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I ANZ 0004229 ENVIRONMENTAL SURVEY Corpus Christi Plant June 14-16, 1976 Prepared by: J. P. Sieverson Environmental Scientist Department of Environmental ASARCO Incorporated Salt Lake City, Utah Sciences Report Date: November 19, 1976 Distribution: CBWhite . HLMontague DHSoutar KWNelson AJGillespie, Jr./REDenham RCBeckstead EHHaug/WTSweat Dr.CHHine MOVarner*------------ ANZ 0004230 -1- ENVIRONMFNTAL SURVEY REPORT Corpus Christi Plant June 14-16, 1976 TABLE OF CONTENTS Page Executive Summary,........................................................................................ ii I. Operating Conditions ................................................................................ 1 II. Sampling Procedures ................................................................................... 1 A. Air ...................................................................................................................... 1 B. Noise ................................................................................................................ 2 III. Sampling Results ............................................................................................ 2 A. Air ..................................................................................................................... 2 1. Tape Samplers .................... 2 2. Personal Monitoring .................. 3 3. Ventilation ................................................................................. 6 B. Noise ............................................................................................ 6 1. Area Sound LevelMeasurements ............................... 6 2. Personal Noise Exposures .......................................... 7 3. Octave Band Analyses ...................................................... 9 IV. Comments .................................................................................................................... 10 A. Sulfide Unloading ........................................................................... 10 B. Sulfide Storage Bins ................................................................... 11 C. Zinc Debasing ....................................................................................... 11 D. Sulfide Cell House--Head Bar Buffing ................... 11 E. Neutral Cooling Tower ................................................................ 12 F. Cadmium Recovery ............................................................................... 12 G. Lead Pot ....................................................................................................... 12 H. Machine Shop ........................................................................................... 12 I. Laboratory ................................................................................................. 12 J. Yard Sweeper ........................................................................................... 13 K. Zinc Dust Units . ............................................................................... 13 L. Hearing Conservation .................................................................... 13 V. Recommendations ............................................................................................... 13 VI. Graphs .......................................................................................................................... 15 VII. Photographs ........................................................................................................... 16 ANZ 0004231 -11- EXECUTIVE SUMMARY Corpus Christi Plant June 14-16, 1976 Sampling data indicate that worker exposures to cadmium and total particulates exceed the current OSHA standards in the Sulfide Unloading and Sulfide Storage Bin areas. Audio Dosimeter data indicate that noise exposures in the Sulfide Unloading, Zinc Dust Screening, and Zinc Debasing areas exceeded the current OSHA noise standard (as did that of the Tennant sweeper operator). Other areas of the plant were in compliance with the applicable OSHA regulations. Sampling results also indicate that the air-supplied sandblasting helmet is not required for the headbar buffing operation in the Sulfide Cell House. A respirator and face shield is considered to be adequate for this operation. Recommendations include: Feasibility study of a ventil ation system for the Sulfide Unloading area? determination if a vibrator on the sulfide unloading hopper is feasible and curtailment of air lancing if such a device is installed; posting the Sulfide Unloading area as a "respirator required" area; use of hearing protection by the Tennant sweeper oper ator and employees in the Zinc Dust Screening, Sulfide Unloading and Zinc Debasing areas; and, replacement or reno vation of the laboratory hoods and ventilation systems. ANZ 0004-232 ENVIRONMENTAL SURVEY REPORT Corpus Christi Plant June 14-16, 1976 I. OPERATING CONDITIONS Operations were normal during the survey. Construction has been completed on the new dross plant since the last survey. The dross plant was operating normally. II. SAMPLING PROCEDURES* 1 2 3 A. Air: 1. One-hour sequential samples of fugitive emissions were collected with RAC Model G-2 tape samplers at the following locations: 1976 Date General Area________ Specific Area 6/16/76 Sulfide Unloading Workroom--on south wall 6/16/76 Sulfide Storage Bins Near Bin 66 The above samples were analyzed for lead and cadmium by atomic absorption spectrophotometry. 2. Individual dust and fume samples were collected with M.S.A. personal monitoring devices equipped with closed-face (plastic cover in place and inlet plug removed) Millipore filters (0.8 micron pore size). These samples were analyzed for lead, zinc, copper, and cadmium by atomic absorption spectrophotometry. Total particulate concentrations were found by weigh ing the filters before and after sampling. Arsenic levels were determined using a modified Gutzeit method with quantitation by a silver diethyl dithiocarbamate procedure. 3. Ventilation measurements were made with an Alnor Velometer, Series 6000-P. ANZ 0004-233 -2- B. Noise: 1. Area noise measurements were taken with a B&K Model 2205 Sound Level Meter using the "A" scale and "slow" response setting. The meter was calibrated with a standard noise source before and after each set of measurements. 2. Individual noise exposure data were collected using DuPont Permissible Audio Dosimeter, Model D-100, which measures noise exposures in terms of the present 90 dBA OSHA standard. A DuPont Audio Dosi meter Readout Model R150 was utilized to decode each dosimeter memory cell and produce a reading as a percentage of the current 90 dBA standard. 3. Octave band analyses were made around the zinc dust units. A GenRad Model 1565 BP Octave Band Analyzer was used. III. SAMPLING RESULTS A. Air: 1. Tape Samplers1 2 Depart ment Location Start ing Anal Time ysis Cone1 n. (mg/m^) Mean Max. Min. Sulfide Unloading Workroom (So. wall) 0750 6/16 Pb 0.17 0.41 0.07 Cd <0.01 <0.01 <0.01 Sulfide Near Bin 66 0745 Pb 0.11 0.40 0.02 Storage 6/16 Cd 0.23(1) 1.1 <0.01 Bins Percent Exceed ing OSHA Limit No of Hourly Samples Graph No. 14% 0% 71 7-- 13% 25% 8 (2) 8 (2) -- -- (1) Mean exceeds OSHA 8-hour time-weighted average. CURRENT STANDARDS: Pb =0.20 mg/m3 Cd (dust) = 0.20 mg/m3 PROPOSED STANDARDS: Pb =0.10 mg/m3 (2) The tape sampler advance mechanism must have malfunctioned during the sample period because 25 "hourly" spots were collected in the 8-hour period. However, only 8 visible spots were found on the tape. Therefore, these 8 spots were assumed to be full one-hour samples. All data are based on the 8 visible spots. ANZ 0004234 -3- 2. Personal Monitoring Department Sulfide Debasing (0.15% Pb) Employee Name and S.S. No. B. Nunez 466-52-0138 (No resp.) F. Flores 520-28-3417 (No resp.) M. Villareal 459-82-1778 (No resp.) R. Dieterich 457-96-7420 (No resp.) E. Munoz 458-72-4550 (No resp.) Job or Operation Machine Caster Machine Caster Caster Helper Caster Helper Trucker Samplinq 1976 Date & Time Shift (min.) Anal ysis Cone'n. (mq/m3) 6/15 374 Pb 0.005 D Zn 0.16 Tot.Pt. 1.3 6/15 368 Pb <0.005 D Zn 0.14 Tot.Pt. 1.2 6/15 370 Pb <0.005 D Zn 0.16 Tot.Pt. 1.4 6/15 370 Pb <0.006 D Zn 0.22 Tot.Pt. 1.7 6/15 363 Pb 0.006 D Zn 0.23 Tot.Pt. 1.9 Sulfide Cell House F. Sanchez 449-72-4488 (Wore airsupplied sand blasting helmet) Head Bar Buffing 6/15 348 Pb 0.03 D Zn 0.02 Cu 0.02 * Tot.Pt. 1.1 * Sampler worn outside sand blasting he lmet. J. Vallejo 449-16-7038 (No resp.) Barring out neutral cooling tubes 6/15 D 75 Pb <0.02 Zn <0.01 Cd <0.01 As <0.005 ( Tot.Pt. 3.6 Y. Vargas 464-14-3488 (No resp.) Barring out neutral cooling tubes 6/15 D 77 Pb <0.02 Zn 0.09 Cd <0.01 As <0.004 Tot.Pt. 9.5 ANZ 0004235 -4- 2. Personal Monitoring (con't.) Department Sulfide Cadmium Recovery Employee Name and S.S. No. P. Perez 465-24-9751 (No resp.) R. Ramirez 462-20-9219 (No resp.) Job or ODeration Cadmium Recovery Lead Man Cadmium 2nd Grade Operator Sampling 1976 Date & Time Shift (min.) Anal ysis Cone'n. (mg/m3) 6/15 270 Pb 0.009 D Cd 0.004 Tot.Pt. 1.8 6/15 270 Pb <0.005 D Cd 0.003 Tot.Pt. 1.6 Lead PotOxide Cell House E. Martinez 451-18-0848 (No resp.) J. Alaniz 465-24-7157 (No resp.) J. Silva 456-42-1228 (No resp.) Hand Caster 6/16 362 Pb 0.03 D Tot.Pt. 1.4 Caster Helper 6/16 356 Pb 0.01 D Tot.Pt. 1.2 Caster Helper 6/16 359 Pb 0.05 D Tot.Pt. 1.6 Laboratory H. Delgado 453-28-2519 (Resp. worn) Fire Assayer 6/16 D 99 Pb 0.11 (2) Tot.Pt. 3.8 Machine Shop P. Kunkel 452-56-8591 (No resp.) Lathing Carbon Barrels 6/16 435 Tot.Pt. 0.8 D Sulfide Storage R. Barrientes 453-18-3910 (Resp. use not observed) Hoistman * 6/16 360 Pb D Cd As Tot.Pt. * Hoisting until 9:30 a.m. , then worked around waste heat boiler. 0.01 0.01 0.002 3.2 ANZ 0004236 -5- 2. Personal Monitoring (con't.) Department Sulfide Unloading Employee Name and S. S . No. T. Perez (No. S.S.#) (Resp. worn) J. Ramirez (No. S.S.#) (Resp. worn) Job or Operation Sampling 1976 Date S Time Shift (min.) Anal ysis Cone'n. (mg/m3) Unloading 6/16 139 Pb 0.17 (2) DeCad Dust D Cd (dust) 0.18 As 0.003 Tot.Pt. 15. Unloading 6/16 136 Pb 0.02 DeCad Dust D Cd (dust) 0.75 (1) (31 As <0.003 Tot.Pt. 21. (1) Yard F. Ybarra 449-10-6079 (Resp. worn) F. Ybarra 449-10-6079 (Resp. worn) Sweeper 6/15 301 Pb 0.27 (1) Operator D Zn 2.0 (Oxide res Cd 0.03 idue area) As 0.03 (2) Tot.Pt. 8.9 Sweeper Operator (General area) 6/16 466 Pb 0.16 (2) D. Cd 0.01 As 0.012 (2) Tot.Pt. 4.4 (1) Exceeds the OSHA 8-hour time-weighted average exposures. CURRENT STANDARDS: Pb ZnO (fume) Cd (dust) As Cu (dust) Total Part 0.20 mg/m3 5.0 mg/m3 0.20 mg/m3 0.50 mg/m^ 1.0 mg/m^ 15.0 mg/m3 (2) Exceeds PROPOSED OSHA standards. PROPOSED STANDARDS: Pb As 0.10 mg/m3 0.004 mg/m3 (3) Exceeds the current OSHA ceiling concentration (never to be exceeded in an 8-hour shift) . OSHA STANDARD: Cd (dust) = 0.6 mg/m3 ANZ 0004237 -6- 3. Ventilation Ventilation measurements of laboratory hoods. Hood Perchloric Hood 2 South Hoods 2 West Hoods 4 East Hoods Velocity (fpm) <50 100 110 <50 Minimum acceptable face velocity = 100-150 fpm B. Noise: 1. Area Sound Level Measurements: Area Location Noise Level (dBA) Dross Mixing Plant Near electric motor for mixer 94 Sulfide Unloading Working platform with car vibrator ON 108 Inside work room with car vibrator ON 88 Inside work room with car vibrator OFF 68 OSHA Permissible Noise Exposure Duration Per Day (Hrs,/Min.) 4/36 0/40 8/0 8/0 ANZ 0004238 2, Personal Noise Exposures -7- Depart ment Employee Name and S.S. No. Job Title Sampling 1976 Date & Time Shift (min.) Dosimeter(D Readout (Percent) 8-hour ^ Adj usted Exposure (Percent) 115 dBA Exceeded? Sulfide Cell House F. Sanchez 449-72-4488 (Wore airsupplied sandblasting helmet) Head Bar Buffing 6/15 D 348 1 1 No Yard F. Ybarra 449-10-6079 Sweeper Operator 6/16 D 466 114 117<5) No Sulfide Storage Bins R. Barrientes Hoistman * 453-18-3910 6/16 D 360 22 * Hoisting until 9:30 a.m. then worked around waste heat boiler. Zinc Dust Units H. Williams (No S.S. #) #1 Unit Operator * 6/16 D 412 155 * Working around zinc dust unit for 230 minutes, then cutting metal for 115 minutes. 29 No 181(4) Yes (3) Zinc M. Villareal Debasing 459-82-1778 Casting, Skimming, Truck Op. R. Dieterich 457-96-7420 Stacking 6/16 D 6/16 D 417 410 91 15 9 kD CO 105(5) Yes<3> Yes(3) NOTE: See next page for footnotes. AN2 0004239 -8- Footnotes for Personal Hoise Exposure (1) Readout based on elapsed sampling time. (2) The 8-hour adjusted readout is an extrapolation of the original dosimeter reading. This extrapolation assumes that the employee will be exposed to the same noise level during the remainder of the shift when the dosimeter is not worn. (3) The OSHA noise standard does not allow employees to be exposed to sound levels greater than 115 dBA. However, experience to date shows that most dosimeter measurements greater than 115 dBA are the result of employee mischief, i.e, shouting into the microphone of the dosimeter. Therefore, these data must be interpreted with caution. (4) Dosimeter readouts greater than 100% indicate a violation of the OSHA noise standard. However, the accuraty of the dosimeter (as specified by A.N.S.I. SI.4-1971) is +. 2 dBA which translates to an upper confidence limit of 133%. Therefore only readings greater them 133% are positive violations of the OSHA noise standard. (5) Readings from 75% to 133% fall within the dosimeter calibration limits and may be violations of the OSHA standard. ANZ 0004240 3. Octave Band Analyses a. Location: No. 1 Zinc Dust Unit (On Operator's Platform) -9- Sound P ressure Level Sound P ressure Level b. Location: No. 2 Zinc Dust Unit (On Operator's Platform) ANZ 0004241 c. Location: Zinc Dust Hummer Screens -10- Sound P ressure Level Octave Band Center Frequency Hz IV. COMMENTS A. Sulfide Unloading: The sampling data show that workmen unloading railroad cars of Columbus DeCad dust were exposed to total particu late concentrations and airborne cadmium levels exceeding the current OSHA standards. One employee's exposure to cadmium dust was above the OSHA ceiling limit (which is never to be exceeded in an 8-hour period). These samples were taken on a particularly clear day with winds blowing dust away from the unloading area. Although respirator use was good, a ventilation system for the unloading area should be investigated. The use of air lances (to prevent bridging of the dust) should be curtailed if a different mechanism, such as a vibrator or thumper, can be installed. The unloading area should be posted as an area where "Respirators Are Required During Unloading". ANZ 0004242 -11- The tape sample data indicate that the unloading work room was contaminated with airborne lead. The low cadmin levels and favorable winds suggest the airborne lead did not come from the DeCad dust being unloaded. No other source of dust was apparent. Dust may leak into the workroom from the storage bins and should be investigated The workroom floor and walk should be checked and sealed if necessary. More air samples should be collected to determine the source of the airborne lead. The car vibrator is quite noisy and employees working around the area were noted to wear hearing protection when the vibrator is used. This is a good work practice that should continue to be encouraged. Emphasis should continue to be placed on the ASARCO Lead and Cadmium Hygiene Programs for the unloading employees. B. Sulfide Storage Bins The front end loader operator should wear a respirator in the bin area. A "Jesse James respirator" (bandana) was observed during the survey. Safety personnel have made an effort to reduce the use of bandanas for respir ators. This particular area has a potential exposure to metals much more toxic than zinc and therefore should be checked frequently to insure proper respirator use. This employee should also be included in the Lead and Cadmium Hygiene Programs, C. Zinc Debasing: The air sampling results indicate low levels of airborne lead around this operation. The alloy was 0.15% Pb during the survey; however, the lead content can go to 0.9% Pb. No exposure problems are anticipated and pre sent work practices are acceptable. Two audio dosimeters worn by employees show excessive exposure to noise. The noise sources are probably the zinc dust units nearby, wind noise from the cooling fans, and impact noise from slacking. Employees should wear hearing protection. The heat in this area may preclude the use of muffs, but ear plugs should be acceptable. Disposable plugs, such as those manufactured by E.A.R. or 3M Company, may be good for this application. D. Sulfide Cell House - Head Bar Buffing: The sampling results show that the air-supplied sand blasting helmet is not required. A respirator and face ANZ 0004243 -11- The tape sample data indicate that the unloading work room was contaminated with airborne lead. The low cadmium levels and favorable winds suggest the airborne lead did not come from the DeCad dust being unloaded. No other source of dust was apparent. Dust may leak into the workroom from the storage bins and should be investigated. The workroom floor and walk should be checked and sealed if necessary. More air samples should be collected to determine the source of the airborne lead. The car vibrator is quite noisy and employees working around the area were noted to wear hearing protection when the vibrator is used. This is a good work practice that should continue to be encouraged. Emphasis should continue to be placed on the ASARCO Lead and Cadmium Hygiene Programs for the unloading employees. B. Sulfide Storage Bins The front end loader operator should wear a respirator in the bin area. A "Jesse James respirator" (bandana) was observed during the survey. Safety personnel have made an effort to reduce the use of bandanas for respir ators. This particular area has a potential exposure to metals much more toxic than zinc and therefore should be checked frequently to insure proper respirator use. This employee should also be included in the Lead and Cadmium Hygiene Programs, C. Zinc Debasing: The air sampling results indicate low levels of airborne lead around this operation. The alloy was 0.15% Pb during the survey; however, the lead content can go to 0.9% Pb. No exposure problems are anticipated and pre sent work practices are acceptable. Two audio dosimeters worn by employees show excessive exposure to noise. The noise sources are probably the zinc dust units nearby, wind noise from the cooling fans, and impact noise from slacking. Employees should wear hearing protection. The heat in this area may preclude the use of muffs, but ear plugs should be acceptable. Disposable plugs, such as those manufactured by E.A.R. or 3M Company, may be good for this application. D. Sulfide Cell House - Head Bar Buffing: The sampling results show that the air-supplied sand blasting helmet is not required. A respirator and face ANZ 0004244 -12- shield would be adequate. However, the use of the helmet is no problem (other than maintenance of the helmet and air supply) and substitution of a respirator and face shield is a matter of choice. E. Neutral Cooling Tower: Barring out the cooling tower was a special job observed during the survey. The sampling results indicate that present work practices are acceptable. F. Cadmium Recovery: This area had very low metal exposures (as expected) and supervisors and workmen should be congratulated on the clean operation. G. Lead Pot: This operation also had low airborne lead concentrations indicating that the existing controls are adequate. H. Machine Shop: The lathing of carbon barrels results in low levels of total particulate which do not constitute a recognized problem. I. Laboratory: 1. Fire Assay: The lab had recently installed an electric furnace for fire assay work. The air sample shows a lead concentration in compliance with the existing OSHA standard, but above the proposed OSHA standard. Res pirator use was good so actual employee exposure should be low. However, a hood over the furnace to collect fugitive emissions (especially when the door is open) is recommended. 2. Ventilation System: The various hoods in the laboratory have face velo cities which vary from marginal to inadequate. New hoods and a new ventilation system are needed and have been repeatedly recommended. ANZ 0004245 -13- J. Yard Sweeper: The sweeper operator was exposed to airborne lead in excess of the OSHA standard when he was working around the oxide residue area. Proper respirator use should continue to be stressed. In addition, the sweeper oper ator should wear ear plugs. A better muffler on the Tennant sweeper might reduce the operator's exposure to within the OSHA limit. K. Zinc Dust Units: The audio dosimeter results show that men working around the Zinc Dust units are exposed at levels exceeding the OSHA noise standard. The octave band analyses suggest that the zinc hummer screens are the primary noise source and should be controlled first. Vibration dampners and an enclosure might prove helpful. L. Hearing Conservation: Annual audiograms are given to all employees. At present, however, no compensation for temporary threshold shift (TTS) is made. TTS is a reduction in hearing acuity caused by exposure to high noise levels. To minimize TTS, employees should spend sixteen hours in a quiet environment before an audiometric test. Audiometric exams should thus be scheduled to be given as soon as an employee reports for work. Advance notice is required so that the Foreman can make the necessary personnel adjustments and/or select the best day for the specific individual to be absent for the required time. If several people are to be tested on the same day, they may be selected from different departments or areas to minimize interference with production. The safety office stocks ear muffs and plugs, which are available to employees on request. Hearing protection was required only around the zinc dust units during the survey. The sampling data show that employees at sulfide unloading, zinc debasing, and yard sweeping should also be required to wear hearing protection. Signs stating that "Hearing Protection Is Required" should be posted at entrances to these areas. V. RECOMMENDATIONS A. A ventilation system for the sulfide unloading area should be investigated. ANZ 0004246 V -14- B. It should be determined if a vibrator or thumper on the sulfide unloading hopper is feasible. If this is prac-' tical and workable, the use of air lances should be curtailed after installation of such a device. C. Sulfide Unloading should be posted as a required respir ator area. D. The workroom at Sulfide Unloading should be checked for dust leaks and sealed, if needed. E. Hearing protection should be worn by employees at the Zinc Debasing and by employees operating the yard sweeper. Noise levels in the cab of the Tennant sweeper might be reduced if a better muffler is installed. F. Sulfide Unloading employees and the front end loader operator in the storage bins should continue to be en rolled in the ASARCO Lead Hygiene and Cadmium Hygiene Programs. The Tennant sweeper operator should also be in the Lead Hygiene Program, G. A hood over the fire assay electric furnace in the Labor atory is recommended, but would not presently be required for compliance with the current OSHA lead standard. H. The laboratory hoods and ventilation system should be replaced or renovated and maintained properly to insure adequate face velocities. JPS/nrh Enel. J. P. Sieverson Environmental Scientist ANZ 0004247 A irb o rn e Lead (m g/m 3 ) i -15- Time of Day ANZ 0004248 1 -16- SULFIDE UNLOADING AREA Employee is using an air lance to move dust down the bin. Replacement of the air lances with a bin vibrator or thumper is recommended. ANZ 0004249  This unit was being cleaned during the survey. Airborne dust and metal levels were well below OSHA standards. ANZ 0004250