminate information on the hazards of PU materials and preventive strategies to construction workers and the construction industry, based on knowledge gained from Aims 1-3.
