On April 23, 2012, KCI industrial hygienist Josh Julius met with Mr. Ben Locke to discuss these and other potential exposures.

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1 E NGINEERS P LANNERS S CIENTISTS C ONSTRUCTION M ANAGERS 936 RIDGEBROOK ROAD SPARKS, MD (FAX) May 10, 2012 Ms. Denelle Bowser Environmental Health and Safety Manager Maryland Institute College of Art 1300 West Mount Royal Avenue Baltimore, Maryland Ref: Exposure Assessment Interdisciplinary Sculpture Studio Station Building Baltimore, MD KCI Job No Dear Ms. Bowser, KCI Technologies Inc. (KCI) is submitting the following letter report detailing the findings and recommendations from an assessment of potential exposures to airborne contaminants in the Interdisciplinary Sculpture Studio at the Maryland Institute College of Art (MICA). MICA retained KCI to assess exposures to airborne contaminants during tasks commonly performed by staff and students at the Studio. According to the Personal Protective Equipment Assessment provided by the Studio, MICA currently requires respiratory protection to be worn by staff while mixing silicacontaining mold shells, and during dusty operations involving sand, plaster and other bulk materials. On April 23, 2012, KCI industrial hygienist Josh Julius met with Mr. Ben Locke to discuss these and other potential exposures. Methods: On April 25, 2012, Mr. Julius conducted air sampling at the studio during a class. Over the course of the day, students and staff performed various welding and fabricating tasks, cast aluminum and bronze into molds, chipped away the ceramic molds from cast items, and mixed ceramic shell for casting. The sampling day was selected as one of the last days of the semester for students to work on projects, so the studio was busy throughout the day. Mr. Julius employed a combination of personal and area samples to capture worst-case exposure scenarios for students and staff engaged in or in the vicinity of activities with the potential for creating airborne contaminants. For the purposes of the assessment, activities were grouped together into four categories: General Tasks, Metal Fabrication, Foundry, and Shell Mixing. General Tasks: Throughout the 6-hour class period, students and staff welded, saw cut, torch cut and ground a variety of metals, chipped away ceramic molds, and performed other tasks. Two area samples were collected from the center of the shop area throughout the day. Both samples were collected on a 37mm pre-weighed PVC filter. Sample MFS-1 was collected using an aluminum cyclone to capture the only respirable fraction of airborne particulate and was analyzed for respirable dust using NIOSH method Sample MFS-2 was analyzed for total dust using NIOSH method KCI T ECHNOLOGIES, INC. Employee-Owned Since 1988

2 Ms. Denelle Bowser May 10, 2012 Page 2 Metal Fabrication Sample MFS-3 was a personal sample collected from the breathing zone of a student who was fabricating mild steel. Tasks included saw cutting, torch cutting, grinding and sanding and stick welding. The sample ran intermittently throughout the day as the student worked on fabrication. During periods when the student worked on other tasks, the sample was turned off. No local exhaust ventilation was used. The sample was collected on a 37mm mixed cellulose esther (MCE) filter and was analyzed for a 13-metal welding fume profile by NIOSH method Foundry Staff and students poured aluminum in the foundry in the morning and bronze in the afternoon. During both sessions, the metal was melted in the foundry. Students shoveled sand out of the pit, places molds in the pit and shoveled sand back around the molds. Sample MFS-4 was collected approximately 6 from the foundry during both casting periods. The sample was collected on a 37mm MCE filter and was analyzed for a 13-metal profile by NIOSH method Sample MFD-5 was collected in the vicinity of the sand pit as students shoveled sand. The sample was collected from the breathing zone of a student engaged in the shoveling for approximately 30 minutes in the morning and from approximately 8 feet downwind of the sand pit in the afternoon. The sample was collected using an aluminum cyclone and a 37mm pre-weighed PVC filter and was analyzed for crystalline silica (quartz, cristobalite and tridymite) by NIOSH method Shell Mixing Shell mixing consists of adding 40-pound bags of silica powder to a binder in a mixing drum. A hand drill with a mixing paddle is used to premix the shell until the slurry is of a smooth enough consistency that the mixing drum can turn. The process takes place inside of the shell mixing room, which is equipped with three local exhaust ventilation slot hoods. This task takes approximately minutes and is performed once or twice a month, typically by a MICA employee. The silica used in the shell mixture is a fused silica, as opposed to crystalline. Fused silica, while still associated with pulmonary disease, is less hazardous than crystalline silica, is analyzed by different methods and is subject to different regulatory limits. Sample MFS-6 was a personal sample that was collected from the breathing zone of a student who mixed the two batches of slurry. The entire process took approximately 45 minutes. After the mixing was done, the sample was left in the shop area to achieve the required air volume. The samples, along with field blanks, were sealed and sent under chain-of-custody to Galson Laboratories in East Syracuse, New York. Galson is accredited by the American Industrial Hygiene Association (AIHA#100324). Results: Results of the air samples and measurements are summarized in Tables 1 and 2. The laboratory analysis report and chain of custody form are included as Attachment A. Field notes are included as Attachment B. The sample results are compared to two different sets of criteria. The Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL), is a regulatory limit set by OSHA. Employers whose employees are exposed above the PEL must introduce some sort of control to reduce the concentration of contaminant to which employees are exposed. The American Council of Governmental Industrial Hygienists (ACGIH ) Threshold Limit Values KCI T ECHNOLOGIES, INC. Employee-Owned Since 1988

3 Ms. Denelle Bowser May 10, 2012 Page 3 (TLVs ) are health-based exposure limits below which a typical worker would not be expected to experience adverse health effects. All of the PELs and TLVs listed in Tables 1 and 2, unless noted as ceiling limits, are to be compared to 8-hour time-weighted averages (TWAs). The 8-hour TWA, the concentration of a contaminant averaged over an 8-hour period, can be calculated assuming a maximum time period for each exposure. Observations and discussions with Mr. Locke suggest that the maximum exposure for each task is as follows: General tasks 8 hours Metal fabrication 8 hours Handling sand in foundry 2 hours Shell mixing 1 hour The TWAs listed in Table 1 were calculated based on the assumption that the concentration of contaminant indicated by the sampling results is representative of the exposure throughout the maximum duration of each task. Table 1: Results of Dust and Silica Air Samples (mg/m 3 ) Sample ID Analyte Sampling Duration (min) Activities Performed Location Results (TWA) MFS-1 Respirable 360 General shop work, Middle of <0.11 Dust fabrication MFS-2 Total Dust 360 General shop work, fabrication MFS-5 Respirable Dust Shoveling sand in 105 Respirable for casting molds Silica MFS-6 Respirable Dust metal shop (<0.11) Middle of 0.58 metal shop (0.58) 0.45 Sand pit (0.11) (outside) (0.012) 98 Mixing shell slurry Personal 0.94 (0.19) OSHA PEL NOTES: < - denotes that the sample did not contain analyte above the laboratory s analytical limit of quantitation. 1. The PEL of 0.81 mg/m 3 is based on a silica content of 10%, and is derived from the formula: PEL = 10 mg/m 3 %SiO The PEL of 0.80 mg/m 3 assumes a fused silica content of 100%, and is derived from the formula PEL = 80 mg/m 3 %SiO 2 ACGIH TLV 10 NA 15 NA NA NA NA Table 2: Results of Metals Air Samples (mg/m 3 ) Analyte Sample MFS-3 Fabrication Sample MFS-4 Foundry OSHA PEL ACGIH TLV Aluminum < Antimony < < Beryllium < < Cadmium < < KCI T ECHNOLOGIES, INC. Employee-Owned Since 1988

4 Ms. Denelle Bowser May 10, 2012 Page 4 Table 2: Results of Metals Air Samples (mg/m 3 ) Analyte Sample MFS-3 Fabrication Sample MFS-4 Foundry OSHA PEL ACGIH TLV Chromium < < Cobalt < < Copper Iron Oxide Lead < < Manganese (C) 0.2 Nickel < Vanadium < < Zinc Oxide < NOTES: < - denotes that the sample did not contain analyte above the laboratory s analytical limit of quantitation. (C) denotes a ceiling limit. This is a limit not to be exceeded for any length of time. 1. TLV for iron oxide is for the respirable fraction 2. As vanadium pentoxide Conclusions: The results of the air sampling indicate that airborne concentrations of the contaminants of concern were below applicable OSHA PELs and ACGIH TLVs. Recommendations: KCI recommends that students and staff continue to be trained in hazards associated with products used in the interdisciplinary sculpture studio and be offered the use of voluntary respiratory protection, in accordance with 29CFR However, the air sampling results do not indicate that respiratory protection is required to meet OSHA regulations. KCI recommends that a qualitative exposure assessment be incorporated into the regular safety audits. The assessment should determine if controls are working properly, if students and staff are obeying policies and procedures, and if there have been significant changes to procedures, materials or durations of tasks that would indicate the need for additional air sampling. If you have any questions regarding this report, please contact me. Sincerely, KCI Technologies, Inc Josh Julius Certified Industrial Hygienist (410) cc: file M:\2012\ \REPORTS\MICA INTERDISCIPLINARY SCULPTURE STUDIO EXPOSURE ASSESSMENT.DOCX KCI T ECHNOLOGIES, INC. Employee-Owned Since 1988

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