Advances in Construction and Confined Space Safety

Advances in Construction and Confined Space Safety

Monday, June 1, 2015, 10:30 AM - 12:50 PM

CS-105-01 ​​​Personal and Area Monitoring for Airborne Concentrations of Methylene Diphenyl Diisocyanate (MDI) and 2-Ethylhexanoic Acid (EHA) during and after Application of Low Pressure Polyurethane Foam Insulation in a Residential Crawlspace

J. Cikalo, Dow Chemical Company, Midland, MI

Situation/Problem: The objective of the study was to determine personal exposures and area concentrations of Methylene Diphenyl Diisocyanate (MDI) and catalyst during and after application of a closed cell spray polyurethane formulation to the rim joist of a residential crawl space.

Resolution: Industrial hygiene air monitoring was conducted using two different ventilation rates during two applications of spray polyurethane foam insulation in the crawl space of a residential home as a part of a product stewardship program. The crawl space was isolated from the other areas of the home by using a temporary barrier and ensuring that a separate source of makeup air was available. EPA and Center for the Polyurethanes Industry (CPI) Ventilation Guidance for Spray Polyurethane Foam Application, as well as the International Building code (IBC 2603.4) and International Residential code (IRC R316.4) principles were incorporated in the study.

Results: MDI monitoring results were 16 ppb for each of the two personal samples while area samples ranged from 1.7 - 2.2 ppb during spraying. One hour after spraying, area samples for MDI were less than the detection limit of 0. 4 ppb. The results of area samples for EHA were less than the detection limit of 0.2 mg/m3 during spraying and at one hour after spraying.

Lessons Learned: The results of the study will be used to enhance product stewardship practices associated with re-occupancy times following the application of low pressure spray foams. As per CPI (www.SprayPolyurethane.Org), some manufacturers recommend a one hour re-occupancy time following an interior two-component, low-pressure Spray Polyurethane Foam (SPF) kit application.

CS-105-02 ANSI A10.49- The Control of Chemical Hazards in Construction

M. Gillen, Retired from NIOSH, Washington, D.C.; S. Schneider, Laborers’ Health & Safety Fund, Washington, D.C.

Situation/Problem: Health hazards have always taken a backseat to safety in construction. Most ANSI standards and OSHA standards address construction safety issues like fall prevention, even though far more construction workers are estimated to die from exposures to health hazards than from accidents.

Resolution: Over the past few years the ANSI A10 committee which drafts voluntary standards for the construction and demolition industry decided to tackle this problem and develop a standard to help contractors address exposures to chemical hazards on their jobsites. The standard was finally completed in 2014 and affirmed by the A10 committee and ANSI. The standard combines control banding and pre-job planning approaches to help make it accessible to small and medium sized employers. Toxicity ratings are obtained using Safety Data Sheet (SDS). Hazard ratings and exposure potential are derived from various tables based on how substances will be used relying on known exposure factors (like the degree of enclosure). These ratings are then combined to determine the type of plan needed to control exposures: a basic plan for relatively low exposure and toxicity hazards, an intermediate plan developed by a “chemical hazard competent person” for more toxic materials with higher exposure potentials or an advanced plan developed by a qualified person (industrial hygienist) for the most highly toxic and high exposure situations. A separate similar analysis is done for task-generated exposures from existing materials on the site (e.g. renovation and demolition work).

Results: This presentation will review the new standard and discuss its development. It is hoped that this standard will help contractors take a closer look at chemical hazards in their worksites and move them to reduce exposures and risk of disease.

Lessons Learned: Health hazards in construction must be addressed in new ways such as voluntary (ANSI) standards.

SR-105-03 An Evaluation of Commercially Available Portable Local Exhaust Ventilation for Welding Fumes in Construction: The Epilogue

J. Meeker, University of Michigan, Ann Arbor, MI; P. Susi, CPWR, Silver Spring, MD

Objective: Welding is an important and pervasive process in construction. Overexposure to welding fumes and various toxic constituents among construction workers has been documented. However, use of engineering controls in this industry is still not common. Our objective was to identify commercially available, portable, local exhaust ventilation (LEV) systems viewed considered viable by end-users (contractors and welders) and to evaluate their effectiveness. In previous years, we described the results of our first two evaluations. Here we present the results of the third evaluation and summarize and compare all three systems tested.

Methods: As part of a larger project, an “Adoption of Innovations to Minimize (AIMS) Exposure to Dust and Fumes in Construction (AIMs)”, we assembled an industry partnership to select three commercially available, portable LEV units for welding fumes from among ten identified by researchers. Welding fume control effectiveness for both stainless steel (specifically hexavalent chromium [Cr VI], manganese [Mn] and nickel [Ni]) and carbon steel (specifically Mn and iron [Fe]) was assessed in separate randomized trials. Control vs. no control trial order was randomized to prevent systematic bias due to carryover exposures from one run to the next and other potential biases that might influence exposure levels. Static pressure was measured between each of the LEV-controlled trials several duct diameters downstream from the hood to assess air flow loss over time due to filter loading.

Results: We used the criteria of a 50% reduction in metal fume exposures or a reduction to below the most current or relevant occupational exposure limit to determine effectiveness. All of the systems tested met our criteria for effectiveness using these criteria. However, neither reductions in concentrations of Cr VI and other metals (Fe and Ni) during stainless steel welding nor reductions in Fe during carbon steel welding were statistically significant. Air flow based on hood static pressure measurements ranged from 112 to 158 CFM.

Conclusions: Effective LEV systems for welding fumes that are portable and practical for construction are commercially available. While HEPA filtration has been associated with reduced LEV air flow in extremely dusty construction operations, our data show that HEPA filtration for welding fumes is desirable and does not substantially reduce air flow.

CS-105-04 Think and Act Locally: Promoting Use of Engineering Controls in Construction at the Municipal Level

P. Susi, CPWR, Marlton, NJ; M. Goldberg, City University of New York, Emeritus, New York, NY; M. Weinstein, Florida International University, Miami, FL

Situation/Problem: Masonry restoration work, and specifically tuckpointing, is associated with very high silica exposures. More than half of exposure measurements collected by OSHA during tuckpointing were greater than twice the National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL) for respirable silica (US DOL, 2009). Despite high exposures, engineering controls for tuckpointing are still not often used. Although a proposed OSHA silica standard was published in 2013, a final standard is still pending. Here we examine increased use of local exhaust ventilation (LEV) for tuckpointing in Chicago some 15 years or more before a final standard is likely to be published.

Resolution: We conducted a case study to determine why and how use of LEV became more common for tuckpointing operations in Chicago. Key informants were interviewed, including a former OSHA area director, union leaders, and contractors. In addition, we reviewed archival data including municipal codes, specifications, training materials, articles and presentations describing and analyzing the use of LEV during tuckpointing.

Results: Four groups played key roles in the adoption of LEV in the Chicago: federal OSHA, local government agencies (both regulators and major users of construction services), Tuck Pointers Local 52, and local masonry contractors. They were motivated by concerns for occupational, public and environmental health. Major reasons for use of LEV in Chicago were: 1) concern for worker health among OSHA, local unions and their signatory contractors; 2) increased regulation and enforcement at both the local and federal levels; 3) owners’ mandates that required use of LEV; and 4) the need to minimize dust complaints from building occupants and the resulting work stoppages.

Lessons Learned: Beyond rule-making, OSHA may serve as an important catalyst in making an industry aware of a hazard and the means to control that hazard. However, local forces, both regulatory and market-based, may in some cases change industry practice more quickly and completely. The joint efforts of building trades unions, contractors and OSHA proved effective in addressing a pervasive hazard such as silica with effective and practical measures. Lessons learned in Chicago may inform efforts in other metropolitan areas where use of LEV for tuckpointing is less common.

CS-105-05 Confined Spaces in Residential Buildings

P. Bergholz, AMEC, Burnaby, BC, Canada

Situation/Problem: A property owner/manager did not have a complete confined space program and inventory along with hazard assessment (HA) and entry procedure (EP) documents for all potential spaces. The property manager owns and or maintains upwards of 9,000 buildings, towers, low rise apartment buildings, condominiums and detached houses in the province of BC. As a result of an incomplete inventory, not all building managers were aware of potential confined spaces on the properties. Additionally, due to geography of some of the properties, the accessibility of gas detectors and rescue resources were also limited.

Resolution: We were requested by the property owner/manager to update their program and inventory of confined spaces and prepare confined space HA and EP for residential buildings present throughout BC.

Results: Of the 62 buildings that were inspected for confined spaces, 115 confined spaces were viewed, assessed and grouped together into a total of 8 similar type spaces (e.g., crawlspaces, sumps, etc.). Hazard assessments and EPs were completed for these grouped / similar type spaces. Training was also provided to a large number of employees. Of the non-confined spaces viewed, many observed spaces (e.g., crawlspaces) bordered on whether or not they meet the definition of a confined space according to local regulations. For precautionary measures, a HA and EP was prepared for non-confined crawlspaces which did not meet the classification of a confined space (the most common non-confined space entered). Controls were implemented for these non-confined spaces such as gas testing and ventilation, and were utilized in a similar fashion, but to a lesser extent. Upon completion of the entire program, the property manager/owner implemented an online system to upload permits, and HA and EP for any spaces located in the inventory.

Lessons Learned: Implementing controls to mitigate hazards inside confined spaces or even non-confined spaces (availability of gas detectors and confined space rescue services) can be problematic for large property manager/owners with properties existing over a large geographical area. Confined spaces were observed in several newly built residential buildings, which highlights the need for input from an industrial hygienist at the design stage of buildings, whenever possible. As a result of our work to date, there have been no minor/severe injuries known to have occurred during confined space entries.

CS-105-06 Ventilation for Painting in Enclosed Spaces

D. Chute, Atrium Environmental Health and Safety Services, LLC, Reston, VA

Situation/Problem: Shipboard painting is often done in enclosed spaces. This work is difficult to ventilate for effective control of visibility, flammability and health hazards due to irregular spaces, limited access and egress and the distance between painting work and a satisfactory staging area for fans and blowers. There is a need to evaluate and control the effect of these variables under current work conditions.

Resolution: This work included a series of air monitoring surveys, ventilation airflow measurements and data collection in four shipyards. The goal of this data collection and analysis was to fill information gaps and prepare qualified estimation guidelines for ventilation required to effectively control of airborne contaminants during shipboard painting in enclosed spaces.

Results: Personal breathing zone and area air sampling was conducted for six different air contaminants including solvents, particulates and reactants. Six different coatings were applied during this testing, providing an excellent cross-section of the products currently used in the maritime industry. Brush and roll application was observed to be effectively ventilated with exhaust air drawn through flexible ductwork and discharged topside to the outdoors. Spray application was more problematic. Portable local exhaust ventilation was more effective for the control of breathing zone exposure than permanently-installed wall-mounted systems.

Lessons Learned: The participating shipyards were able to develop, demonstrate and apply specialized equipment, skills and methods to effectively install and operate fixed and temporary ventilation systems for painting in enclosed spaces. While the combination of temporary and fixed ventilation systems were observed to be generally effective, many key performance variables may change on a job to job or a daily basis. To respond to these changes, this work requires constant attention, adjustment, measurement and repair. Many dynamic variables could not be controlled consistently or predictably.

SR-105-07 Characterization of Exposure to Silica and Dust during Demolition and Crushing Operations in Construction, with and without Dust Controls

A. Bello, C. Mugford, S. Woskie, UMASS Lowell, Lowell, MA