The “Prototype SPF spraying booth” reduces exposure to Spray Polyurethane Foam (SPF) by separating the application zone from other parts of the building.
Hazard Analysis — Exposure to spray polyurethane foam (SPF) chemicals
Problem:
Workers that install and apply fire stop products may face hazards from exposure to spray polyurethane foam (spf) chemicals.Risk Description:
Using any chemical on construction job sites, especially in closed projects like buildings, could adversely affect workers' health. Workers can be exposed to SPF vapors and mist during spray application and also SPF dust when trimming, cutting, and scraping foam that has cured.
SPF particles can spread to other areas of a building, away from the application zone, and expose workers not using appropriate personal protective equipment (PPE). Exposure to SPF chemicals can cause serious health problems, including permanent lung damage and asthma, a potentially life-threatening disease. Workers affected by SPF exposure are often forced to leave their jobs to prevent worsening of respiratory symptoms.
Assessment Info:
To assess the risk of SPF exposure, one first needs to investigate the possible exposure routes. The United States Environmental Protection Agency (EPA) has provided a list of such routes to emphasize the need to acquire appropriate personal protective equipment while working with SPF products (https://www.epa.gov/saferchoice/potential-chemical-exposures-spray-polyurethane-foam). One need to note that the exposure can occur during and after application. The following three routes are most relevant to construction workers:
- Vapors and aerosols: generated by spray application, these vapors can exceed OSHA’s exposure limits and therefore need skin, eye, and respiratory protection. If not isolated, vapors and aerosols can spread through the building and remain there until a complete ventilation is performed.
- Dust: Produced during cutting and trimming of applied SPFs, dust contains hazardous chemicals that can remain in the building if not ventilated thoroughly.
- Heat-generating processes: Several common construction tasks (e.g., welding, brazing, soldering, treatment with a heat gun, hot scissors) could produce enough heat (150ºC to 180ºC) to start non-flaming degradation of polyurethane products and create toxic smoke consisting of carbon dioxide, carbon monoxide, isocyanates, hydrocarbons, etc. Workers exposed to these chemicals may suffer irritation of the eyes, dizziness, headaches, respiratory tract etc. This route requires more attention as it may make no obvious sign. Therefore, even after the foam is cured, maintenance workers such as electricians should not heat or grind spray foam.
To assess the risk level and exposure hazards of SPF products, the American Society for Testing and Materials (ASTM) international has developed several standards (D7859-19 and D8142-17) and work items (WK40292, WK58354, WK58355, and WK58356) to determine the levels of emissions from SPF products in different conditions. For instance, WK40292 (i.e., new test method for determination of vapor-phase organic compounds emitted from SPF using sorbent tubes analyzed by thermal desorption gas chromatography and mass spectrometry) is developed particularly for measuring emissions from specimens such as individual, volatile, and semi-volatile organic chemicals in chambers. WK58354, however, extends these methods to include more realistic conditions in spray booths that can be used in construction sites. These tests should be conducted by certified testing labs. Using a different methodology, WK58356 aims to assess the chemical emissions using a mathematical model that takes several input parameters. The model also could be used in prioritizing chemicals for future risk assessment studies.
To identify the hazardous parts of the job sites, OSHA has designed a specific hazard communication standard (HCS) for chemical used in workplaces. Figure 1 shows such pictograms that can be used in construction sites.
Figure 1 – OSHA HCS pictograms and hazards
Other than using these standards, one general assessment tool is to account for the ‘curing’ time when using SPF products. The manufacturer should be contacted to determine the re-entry time; this time can vary between 8 to 24 hours for one-component SPF and 23-72 hours for two-component SPF (https://www.buildinggreen.com/blog/epa-raises-health-concerns-spray-foam-insulation).
Regulations & Standards:
Regulations adopted by a state must be at least as protective as the corresponding federal standard. Work may also be subject to rules of other federal, state and local agencies. Even where there is no hazard specific standard, OSHA provides a general duty for the employer to provide a work site free from recognized hazards.
Federal OSHA Standards are enforced by the U.S. Department of Labor in 26 states. There are currently 22 states and jurisdictions operating complete State plans (covering both the private sector and state and local government employees) and 5 - Connecticut, Illinois, New Jersey, New York and the Virgin Islands - which cover public employees only. If you are working in one of those states or jurisdictions you should ensure that you are complying with their requirements.
Federal OSHA Standards are enforced by the U.S. Department of Labor in 26 states. There are currently 22 states and jurisdictions operating complete State plans (covering both the private sector and state and local government employees) and 5 - Connecticut, Illinois, New Jersey, New York and the Virgin Islands - which cover public employees only. If you are working in one of those states or jurisdictions you should ensure that you are complying with their requirements.
Contributors:
Behzad Esmaeili, Ph.D. - George Mason University
Pouya Gholizadeh - George Mason University
