Attachmnt 6 - Technical Exhibit - NEHC - TM6290 99-10 Rev 1.pdf

Navy Environmental Health Center Technical Manual NEHC–TM6290.99-10 Rev.1 (May 2002)

INDOOR FIRING RANGES

INDUSTRIAL HYGIENE

TECHNICAL GUIDE

NAVY ENVIRONMENTAL HEALTH CENTER

BUREAU OF MEDICINE AND SURGERY

Nancy.Owens Text Box DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited.

TLTorba Text Box Technical Exhibit 6

INDOOR FIRING RANGES

INDUSTRIAL HYGIENE

TECHNICAL GUIDE

Published By

NAVY ENVIRONMENTAL HEALTH CENTER

620 John Paul Jones Circle

Portsmouth, Virginia 23708-2197

Revision 1 May 2002

Navy Environmental Health Center Technical Manual NEHC-TM6290.99-10 Rev. 1

Contents

1.0 Introduction

1.1 Purpose

1.2 Use

1.3 Other technical assistance

2.0 Hazards

2.1 Components of ammunition

2.2 The firing/shooting process

2.3 Bullet impact

2.4 Lead

3.0 Design

3.1 Length

3.2 Firing lanes

3.3 Structure design and construction

3.4 Bullet stops (traps)

3.5 Selection and installation of bullet traps

3.6 Regular maintenance

3.7 Target retrieval systems

3.8 Shooting Booths

3.9 Rubber mats

3.10 Lighting

3.11 Alarms

4.0 Mechanical

4.1 Ventilation Systems

4.2 Air Distribution

4.3 Air flow

4.4 Intake and discharge of air

5.0 Evaluation

5.1 Physical and operational assessment

5.2 Ventilation assessment

5.3 Air sampling

5.4 Range cleaning

5.5 Hygiene

5.6 Surface contamination assessments

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6.0 Controls

6.1 Substitution

6.2 Ventilation systems

6.3 Maintenance

6.4 Administrative

7.0 Acceptance Testing

7.1 Background

7.2 Generic industrial hygiene acceptance test

Appendices

Appendix A - Health Considerations for Routine Range Use/Cleanup: Generic Standard

Operating Procedure for Training Type Indoor Small Arms Ranges

Appendix B - Wipe Sampling for Settled Lead-Contaminated Dust

Appendix C - Lead Removal Plan/Material Containing Lead Removal Plan

Appendix D - Indoor Firing Range Cleaning Guidance

Appendix E - Sources of Information

Appendix F - Industrial Hygiene Acceptance Test

Disclaimer: Mention of the name of any company or product or the depiction of engineering designs does not constitute endorsement by Navy Environmental Health Center or the Department of the Navy.

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1.0 Introduction

1.1 Purpose - This reference guide is intended to provide general information regarding indoor firing ranges (small arms ranges) to assist in recognizing, evaluating and controlling safety and health hazards. The contents are drawn from Federal regulations, Navy instructions, and other technical documents.

1.2 Use - This guide should be useful to range operators, industrial hygienists, safety professionals and technicians in performing range evaluations, understanding conditions that require additional expertise and developing operation and maintenance procedures.

1.2.1 This guide provides the following:

1.2.1.1 General hazard information,

1.2.1.2 General design and operation aspects,

1.2.1.3 Systems and equipment of industrial hygiene concern,

1.2.1.4 General discussion of ventilation design and evaluation,

1.2.1.5 Work practices and recommendations for controlling exposure to hazards and safe operation,

1.2.1.6 Other sources of information.

1.3 Technical assistance

1.3.1 For questions regarding this guide, users may contact Mr. John Bishop, CIH, Navy Environmental Health Center, Industrial Hygiene Directorate, (757) 953-0752, DSN 377-0752, e-mail john.bishop@med.navy.mil.

1.3.2 For engineering support, contact the Naval Facilities Engineering Command, Technical Centers of Expertise, Mr. Randy Jackson, P.E. at (757) 322-4316.

2.0 Hazards

2.1 Components of ammunition

2.1.1 The projectile or bullet is usually made of a dense material such as lead and may be covered or jacketed with a copper-zinc alloy. Some special purpose bullets may be made from metals other than lead. The bullet may be non-jacketed (totally exposed lead bullet) or totally or partially jacketed. Even in totally jacketed bullets, the base of the bullet may have exposed lead.

2.1.2 The casing contains the propellant and the primer. The casing is usually brass and most ranges will recover them for recycling. The propellant is the main charge and provides the expanding gas that propels the bullet. It is usually a mixture of nitrocellulose and nitroglycerin. The propellant is ignited by the primer which is an explosive. Common formulations of primers contain sensitive metallic salts and metallic nitrate compounds that serve as an oxidizer (fulminates of lead, including lead styphnate, and sometimes lead peroxide).

2.2 The firing/shooting process

2.2.1 When struck by the firing pin, the primer explodes, igniting the propellant.

The burning propellant can generate pressures of 18,000 to 20,000 pounds per square inch (psi) and may reach a temperature of 2000 degrees Fahrenheit. The expanding gas propels the bullet down the barrel.

2.2.2 The bore (inside diameter of the barrel) is scored with spiral groves called rifling. These grooves cause the bullet to spin as it is traveling down the barrel. A spinning bullet is more stable and resists tumbling as it travels through the air towards the target.

2.2.3 The velocity achieved is directly related to the amount of propellant in the charge. Pistol bullets accelerate to nearly the speed of sound. High powered pistol and rifle bullets reach speeds above the speed of sound.

2.3 Bullet impact

2.3.1 In an indoor range, the projectile will eventually require its energy to be absorbed. Bullets usually impact onto or into some type of bullet trap (see Section 3). On impact, the bullet may fragment in many directions. This is known as "backsplatter." Factors in the generation of backsplatter are the angle at which the projectile impacts the trap, the smoothness of the impacted surface and the impact velocity. The greater the energy of a bullet, the more likely the fragments will continue on their original path and not bounce back. Lower energy bullets (e.g., subsonic ammunition) produce the most pronounced backsplatter.

2.3.2 Backsplatter fragments projected back towards the shooter are called a ricochet. Ricochets should be rare in a properly designed range. Ricochets may also be caused by the type of target used. Hard targets such as bowling pins and metal targets (poppers) can increase the likelihood of ricochet. Improper ammunition used on the range may dent the bullet stop, increasing the chance of ricochet. Bullet strikes on structural components (target retrieval systems, electrical fixtures, etc.) can cause ricochets. Plate and pit traps in need of cleaning (many bullets in the trap) can increase ricochet.

2.3.3 Bullets that miss the target and trap can penetrate floors or ceilings of improperly designed or constructed ranges, thus posing a severe danger to surrounding areas.

2.4 Lead

2.4.1 Sources

2.4.1.1 Lead primers (fulminates) [lead staphynate or lead peroxide]

2.4.1.2 Projectiles (bullet)

2.4.1.3 Bullet stop (trap)

2.4.2 Exposure factors

2.4.2.1 During firing, hot gases from the propellant can vaporize lead in the bullet. Even with "full jacketed" bullets, lead may be vaporized if the base of the bullet is not jacketed. Rifling or misalignment of the barrel, cylinder, clips, or magazines may chip lead from the bullet.

2.4.2.2 As the bullet leaves the barrel, the hot expanding gases from the propellant and the primer will leave the muzzle in all directions (sideways). The expanding gases and the pressure shock can cause disturbances in the air around the breathing zone of the shooter. If ventilation is present, it may be difficult to capture and control all of the contaminants produced. With effective ventilation, lead particles are carried down range (toward the trap). Because of their density and the effect of gravity, lead particles will settle out of the air quickly, coating the surfaces immediately down range from the shooter with fine lead dust.

2.4.2.3 Lead particles (dust) may be inhaled by the shooters and range personnel during firing, maintenance and cleaning of the range. Lead dust will not penetrate the skin. However, contamination on hands, arms or the face may allow ingestion of lead during eating, drinking, smoking or applying of cosmetics if the skin is not adequately cleaned.

2.4.3 Exposure and Health considerations. Substance information regarding occupational exposure to lead and a summary of the key provisions of the Occupational Safety and Health Administration (OSHA) regulations are provided in 29 CFR 1910.1025.

2.4.4 Exposure limits. Exposure limits are set by OSHA and adopted by the Navy in OPNAVINST 5100.23 Series.

2.4.4.1 Permissible Exposure Limit (PEL). The PEL for an 8-hour time-weighted average (TWA) exposure to airborne lead is 50 micrograms per cubic meter (μg/m3) of air. For employee exposure of more than 8 hours in a workday, the PEL shall be determined by the following formula.

PEL (μg/m3) = 400__________ No. Hours Worked Per Day

2.4.4.2 Action Level (AL). The AL for an 8-hour TWA exposure to airborne lead is 30 μg/m3 (without regard to respirator use). Exposure to airborne lead at or above the AL, for more than 30 days per year, triggers biological monitoring and medical surveillance requirements.

2.4.5 Dust lead levels. There are no directly applicable established limits for occupational surface contamination (mass of lead per surface area). However, in a compliance instruction (CPL 2-2.58) for lead in the construction industry, OSHA has provided a level of acceptable lead loading (surface dust levels) for non-lead work areas (clean areas outside lead work areas, such as lunchrooms) of 200 μg/square foot (2152 μg/square meter or 21.52 μg/100 square centimeters). While not legally applicable, this serves as a useful guideline.

2.5 Other stressors.

2.5.1 Ammunition may contain other metals, such as barium and antimony.

2.5.2 The ignition of primers and propellants during firing can produce other toxic compounds. Ventilation systems that adequately control lead should also control exposures to any other toxic compounds generated. Other compounds that may be generated during firing:

2.5.2.1 Carbon monoxide. Carbon monoxide reduces the ability of blood to carry oxygen. Symptoms of over exposure include headache and nausea.

2.5.2.2 Oxides of nitrogen. Nitrogen oxides are irritating to the eyes and the respiratory system.

2.5.2.3 Organic compounds and unburned propellant. Other organic compounds may be generated. Of special concern is the unburned propellant that may accumulate down-range over a long period of time. This may create a fire hazard if the range is not cleaned properly and regularly. Unburned propellant may accumulate in porous surfaces or in crevices (concrete joints).

2.5.3 Noise. The discharge of weapons creates hazardous impulse noise levels.

In a firing range, the impulse noise may act differently when it reflects off of hard surfaces.

Repeated exposure to impulse noise greater than 140 decibels (dB) can cause significant hearing loss. The Navy permissible exposure limits (NPEL) and requirements for noise are presented in OPNAVINST 5100.23 Series, Chapter 18:

2.5.3.1 Greater than 84 decibels on the A-weighted scale (dB(A)) for frequencies of 20 to 16,000 Hertz (Hz)) for an 8-hour time-weighted average (TWA).

2.5.3.2 When TWA exposures are greater than 84 dB(A), activities shall include personnel in the Navy's Hearing Conservation Program.

2.5.3.3 For impact or impulse noise, the NPEL is 140 dB (peak) sound pressure level.

2.5.3.4 Noise reduction. Noise reduction in the range and outside the range require two different design considerations. Absorptive type acoustical surfacing can reduce the noise within the range. However, noise reduction within the range has trade-offs in the increased porosity of surfaces that can become contaminated with fine lead particles and the increased difficulty in cleaning such surfaces. Acoustical treatment behind the firing line is acceptable if it can be easily cleaned. Reflective surfaces in a range will reverberate noise during firing, extending the decay rate of the noise. Long decay rates (> 1 second) will require the industrial hygienist to treat the noise not only as impulse (peak pressure considerations) but as continuous noise also.

2.5.4 Eye hazards. Ricochets can be a significant eye hazard in indoor ranges.

Poorly maintained traps or misdirected shots can cause fragments to be thrown back toward the firing line.

3.0 Design. The proper design of an indoor range provides a facility that meets the purpose of conducting weapons training in a safe manner. Several documents are available to assist in the design of indoor firing ranges and are listed in the Bibliography section. The following are several design recommendations with cited references:

3.1 Length of range. Usually 50 to 100 feet from the firing line to the furthest target line. The standard length of new ranges is 84 feet 4 inches (CEHND 1110-18, Draft UFC 4-160- 01).

3.2 Firing lanes should be 5 feet wide (CEHND 1110-18) with a minimum of 4 feet wide (NGR 385-15, Draft UFC 4-160-01). The height should be 10 feet, but may need to be higher depending on the bullet stop design (CEHND 1110-18).

3.3 The structure design and construction must accommodate the weapons (ammunition) used and must prevent bullets from penetrating and exiting the walls.

Recommended materials and construction are discussed in CEHND 1110-18 and MIL-HDBK 1027/3 (soon to be retired and replaced with Draft UFC 4-160-01). From a health and safety perspective, the following interior surface criteria should be met:

3.3.1 Surfaces should be as smooth as possible with no protruding edges.

3.3.2 Smooth dense floor surface, easily cleanable, with no floor joints that can provide an impact edge. Carpets should be prohibited, as they collect lead dust and are difficult to clean.

3.3.3 Baffles must be installed to protect light fixtures, pipes or ceiling from misdirected shots. Baffles should be at 30 degree angles to the ceiling and constructed of steel plate based on the ammunition used. Baffles within 40 - 50 feet of the shooting line should be covered with splatter protection (material and thickness depends on weapon/ammunition used).

See CEHND 1110-1-18 (Draft UFC 4-160-01).

3.4 Bullet stops (traps). The purpose of the bullet stop is to absorb the energy of the bullet and to prevent the projectile or fragments escaping. There are several types of stops used in indoor ranges:

3.4.1 Plate and pit (Figure 1). The bullet stop consists of a plate of steel installed at a 45 degree angle. The thickness and hardness of the steel depend on the ammunition used (CEHND 1110-1-18). After striking the plate, the bullets are directed into a sand pit.

There must be at least 6 - 8 inches of sand depth in the pit. These traps are not recommended since they require a high level of maintenance. They must be cleaned by removing the bullets from the sand - a messy operation with high lead exposure potentials. Lack of cleaning may cause ricochet hazards if bullets entering the sand pit strike other bullets.

Figure 1 - A Plate and Pit Bullet Stop

3.4.2 Escalator bullet stop (Figure 2). The escalator bullet stop has sloping steel surfaces to guide the bullet into a location where the projectile's energy can dissipate safely. The bullet travels up the surface of the plate to either a "swirl" area or deceleration chamber. Due to friction or multiple impacts, the bullet loses energy, then falls into a tray for later collection.

Figure 2 - Escalator bullet stop

3.4.3 Venetian blind. Several impact plates are angled at approximately 35 degrees to direct the bullets downward into a deceleration chamber. The plates are set such that they have the appearance of a venetian blind. The leading edges are sharpened in order to split bullets that strike right on the edge. Maintenance is required to keep the edges sharp for proper operation.

3.4.4 Snail type. The snail bullet stop is basically a large scroll where the bullet enters and looses energy through friction as it spins around the scroll. A water bath may be present to remove fragments.

3.4.5 Rubber lamella. This bullet stop is made of strips of rubber in multiple rows suspended from the ceiling. A steel safety plate is installed behind. The bullet energy is absorbed in the rubber and the projectile remains mainly intact.

3.4.6 Granular rubber. A steel based chamber opened towards the firing line is filled with granular pieces of rubber. This acts like a berm to receive the fired projectiles. The bullets remain intact, which reduces lead fragments, dust and backsplatter. The bullets migrate down through the granulated rubber and can be removed from cleanout access points under the steel chamber. The granular rubber bullet traps can either be reclined or installed vertically with a rubber membrane to hold the rubber.

3.5 The selection and installation of bullet traps must be based on the facility, construction materials, space, and most importantly the weapons and ammunition used. Trap design, construction and materials may restrict the types of weapons and ammunition which may be used safely within the facility.

3.6 Regular maintenance must be performed on the bullet traps to prevent ricochets or penetration and to reduce the chance of fired bullets impacting collected bullets. Follow the cleaning procedures provided by the manufacturer for commercially installed traps.

3.7 Target retrieval systems are recommended to prevent shooters or range personnel from entering the area downrange of the firing line. This will reduce the chance of accidental shooting mishaps and tracking of lead contaminated dust to other areas of the range or to personal clothing. Target holders must not present a flat surface perpendicular to the line of fire.

Angled iron with the point facing the firing line is recommended to prevent ricochets.

3.7.1 The target should be retrieved by hand crank or a motorized mechanism.

3.7.2 The target height must be adjustable if firing will be conducted in prone, sitting, kneeling or standing positions.

3.7.3 The target should have a locking mechanism to keep the target from moving during firing.

3.7.4 Targets (based on lane positions) should not be positioned in line with seams or welds in the bullet stop.

3.7.5 Automatic turning target mechanisms are available with programming provisions for target exposure.

3.8 Shooting booths or partitions (Figure 3) may be installed between the firing positions to reduce the possibility of misdirected fire. The booths should be fixed to the floor and at least 6 feet high. They should not extend more than 6 inches down range from the firing line or extend more than 18 inches back (behind) the firing line to ensure unrestricted viewing by the range master or instructor. Although arm rests are common, partitioning off the lower portion of the booth is undesirable as it obstructs air flow.

Figure 3 - Shooting Booths

3.9 Rubber mats may be used for prone or kneeling firing positions. They should have tapered edges (to avoid tripping) and should be easily cleaned. Mats should be stored out of the way when not in use.

3.10 Lighting. Lighting design should provide uniform intensity and be free of glare without shadows.

3.10.1 Lighting behind the firing line should not interfere with the shooter's view down range. The lighting should be intense enough to avoid enlargement of the pupil, which reduces the shooter's visual acuity.

3.10.2 Down range lighting should be at least 85 – 100 foot-candles measured 4 feet above floor at target face and baffled (no direct lighting to the firing line and protected from misdirected shots) (Draft UFC 4-160-01).

3.10.3 Other lighting includes emergency lights for egress, "Range in Use" signs at the entrance and exit lights. Lighting behind the bullet trap should be at least 30 foot-candles during maintenance or cleaning.

3.11 Alarms. The range may be equipped with alarms either on the firing line (notification that a shooter has crossed the line) or for the ventilation (signaling that the ventilation is not operating or electrical interlocks with the lighting that will not activate unless the ventilation is on and functioning properly).

4.0 Mechanical. Mechanical aspects of an indoor range include ventilation, heating and air cleaning systems.

4.1 Ventilation Systems. Ventilation in a range controls exposure to lead and other contaminants. The supply and exhaust air system design is crucial to proper operation. To ensure proper operation, interlocks should be installed that require both the supply and exhaust fans to be running.

4.1.1 Exhaust. The exhaust system removes contaminated air from the range.

The exhaust flow rate determines the velocity of the air down the range but does not affect the air flow pattern at the firing line. Exhausting 3 - 7 percent more air than is supplied will maintain a slight negative pressure in the range. Ranges should be maintained under negative pressure of -0.04 + 0.02 inches water gauge. Because of the large volume of air being exhausted, energy recovery systems should be considered. Fans should be single speed and not multiple speed. Indicators (static or velocity pressure) for monitoring flow are a good idea to demonstrate proper operation of the exhaust system.

4.1.2 Supply air. The exhausted air flow must be made up by outside air. The distribution of the supply air is critical in determining the effectiveness of the ventilation system.

Supply air systems are designed to distribute air evenly across the width of the firing range. If not evenly distributed, air flow at the firing line will be turbulent, causing lead and other contaminants to be carried back into the shooter's breathing zone. Supply air should be introduced as far up range as possible.

4.2 Air distribution. The distribution of supply air should provide uniform, diffuse, non-turbulent air flow towards the firing line and a near laminar flow down range.

4.2.1 Perforated wall. A perforated rear wall (Figure 4) will provide uniform air distribution. A minimum of 15 feet distance is needed from the wall to the firing line. The system should maintain laminar flow of 50 - 75 feet per minute over the cross sectional area at the firing line. The minimum should be 50 feet per minute with a preference of 75 feet per minute. The system should provide 100% outside air. The perforated wall (sometimes known as an "air wall") should be designed to act as a plenum with approximately 6 - 10 percent free open area. This should evenly distribute the required flow at a pressure drop of 0.25 inches water gauge. The perforations should be sized to provide no more than 2000 feet per minute velocity through the holes, with a recommended velocity between 400 - 600 feet per minute. Hole diameters from 0.25 to 1 inch have been used effectively, with recommended diameters between

0.375 and 1 inch (3/8" - 1"). The perforated wall should extend the entire width and height of the range to distribute the supply air evenly. The plenum wall can be constructed of perforated hardboard, metal or clear plastic sheeting (polycarbonate/acrylic, etc.). Doors within the plenum are undesirable. Internal framing may interfere with air distribution.

Figure 4 - A perforated rear wall

4.2.2 Radial plenum (Figure 5). The radial plenum is a supply air system that has perforated metal half-round sections that are located in the upper back corner of the range. This radial plenum runs the entire width of the range. This system has been shown to be acceptable.

The system should still maintain laminar flow of 50 - 75 feet per minute over the cross sectional area at the firing line, with a minimum of 50 feet per minute and a preference of 75 feet per minute. The system should provide 100% outside air.

Figure 5 - Radial supply air plenum

4.2.3 Dampers/diffusers. Many ranges have supply air distribution systems using dampers or diffusers. These are least desirable since they produce jets of air that can produce turbulence at the firing line. If diffusers are present, they should be located on the back wall behind the shooters. Diffusers should be sized to produce no more than 400 feet per minute maximum velocity.

4.3 Air flow. Air flow across the firing line should be approximately 75 feet per minute with a minimum acceptable flow of 50 feet per minute. Air flow down range should be maintained at a minimum of 30 feet per minute and should be evenly distributed. The air should be exhausted at or behind the bullet stop. Some ranges are designed to have multiple exhaust points down range. The important feature is to maintain the laminar flow and desired velocities at the firing line. When a floor to ceiling and wall to wall supply distribution system is used, there should be no obstructions to the air flow between the plenum and the shooting station.

Exhausting the air past the bullet stop assists in controlling exposures during down range maintenance and cleanup.

4.4 Intake and discharge of air.

4.4.1 Powered make-up air systems are desirable. Supply air should be 100 percent outside air. Air intake should be located to avoid recirculation of the exhausted air.

Supply air may be heated. Depending on the outside air temperature and the size of the range (the needed volumetric flow), heating may not be cost effective. Range heating may be supplied by spot heaters at the firing line. Note that fans on spot heaters can disrupt air flows at the firing line. Gas fueled open fired heaters (no heat exchanger) can be installed in the supply air system.

They must be properly designed and maintained to reduce the possibility of high carbon monoxide levels within the range.

4.4.2 The exhaust discharge must be separated from the supply air intake. If the range is part of a larger building or adjacent to other buildings, the range exhaust should not be located where cross contamination can occur. Note prevailing wind patterns or building projections that may cause turbulence or eddy currents which can affect ventilation effectiveness.

4.4.3 Filtration of the exhausted air may be required by local requirements.

Provisions for increasing fan size to handle increased static pressures must be considered if exhaust filtration is retrofitted. A pressure drop (magnehelic/incline manometer) gauge across the filter is recommended to indicate when filter changes are required.

5.0 Evaluation. From a safety and health perspective, it is necessary to determine if an indoor range is operating properly. There are a few important steps that can be taken to properly evaluate an indoor range. The range must be evaluated from two perspectives--the physical/mechanical and the operational. The first includes the facility design, construction and the mechanical systems used in the facility. The second focuses on how the range is operated (the interaction of the occupants, weapons and ammunition with the facility).

5.1 Physical and operational assessment. Conduct a walk-through assessment of the facility and look for the desired design traits discussed in section 3. Note how the facility is maintained and operated. Gather information on the range's construction, layout, maintenance, listed weapon(s) used in the range, training content, expected number of shooters, frequency of use and typical expended rounds used. This information will be needed to conduct the operational risk assessment and to classify the range (see Appendix A).

5.2 Ventilation assessment. A properly designed and operating ventilation system is necessary to control exposures to shooters/instructors.

5.2.1 Smoke test. Using either a smoke tube or smoke candle, observe airflow currents and patterns throughout the range. This should identify disturbances and direction of airflow. Unnecessary personnel should not be present in the range or near the supply air plenum during the assessment. Prior to activating the tube or candle, ensure that the ventilation system is on and operating. If a smoke candle is used, a coffee can with some type of a handle fabricated (pliers) should be used to handle the candle. At the firing line, smoke test each firing station (booth). Test from the floor to about 6 foot level. Observe the smoke pattern. The smoke should move down range and demonstrate laminar flow. Document unusual smoke patterns or where smoke swirls and returns to the shooter's position. Eddies or swirls near the floor, or other obstructions are a concern and should be noted. If turbulence is observed, air velocities may be high in that area. Note that air velocity measurements conducted later in this area may not truly indicate the direction of the flow (turbulence and eddies may have flow directions other than down range but will be reflected only as a measured value). Conduct additional smoke measurements down range to ensure adequate air velocities and patterns are maintained down range towards the bullet stop. Note that many ranges were designed to have multiple exhaust points down range that will affect the smoke patterns.

5.2.2 Measure the cross sectional area for the range and calculate the necessary volumetric air flow. Measure the ceiling height and width of the range at the firing line.

5.2.3 Measure the ventilation. At the firing line, place the probe (or a grid meter if available) so that it is perpendicular to the floor at the firing line. Make sure no unnecessary personnel are present or near the supply air plenum during the assessment. Take three measurements at the same level in three locations from the floor: approximately 1 foot (prone level firing); approximately 3 feet (kneeling position); and approximately 5 feet (standing position). This will result in 9 readings for each firing position (or three grid meter readings).

Average the 9 (or 3) readings and apply to the design criteria (50 - 75 feet per minute, with preference for 75 feet per minute). Optional measurements may be conducted down range at the 1, 3 and 5 foot high levels to ensure adequate air velocities are maintained (30 - 50 feet per minute). This can be conducted at 15 to 20 foot intervals. Again note that many ranges were designed to have multiple exhaust points down range.

5.2.4 Static pressure measurements. Since it is desirable to have the range under negative pressure related to other occupied spaces, static pressure measurements should be conducted in one of two ways. A manometer or magnahelic gauge can be used to check the pressure in relation to areas outside the range. A hose can be placed outside the door (careful not to crimp) with at least 6 inches of the hose outside the door. The result can be compared to the desired criterion level (-0.04 + 0.02 inches water gauge). Another way to ensure range negative pressure is to use the smoke tube at all entrances or openings into the range (doors may need to be "cracked" a little to demonstrate. Smoke should enter into the range from outside areas.

Excessive negative pressure will make doors difficult to open (or to keep closed) and can be a safety hazard (slamming doors [- 0.05 - 0.10 inches water gauge]). Excessive negative pressure also indicates insufficient supply air for the amount being exhausted.

5.3 Air sampling. Air sampling in the personal breathing zone of shooters and range instructors is imperative in assessing exposures. Follow the procedures presented in the NEHC Industrial Hygiene Field Operations Manual (IHFOM) and the sampling and analysis requirements of the Industrial Hygiene Sampling Guide for Consolidated Industrial Hygiene Laboratories. In order to properly assess health risks and classify the range, the following information should be recorded in addition to the required data presented in the IHFOM: The type of training being conducted; frequency of training; number of shooters; shooter placement (lane number); weapon type(s); caliber and manufacturer of the ammunition; jacketed or non-jacketed bullets; number of rounds expended; other activity that would contribute to exposure.

Compare the air sampling results to permissible exposure limits or the administrative control table for the range being used (see Appendix A). Based on the exposure results and the facility or operational requirements, classify the range per OPNAVINST 5100.23 Series, Section 6 and Appendix A of this guide.

5.4 Range cleaning. Floors and horizontal surfaces should be cleaned on a regular basis.

Cleaning frequency depends on how heavily the range is used. Floor and horizontal surfaces such as booth shelves or target retrieval systems may need daily cleaning if heavily used.

Otherwise, cleaning should be performed once or twice a week. Cleaning can be conducted either with a vacuum equipped with a high efficiency particulate air (HEPA) filter or wet methods. Consideration for an explosion-proof HEPA vacuum is necessary due to the possibility of buildup of unburned powder. The vacuum should be dedicated for the lead dust cleanup.

Individuals performing cleaning operations should be properly trained and not try to hurry the process. Dry sweeping or the use of compressed air to "blow down" the range should be prohibited. The cleanup of spent shell casings ("brass") should not use brooms (a wooden "casino rake" can be useful). The ventilation system should be on during cleanup operations.

Appendix D provides guidance for indoor range cleaning.

5.5 Hygiene. Specific practices should be in place to prevent the ingestion of lead or the contamination of other areas by range personnel/shooters.

5.5.1 Personnel and shooters should know what areas of the range they are allowed access to and in what spaces clothing or skin may become contaminated. Shooters should not be allowed past the firing line. Disposable shoe coverings should be available for individuals who may have to walk down the range. Sticky walk-on mats should be available at the exit door to remove dust from shoes of individuals exiting the range.

5.5.2 The use or consumption of food, beverages, tobacco, gum or cosmetics should be prohibited in the range. Lead dust on hands can easily contaminate such items.

5.5.3 Shooters should wash hands and face thoroughly before consuming food, beverages, etc. For operations where contamination is likely, personnel should vacuum off their clothing with a HEPA vacuum before exiting the range. Vacuuming should reduce the spread of lead dust contamination to other areas of the building or to personal vehicles or quarters.

5.5.4 Washroom facilities should be provided with hot and cold water and soap or a powdered skin cleanser. A change room must be provided with showers (if feasible) if personnel are exposed above the permissible exposure limit. If a break (lunch) room is available, it should have smooth, easily cleanable surfaces. It must be cleaned often enough to maintain surface dust loading less than 200 μg/ft2 (OSHA CPL 2-2.58). An active range should not be used as a storage or office area.

5.5.5 Proper protective clothing must be maintained and available for personnel who perform range maintenance or cleaning where contamination is likely.

5.5.6 To limit contamination of objects, bags and clothing, only the weapon to be fired and the necessary ammunition should be carried into the range. Coat racks or lockers external to the range are recommended.

5.5.7 Range support and cleaning equipment should be easily accessible but in a separate storage closet.

5.6 Surface contamination assessments. To determine contamination levels of lead dust or to determine the effectiveness of cleanup, surface wipe sampling is performed. Follow the procedure in Appendix B or consult the laboratory for specific instructions. Once deposited, leaded dust is difficult to clean effectively. Cleaning is the process of removing visible debris and dust particles too small to be seen by the naked eye. Wipe samples for settled leaded dust can be collected from floors, interior contact areas, and other reasonably smooth surfaces.

6.0 Control measures.

6.1 Substitution with less hazardous materials is the most desirable means to control lead exposure. Reduced lead or "lead-free" ammunition has been developed. If allowed by the cognizant training activity, these "lead-free" alternatives should be considered for use. Lead exposures can be reduced by using jacketed rounds. Non-lead bullets are being developed that provide similar ballistic properties. Non-lead primers are also being developed using diazo-dinitro phenol (Dynol).

6.2 Ventilation systems used in ranges can be effective in controlling lead exposures.

Existing systems may be inadequate. Some systems may be retrofitted to improve their performance, however, ventilation system modifications require engineering analysis by professionals experienced in indoor firing range ventilation design. For engineering support, contact the Naval Facilities Engineering Command, Technical Center of Expertise, Mr. Bill Gibbings at (757) 322-4205. Because any modification of a system can affect the operation of other parts of the system, a thorough evaluation of the system as a whole is necessary. "Self-help" modifications rarely improve the control of exposures.

6.3 Maintenance. No system, regardless of design, can be effective over time without proper maintenance. The evaluation of the ventilation system and recommended modifications should take into consideration the availability of qualified personnel committed to proper maintenance.

6.4 Administrative. Administrative controls or range operational policies, although least desirable, can be used to reduce exposures. This can take the form of limiting exposure time (limiting range use). This should be part of the range's standard operating procedure and included into the range classification and operational recommendations per OPNAVINST

5100.23 Series and Appendix A. Other lead exposures resulting from hobbies, off-duty shooting and other work duties such as soldering can contribute to the individual's total lead exposure and should be considered in the maximum allowable exposure time.

7.0 Acceptance Testing

7.1 Background – Sections 3 and 5 presented general elements for conducting a basic industrial hygiene characterization with consideration for obtaining the necessary information (including monitoring) to assess health risks following the requirements of Chapter 8 of OPNAVINST 5100.23 Series. These evaluations assess hazards based on the operation, tasks and work practices taking place in the operating range. Major changes in a range due to changes in operation, general life cycle maintenance or by major modifications as recommended by the NAVFAC Technical Center of Expertise, would require an industrial hygiene reevaluation. After major contracted modifications, it may be desirable to conduct an initial evaluation to demonstrate the effectiveness of the facility at the maximum operational (designed) capability to document the completion of the work and to have a baseline industrial hygiene assessment for the range’s operational SOP.

7.2 A generic industrial hygiene acceptance test for small arms indoor ranges is provided in Appendix F.

Appendices

Appendix A

Health Considerations for Routine Range Use/Cleanup:

Generic Standard Operating Procedure for Training Type Indoor Small Arms Ranges

Section 1 General

Note: Contents of this standard operating procedure (SOP) include only the considerations to reduce personal exposure during routine range use and cleanup, and to reduce the chances of spreading contamination or taking toxic contaminants home at the end of the work day. This SOP does not include other requirements that are necessary per OPNAVINST 5100.23 Series and OPNAVINST 3591.1C as determined by local evaluations. Applicable portions of this SOP may be used in a range's overall operating SOP. [The determination for use and content of the bracketed items are based on local industrial hygiene evaluations].

Note: The Commanding Officer (Safety Office) of the activity owning the indoor range facility has oversight responsibility to ensure safe operation. These use and cleaning requirements will help ensure the safety and health of Navy personnel.

1.1 References:

Navy Instructions OPNAVINST 5100.23 Series, "Navy Occupational Safety and Health Program Manual" OPNAVINST 3591.1C, "Small Arms Training and Qualification"

Navy Technical Manuals Industrial Hygiene Field Operations Manual (IHFOM) - NEHC, Latest Revision

Military Handbooks MIL-HDBK-1027/3B, "Range Facilities and Miscellaneous Training Facilities Other than Buildings" To be replaced by Draft UFC 4-160-01, 15 March 2002 “Design and Maintenance of Small Arms Ranges.”

Code of Federal Regulations 29 CFR 1910.1025, Lead (General Industry) 29 CFR 1926.62, Lead (Construction)

1.2 Definitions

1.2.1 Action Level - Employee exposure, without regard to use of respirators, to an

A-1 airborne concentration of lead of 30 micrograms per cubic meter of air, time weighted averaged over an 8- hour period (30 μg/m3 8-hr TWA).

1.2.2 Area Sampling - Sampling of lead concentrations within the lead control area and inside the physical boundaries. It is representative of the airborne lead concentrations but is not collected in the breathing zone of personnel.

1.2.3 High Efficiency Particulate Air (HEPA) Filter Equipment - Vacuuming equipment with a HEPA filter system capable of collecting and retaining lead-contaminated particulate. A high efficiency particulate (HEPA) filter has been certified as at least 99.97 percent efficient for 0.3 micron or larger size particles.

1.2.4 Industrial Hygiene Range Classifications:

1.2.4.1 "Unlimited" classification - Based on industrial hygiene and use evaluations, an indoor range classification of "Unlimited" permits authorized firing for military and civilians.

1.2.4.2 "Limited" classification - A "Limited" classification permits use under specified controlled conditions.

1.2.4.3 "Restricted" classification - A "Restricted" classification indicates the range is not authorized for use under any conditions. It will not be used for any other purpose (i.e., storage, office space, classrooms or dining facilities) without first being decontaminated.

1.2.5 Permissible Exposure Limit (PEL) - Fifty (50) micrograms per cubic meter of air as an 8- hour time weighted average (50 μg/m3 8-hr TWA) as specified in OPNAVINST 5100.23 Series and 29 CFR 1910.1025.

1.2.6 Personal Sampling - Sampling of airborne lead concentrations within the breathing zone of an employee to determine the 8-hour time weighted average concentration in accordance with the IHFOM (NEHC) and OPNAVINST 5100.23 Series. Samples shall be representative of the employees' work tasks. Breathing zone shall be considered an area within a hemisphere, forward of the shoulders, with a radius of six to nine inches and centered at the nose or mouth of an employee.

1.3 Basis for exposure/cleaning determinations:

1.3.1 Maximum effort will be made to reduce the airborne lead levels below the action level of 30 micrograms per cubic meter (30 μg/m3) per OPNAVINST 5100.23 Series.

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1.3.2 Lead exposures for personnel are determined by a sampling strategy that employs breathing zone samples. Once an airborne lead concentration is determined, the maximum allowable hours of exposure for each category of range user can be established (see Attachment

(1) of Appendix A). Other potential lead exposures, including other training/duty firing, may contribute to an individual's overall exposure and should be considered in establishing maximum allowable exposure time or personal protective equipment recommendations.

1.3.3 The following factors are critical to proper range evaluation:

1.3.3.1 - Sample during periods of maximum use.

1.3.3.2 - Sample during the use of higher-caliber ammunition if more than one type of ammunition is used.

1.3.3.3 - Follow the sampling procedures in the IHFOM (NEHC).

1.4 Operational considerations to reduce exposures:

1.4.1 Range Classification - Indoor ranges should be classified as "unlimited," "limited," or "restricted" based on industrial hygiene evaluations. An industrial hygienist may classify indoor ranges as limited with permits for use under controlled conditions. Exposure limits for intermittent atmospheric lead exposure must be used for limited operation of the indoor range (see MIL-HDBK-1027/3B (To be replaced by UFC 4-160-01) and Attachment (1)).

1.4.1.1 Based on local industrial hygiene (IH) evaluations required by OPNAVINST 5100.23 Series, the range is classified [unlimited] [limited] for the listed weapon(s) based on the following scenario, including the number of shooters and expended rounds. Example Range Classification:

[Limited Range Classification - 38 cal or 9 mm - 8 shooters - Hand Gun Qualification Course - Total 50 rounds/person]

1.4.2 Shooters shall never move forward of the firing (red) line during firing.

1.4.3 Shooter’s hygiene

1.4.3.1 Eating, drinking or smoking are prohibited in an active firing range.

1.4.3.2 All shooters shall wash hands after turning in weapons. [If no washing facilities are available, shooters must use wet wipes to clean hands prior to exiting range.]

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Section 2 Products

2.1 Chemicals

2.1.1 Ensure applicable Material Safety Data Sheets are available for all chemicals used in range cleanup work.

Section 3 Execution

Note: Cleaning indoor ranges routinely as outlined or specified below should be the norm and is presumed to be sufficient to protect human health and the environment.

3.1 Equipment and Engineering Controls:

3.1.1 HEPA filter vacuuming is the only vacuum method authorized for range cleaning.

All generated waste must be disposed of as hazardous material. If a HEPA vacuum cleaner cannot be obtained, wet mopping may be used. Dry sweeping is prohibited. Use of compressed air is prohibited.

3.1.2 The range ventilation system must remain on at all times during cleaning. The ventilation system must be evaluated per the requirements of Chapter 21 of OPNAVINST

5100.23 Series. Filter replacement shall be based on the following schedule or when static pressures exceed recommended levels [insert recommended level in inches water gauge ( "wg)].

~ Pre-filters [for example, monthly] ~Secondary filters [for example, quarterly] ~HEPA filters [for example, annually]

3.2 Protection - Annual Cleaning

3.2.1 Operational ranges must have a complete and comprehensive cleaning annually.

Special training, equipment and [medical surveillance] are required for personnel assigned range cleaning responsibilities.

Note: Depending on bullet stop and other use or configuration factors, comprehensive cleaning may be required at frequencies other than annual.

3.2.2 All rooms and surfaces should be cleaned using the HEPA vacuum cleaning process or wet mopping methods, except for those that were found not to have lead hazards and were properly separated from shooting areas. If exterior cleanup work was conducted or if

A-4 debris was stored or dropped outside during cleaning, sidewalks, driveways, and other exterior surfaces should be vacuumed. Vacuuming should begin on the ceilings, end on the floors and be sequenced to avoid passing through areas already cleaned.

3.2.3 Respiratory protection and personal protective equipment requirements will be determined during the industrial hygiene assessment of the range. Respirator use will depend on exposure levels. If exposures are above the permissible exposure limit, the minimum respiratory protection is a half-mask HEPA cartridge (N, R or P-100) respirator. See OPNAVINST 5100.23 Series for respirator program requirements.

3.2.4 Full body protection is [not] required during range cleaning. [Disposable or cloth coveralls are authorized for use with booties or shoes dedicated for the job. After use, non-disposable coveralls must be sealed in bags with the appropriate labeling required by OPNAVINST 5100.23 Series and 29 CFR 1910.1025. Contracted laundry services must be informed of the lead contamination.]

3.2.5 [All openings of the protective clothing should be closed by taping.]

3.2.6 [Gloves are required to preclude skin contact. Glove type selection is dependent on level of mechanical protection (hand cleaning of metal surfaces that may have burrs would require leather).]

3.2.7 Annual medical surveillance is required for all employees who are or may be exposed to lead in excess of the action level for more than 30 days a year or as required by OPNAVINST 5100.23 Series.

3.2.8 Train each employee performing lead cleaning work or disposal operations prior to the time of initial job assignment and annually thereafter, in accordance with OPNAVINST

5100.23 Series, and State and local regulations where appropriate.

3.3 Protection - Routine Cleaning

3.3.1 Routine range cleaning shall be conducted after every [insert #] training evolution(s). [Daily cleaning using wet wipes shall be conducted on all horizontal surfaces in each used shooting station.]

3.3.2 Clean using HEPA vacuums or wet mopping methods sequenced to avoid passing through areas already cleaned. For example, start at the firing line area and end at the bullet stop. [Routine cleaning may end just at the firing line if access past the line is prohibited and strictly enforced by instructors]. [Cleaning is restricted to floor or horizontal surfaces only].

Note that brass cleanup may require access past the firing line.

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3.3.3 Respiratory protection and personal protective equipment requirements will be determined during the industrial hygiene assessment of the range. Respirator use will depend on exposure levels. If exposures are above the permissible exposure limit, the minimum respiratory protection is a half-mask HEPA cartridge (N, R or P-100) respirator. See OPNAVINST 5100.23 Series for respirator program requirements.

3.3.4 Full body protection is [not] required during range cleaning. [Disposable or cloth coveralls are authorized for use with booties or shoes dedicated for the job. After use, non-disposable coveralls must be sealed in bags with the appropriate labeling required by OPNAVINST 5100.23 Series and 29 CFR 1910.1025. Contracted laundry services must be informed of the lead contamination.]

3.3.5 [All openings of the protective clothing should be closed by taping.]

3.3.6 [Gloves are required to preclude skin contact. Glove type selection is dependent on level of mechanical…