HETA 91-287-2228 NIOSH INVESTIGATORS:

JUNE 1992 Carol H. Rubin, DVM, MPH

OHIO DEPARTMENT OF AGRICULTURE Alan Echt, MPH, CIH

REYNOLDSBURG LABORATORY Randy L. Tubbs, PhD

REYNOLDSBURG, OHIO

I. SUMMARY

On October 11, 1991, November 25-26, 1991, and February 7, 1992, investigators from

the National Institute for Occupational Safety and Health (NIOSH) conducted a Health

Hazard Evaluation (HHE) at the Ohio Department of Agriculture (ODA) laboratory in

Reynoldsburg, Ohio. This HHE was performed in response to a confidential employee

request concerning microbiological safety in the laboratory. In addition, once the HHE

was in progress, ODA management requested an evaluation of noise exposures in the

necropsy suite, in the electron microscopy lab, and in a veterinarian's office. 

NIOSH investigators administered a questionnaire to employees in Buildings 3, 4, and 6

at the Reynoldsburg labs, performed industrial hygiene measurements during the

operation of the Kjeldahl apparatus, evaluated selected laboratory hoods with a

thermoanemometer and smoke tubes, and measured noise in the specified areas. The

results of air sampling for sulfates, including sulfuric acid, did not reveal concentrations

above the limit of detection of the method (2.0 μg/sample). The results of air

sampling for sulfur dioxide are not presented in this report due to flaws in the analytical

method. The recommendations contained in this report address the control of potential

exposures through improved laboratory ventilation. Therefore, no further sampling was

performed. Face velocity at the hood (a class II, type B biological safety cabinet) in

room 134 in Building 6 was measured at 130 feet per minute (fpm) with the sash open

to its usual working position. Smoke tube tests at this hood demonstrated good capture

and no spillage of smoke outside of the hood. The average face velocity of the hood (a

class I biological safety cabinet) in room 133 in building six was 28 fpm, measured at

the opening in the plexiglass cover in front of the hood. While smoke tubes showed

capture and no spillage, this face velocity should be compared with design values to

determine if it is adequate. Noise measurements were conducted to sample the kinds of

noise exposures that the department's veterinarians may encounter during post mortem

examinations of animals delivered to the laboratory. Also, NIOSH investigators

evaluated exposures to total and respirable particulates generated by electric saws used

in necropsy.

The major sources of noise noted in the necropsy laboratory were a Wellsaw and

Stryker saw that are used to remove the spinal column, bisect skulls, or open the

cranium of animals. Because of the number of animals available to the veterinarians

during the visit, the personal noise sampling was limited to the 90 minutes that it took

for the veterinarians to complete their work. Both veterinarians wore ear muffs while

sawing. Noise levels ranged from 93 to 98 dB(A), but the sawing activities were of

short duration, ranging from 12 seconds to 1 minute 37 seconds. Noise from the

ventilation system in the necropsy lab, noise in the veterinarian's office, and noise in the

electron microscopy lab exceeded recommended Noise Criteria Curves for laboratory

facilities where communication is necessary. These criteria have been devised to limit

noise to levels where satisfactory speech intelligibility is obtained. The Noise Criteria

Curves were derived from data obtained during extensive interviews with personnel in

offices, factories, and public places along with simultaneously measured octave-band

sound levels. The noise levels in these areas did not approach those associated with the

development of noise-induced hearing loss.

This Health Hazard Evaluation (HHE) report and any recommendations made herein are for the specific facility evaluated and may not be universally

applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved.

Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports

This Health Hazard Evaluation (HHE) report and any recommendations made herein are for the specific facility evaluated and may not be universally

applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved.

Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports

This Health Hazard Evaluation (HHE) report and any recommendations made herein are for the specific facility evaluated and may not be universally

applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved.

applicable. Any recommendations made are not to be considered as final statements of NIOSH policy or of any agency or individual involved.

Additional HHE reports are available at http://www.cdc.gov/niosh/hhe/reports
Analyses of samples for total particulates collected during necropsy did not reveal

concentrations above the limit of detection of the method (LOD: 0.01 mg). The results

of air sampling for respirable particulates produced during necropsy were inconclusive. 

NIOSH investigators did not return to perform additional sampling do to the fact that

the results of sampling for total particulates indicated that sampling for respirable

particulates would reveal even lower concentrations.

The results of interviews and questionnaires revealed that 91% of the employees in

Buildings 3, 4, and 6 participated in the survey. In addition, four maintenance

employees requested to be included in the sample. Although the majority of laboratory

employees reported ready access to gloves and disposable respirators, there was a great

deal of variability in the use of this personal protective equipment. Similarly, there

were inconsistencies in the storage locations for food and personal items, the wearing of

lab coats or uniforms while eating, and the home laundering of work-specific clothing. 

Although 35% of the lab workers were aware of the classification of disease organisms

according to biosafety level, only one employee reported having received any such

training while working at the Reynoldsburg labs, and none of the employees could

correctly identify the biosafety level of the organism or disease that they worked with

the majority of the time. 

On the basis of the data obtained during this investigation, the

NIOSH investigators determined that a potential hazard exists for the

transmission of infectious organisms to laboratory workers in

Building 6, due to the lack of a comprehensive biological safety

program at the ODA Reynoldsburg labs. In addition, Building 3

requires extensive renovations to return laboratory ventilation

systems to recommended operating parameters. Recommendations to

address these problems are presented in Section IX of this report.

Keywords: SIC 8734 (Testing Laboratories), biosafety, agricultural, microbiological

and biomedical laboratories, noise.
Page 3 - Health Hazard Evaluation Report No. 91-287

II. INTRODUCTION

On October 11, 1991, November 25-26, 1991, and February 7, 1992, NIOSH

investigators conducted a Health Hazard Evaluation (HHE) at the Ohio Department of

Agriculture (ODA) laboratory facility in Reynoldsburg, Ohio. This HHE was

performed in response to a confidential employee request concerning microbiological

safety in the laboratory. In addition, at the request of the Building 6 laboratory director,

noise exposures were evaluated in the necropsy suite, in the electron microscopy

laboratory, and in a veterinarian's office. A letter dated October 29, 1991, reported the

results of the October 11 visit. This report presents results and recommendations from

all three site visits.

The October 11 investigation consisted of an initial meeting with three representatives

from management, two from Ohio Civil Service Employees Association (OCSEA)

Local 4550, and two employees, followed by a lengthy walk-through inspection of

Buildings 3, 4, and 6. During the walk-through, informal interviews were conducted

with several employees, and this information was used to construct the questionnaires

that were administered during subsequent visits. An interim letter, dated October 29,

1991, outlined preliminary recommendations for improving the quality of biosafety

practices at the Reynoldsburg labs. Suggestions included the implementation of a

comprehensive and standardized safety program (as outlined in HHS Publication No.

88-8395, Biosafety in Microbiological and Biomedical Laboratories), immediate repair

of damaged asbestos ductwork, and the rapid implementation of planned renovations

which would include the replacement of nonfunctional fume hoods in Building 3.1

 

III. BACKGROUND

Six Divisions are located at the ODA's Reynoldsburg Laboratory Complex. Included in

the HHE request were the Animal Industry Division (Building 6) and the Division of

Consumer Analytical Laboratories (Buildings 3 and 4). Building 6 receives, records,

and routes all mailed and delivered specimens both internally and to other buildings and

Divisions. A wide variety of procedures, ranging from gross pathology to avian

serology, are performed within Building 6. Employees in this building conduct a

variety of diagnostic tests, involving potential exposure to animal tissues, blood, serum,

and feces. Diagnostic tests include identification of Brucella, Salmonella, Shigella, Leptospira, and Mycobacterium species, as well as rabies and other viruses that are

potentially transmissible to humans in an occupational setting.2,3 In many cases an

individual employee's time is divided between different rooms and different disease

organisms. In Building 3, scheduled for major renovation and only partially occupied at

the time of the site visits, feed and fertilizer analyses are conducted. In Building 4

general chemical and microbiological analyses on a variety of samples, including milk,

meat, feeds, and fertilizers, are performed. Pesticide formulation and residue analyses

are also done in this building. 

IV. MEDICAL EVALUATION

Methods

Questionnaires addressing workplace exposure, work practices, and general health

(including presence of chronic diseases such as diabetes, and occurrence of
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gastrointestinal events such as diarrhea and constipation) were administered on a

voluntary basis to all employees in Buildings 3, 4, and 6, as well as to maintenance

staff. These questionnaires were administered by NIOSH investigators on November 25

and 26, 1991. Employees unavailable on those dates were contacted on February 7,

1992. Fifty-one (91%) of the 56 laboratory workers, and 4 self-selected maintenance

workers participated. Respondents were 62% female, ranged in age from 24 to 62 years 

 (mean=42 years), and had worked at the Reynoldsburg labs for a mean of 11 years

(range= 2 to 26 years). 

V. INDUSTRIAL HYGIENE EVALUATION

Materials and Methods

On November 25, 1991, four personal breathing zone (PBZ) and two general area (GA)

air samples were collected for total sulfates and sulfites, sulfur dioxide and sulfur

trioxide at the Kjeldahl apparatus. Two PBZ and one GA sample were collected in the

morning. In the afternoon, two additional PBZ samples and one additional GA sample

were collected. Personal samples were collected in the breathing zones of the flame

photometrist and the Kjeldahl operator, while the area sample was located just outside

the sash of the hood enclosing the apparatus. Samples were collected and analyzed

according to NIOSH Method 6004.4 Samples were collected using two filters in series

connected via Tygon tubing to a personal sampling pump operating at a flow rate of 

 1.0 liter per minute (lpm). The first filter, a 37 millimeter (mm) diameter, 0.8

micrometer (μm) pore size, mixed cellulose ester filter is used to collect sulfuric acid,

sulfate salts and sulfite salts, which are quantitated as total particulate sulfate and

sulfite. A second filter, identical to the first, except that it is treated prior to sample

collection with a solution of potassium hydroxide and glycerol, collects gaseous

sulfates. All samples were analyzed by ion chromatography.

On February 7, 1992, two PBZ samples for total particulates and two PBZ samples for

respirable particulates were collected in the necropsy suite while two veterinarians

performed dissections. One sample of each type was collected in the breathing zone of

each veterinarian. Air samples for total particulates were collected using tared 37 mm

diameter, 5 μm pore size polyvinyl chloride (PVC) filters connected via Tygon tubing to

personal sampling pumps operating at 2.0 lpm. Filters were weighed according to

NIOSH Method 0500, with modifications: 1) The filters are stored in an

environmentally controlled room (21+3 °C and 40+3% relative humidity) and are

subjected to these conditions for a long time for stabilization.4 This reduces the

stabilization time between tare weighings from 8-16 hours to 5-10 minutes. 2) The

filters and backup pads are not vacuum desiccated. Respirable particulates were

collected using four-stage Marple cascade impactors connected via Tygon tubing to

personal sampling pumps operating at a flow rate of 2.0 lpm. Cascade impactors

contain a number of stages in series with graduated nozzle velocities and impaction

distances to effect a progressive separation of smaller and smaller particles as the

aerosol travels through the unit. Impactors operate on the principle that when a moving

stream is deflected from a straight course, the inertia of some of the particles in the

stream will prevent them from following the airstream, and thus diverted, they will

strike the deflecting obstacle. Particles were collected on tared PVC filters, which were

then re-weighed in accordance with NIOSH Method 0500.4 
Page 5 - Health Hazard Evaluation Report No. 91-287

Noise measurements collected in the necropsy suite, electron microscopy lab and a

veterinarian's office on November 25, 1991, were made with a Gen Rad model 1982

sound level meter with an octave band filter. The instrument was pre- and postcalibrated according to the manufacturer's instructions. Octave band measurements at

consecutive center frequencies of 31.5 Hertz (Hz) to 16 kilohertz (Khz) along with 

A-weighted and C-weighted sound level measurements were made while the ventilation

systems were operating in the necropsy suite and veterinarian's office, and while the

vacuum pump was running in the electron microscopy lab.

The noise dosimeters used in the February 7, 1992, survey were Metrosonics

Model dB301/26 Metrologgers, a small noise level recording device which is worn on

the waist of the employee with a 1/4 inch microphone attached to the worker's shirt

collar, or the shoulder area if the shirt has no collar. This dosimeter is designed to

measure noise in decibels, A-weighted levels (dB[A]) four times per second. The noise

measurements are integrated according to the Occupational Safety and Health

Administration (OSHA) noise regulation (see Evaluation Criteria section of this report)

for an entire minute and stored separately in the Metrologger for later analysis and final

storage. Each dosimeter was calibrated according to the manufacturer's instructions

before being placed on the worker. After the recording period was completed, the

dosimeter was removed from the worker and placed in the standby mode of operation. 

The data were later transferred to a Metrosonics Model dt-390 Metroreader/Data

Collector following the noise sampling. Prior to turning off the dosimeter, it was again

calibrated to assure that the device had not changed during the sampling period. The

dosimeter information was finally transferred to a personal computer with supporting

Metrosonics Metrosoft computer software for permanent data storage and later analysis.

Additional area noise samples were made on February 7, 1992, with a Larson-Davis

Laboratories Model 800B Precision Integrating Sound Level Meter. Octave band

measurements at consecutive center frequencies of 31.5 Hertz (Hz) to 16 kilohertz

(Khz) along with A-weighted and C-weighted scales were made in the center of

the laboratory while the ventilation system was operating. Also, A-weighted

measurements were made with the meter in the integration mode for each of the post

mortem operations that resulted in noise exposures to the veterinarians. Octave

measurements were made with the sound level meter integrating the sound energy over

a 1-minute period with a 3 dB exchange rate.

VI. EVALUATION CRITERIA

As a guide to the evaluation of the hazards posed by workplace exposures, NIOSH field

staff employ environmental evaluation criteria for the assessment of a number of

chemical and physical agents. These criteria are intended to suggest levels of exposure

to which most workers may be exposed up to ten hours a day, forty hours a week for a

working lifetime without experiencing adverse health effects. However, it is important

to note that not all workers will be protected from adverse health effects if their

exposures are maintained below these levels. A small percentage may experience

adverse health effects because of individual susceptibility, a pre-existing medical

condition, and/or a hypersensitivity (allergy). In addition, some hazardous substances

may act in combination with other workplace exposures, the general environment, or

with medications or personal habits of the worker to produce health effects even if the

occupational exposures are controlled to the limit set by the evaluation criterion. These
Page 6 - Health Hazard Evaluation Report No. 91-287

combined effects are often not considered by the evaluation criteria. Also, some

substances are absorbed by direct contact with the skin and mucous membranes, and

thus potentially increase the overall exposure. Finally, evaluation criteria may change

over the years as new information on the toxic effects of an agent become available.

The primary sources of environmental evaluation criteria for the workplace are the

following: 1) NIOSH Criteria Documents and Recommended Exposure Limits (RELs),

2) the U.S. Department of Labor, OSHA Permissible Exposure Limits (PELs), and 3)

the American Conference of Governmental Industrial Hygienists' (ACGIH) Threshold

Limit Values (TLVs).5,6,7 The OSHA PELs may be required to take into account the

feasibility of controlling exposures in various industries where the agents are used; in

contrast, the NIOSH-recommended exposure limits are primarily based upon the

prevention of occupational disease. In evaluating the exposure levels and the

recommendations for reducing those levels found in this report, it should be noted that

employers are legally required to meet those levels specified by an OSHA PEL.

A time-weighted average exposure level (TWA) refers to the average airborne

concentration of a substance during a normal eight- to ten-hour workday. Some

substances have recommended short-term exposure limits (STELs) or ceiling values

which are intended to supplement the TWA where there are recognized toxic effects

from brief high exposures.

A. Noise

Occupational deafness was first documented among metalworkers in the sixteenth

century.8 Since then, it has been shown that workers have experienced excessive

hearing loss in many occupations associated with noise. Noise-induced loss of

hearing is an irreversible, sensorineural condition that progresses with exposure. 

Although hearing ability declines with age (presbycusis) in all populations,

exposure to noise produces hearing loss greater than that resulting from the natural

aging process. This noise-induced loss is caused by damage to nerve cells of the

inner ear (cochlea) and, unlike some conductive hearing disorders, cannot be

treated medically.9

While loss of hearing may result from a single exposure to a very brief impulse

noise or explosion, such traumatic losses are rare. In most cases, noise-induced

hearing loss is insidious. Typically, it begins to develop at 4000 or 6000 Hz (the

hearing range is 20 Hz to 20000 Hz) and spreads to lower and higher frequencies. 

Often, material impairment has occurred before the condition is clearly recognized. 

Such impairment is usually severe enough to permanently affect a person's ability

to hear and understand speech under everyday conditions. Although the primary

frequencies of human speech range from 200 Hz to 2000 Hz, research has shown

that the consonant sounds, which enable people to distinguish words such as "fish"

from "fist," have still higher frequency components.10

The OSHA standard for occupational exposure to noise (29 CFR

1910.95) specifies a maximum PEL of 90 dB(A)-slow response for a duration of

8 hours per day.11 The regulation, in calculating the PEL, uses a 5 dB

time/intensity trading relationship. This means that in order for a person to be

exposed to noise levels of 95 dB(A), the amount of time allowed at this exposure
Page 7 - Health Hazard Evaluation Report No. 91-287

level must be cut in half in order to be within OSHA's PEL. Conversely, a person

exposed to 85 dB(A) is allowed twice as much time at this level (16 hours) and is

within his daily PEL. Both NIOSH, in its Criteria for a Recommended Standard,

and the ACGIH, in their TLVs, propose an exposure limit of 85 dB(A) for 8

hours, 5 dB less than the OSHA standard.12,13 Both of these latter two criteria also

use a 5 dB time/intensity trading relationship in calculating exposure limits.

Time-weighted average (TWA) noise limits as a function of exposure duration are

shown below:

Duration of Exposure Sound Level (dB(A))

 (hrs/day) NIOSH/ACGIH OSHA

16 80 85

8 85 90

4 90 95

2 95 100

1 100 105

1/2 105 110

1/4 110 115

1/8 115 *

 **

*No exposure to continuous or intermittent noise in excess of 115 dB(A).

**Exposure to impulsive or impact noise should not exceed 140 dB peak

sound pressure level.

The OSHA regulation has an additional action level (AL) of 85 dB(A) which

stipulates that an employer shall administer a continuing, effective hearing

conservation program when the TWA value exceeds the AL. The program must

include monitoring, employee notification, observation, an audiometric testing

program, hearing protectors, training programs, and recordkeeping requirements. 

All of these stipulations are included in 29 CFR 1910.95, paragraphs (c) through

(o). The OSHA noise standard also states that when workers are exposed to noise

levels in excess of the OSHA PEL of 90 dB(A), feasible engineering or

administrative controls shall be implemented to reduce the workers' exposure

levels. Also, a continuing, effective hearing conservation program shall be

implemented.

Noise produced at intensities less than is necessary to cause loss of hearing can be

disruptive in the workplace. Interference with speech and disruption of office

activities are possible results of unwanted noise. The results from the noise can be
Page 8 - Health Hazard Evaluation Report No. 91-287

deterrents to the efficiency and productivity of the office staff and can be

detrimental to the occupants' comfort and sense of well-being. Noise criteria for

enclosed spaces have been devised to limit noise to levels where satisfactory

speech intelligibility is obtained.14 These criteria were devised through the use of

extensive interviews with personnel in offices, factories, and public places along

with simultaneously measured octave-band sound levels. The interviews

consistently showed that people rated noise as troublesome when its speech

interference level is high enough to make voice communication difficult.

B. Sulfur Dioxide

Although the Kjeldahl apparatus produces sulfur trioxide (SO3), any SO3 that

escapes from the process will be oxidized rapidly to sulfur dioxide. Sulfur dioxide

(SO2) is a colorless, water-soluble gas which is severely irritating to the eyes,

mucous membranes, and skin. On contact with moist membranes, it rapidly forms

sulfurous acid (H2SO3). Acute exposures to SO2 above 10 parts per million (ppm)

are irritating to the eyes, nose, and throat, and can cause choking, coughing, and

increased mucous secretion. Repeated exposures to 10 ppm have caused

nosebleeds among exposed workers.15 Acute inhalation of large amounts of sulfur

dioxide can result in death from asphyxia.16 Bronchial asthma can also result

following acute exposure to SO2.

17

Individuals have varying sensitivity to the broncho-constricting effects of SO2. 

Experimental studies on healthy human volunteers at rest exposed to 1 ppm SO2

have shown that airway resistance is generally not affected after short-term

exposure, but decreases in forced expiratory airflow have been found in some

individuals after prolonged exposure.18 Deep breathing has been found to increase

airway resistance at exposures of 1 ppm.19 At exposures less than 1 ppm, persons

with mild asthma exhibited increased airway resistance during moderately heavy

exercise.20

In 1974, NIOSH recommended that occupational exposures to SO2 not exceed 2

ppm for up to a 10-hour TWA exposure over a 40-hour workweek.17 On the basis

of the results of four other epidemiological studies, available by 1977, NIOSH

reduced its recommended exposure limit from 2 ppm to 0.5 ppm for a 10-hour

TWA.21

The OSHA PEL for SO2, revised in 1989, is 2 ppm for an 8-hour TWA. OSHA has

also established a 15-minute STEL of 5 ppm.6 

C. Sulfuric Acid

Sulfuric acid is a severe irritant of the respiratory tract, eyes, and skin.22 In a recent

study of 248 lead-acid battery workers, no significant association was found

between exposures of up to 0.42 mg/m3 and symptoms of cough, phlegm,

dyspnea, and wheezing.23 However, the forced vital capacity (a measure of lung

function) in the group of workers with the highest exposure was lower than those

in the lower exposure group. Repeated exposure of workers has reportedly
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resulted in chronic conjunctivitis, tracheobronchitis, stomatitis, and dermatitis

(inflammation of the eyes, air passages, mouth, and skin, respectively).24

The NIOSH REL, OSHA PEL, and ACGIH TLV for sulfuric acid are

1 mg/m3.

5,6,7 Additionally, ACGIH has recommended a STEL of 3 mg/m3

.

7

D. Total and Respirable Particulates Produced at Necropsy

Three potential routes of exposure to infectious agents have been noted during

necropsy: Percutaneous exposure, e.g. injury by contaminated sharps, such as

needles, scalpels, or bone spicules; mucous membrane and open wound exposure,

e.g. contamination of conjunctivae, nose, mouth, abrasions, or lacerations by blood

or body fluids; or inhalation exposure to aerosols produced during evisceration,

washing of organs, squeezing and manipulation of tissues, and use of high speed

oscillating saws to cut bone and cartilage.25 The most frequent cause of laboratoryassociated infections is probably the inhalation of an infectious aerosol.26 Two

recent studies have investigated the role of surgical power tools in the production

of aerosols.25,27 One of these, a study of aerosols generated at human autopsy,

noted a peak concentration of respirable particles of 5700 particles/cc, when a

Stryker saw was used to remove the skull cap of a young male.25 All of the

particles captured in the saw operator's breathing zone were respirable (<10 μm),

with a mean diameter of 0.37 μm. The other study, where a Stryker saw was again

among the instruments evaluated, noted that blood was detected among the

aerosols generated, and that most of the particles collected were less than 5 μm.27

In addition, data collected at animal necropsy by the U.S. Army at Fort Detrick,

MD, noted that 30 test organisms were recovered from the air during the autopsy of

an animal dissected immediately after the intraperitoneal injection of 10 ml of a

culture of the test organism.28 While these studies indicate that the potential is

present for the production of infectious aerosols during necropsy, standards

specific to the evaluation of infectious aerosols do not exist. 

E. Laboratory Ventilation

A laboratory requires regulation of temperature, humidity, air pressure, air motion,

air cleanliness, light, sound, and vibration.29 Most aging laboratory facilities

(greater than fifteen years old) require extensive renovations to their heating,

ventilation, and air-conditioning (HVAC) systems.29 A recent survey found that

43% of the research facilities in the United States are more than 20 years old and

that they lack mechanical services to support current research needs.30 There are

several sources of information on the design and evaluation of laboratory

ventilation systems.1,29,31-34

The OSHA standard for Occupational Exposure to Chemical Hazards in

Laboratories defines a laboratory-type hood, and mandates that the chemical

hygiene plan include a requirement that fume hoods and other protective

equipment are functioning properly and that this plan specify measures that shall

be taken to ensure proper and adequate performance of such equipment.35 Section

C of Appendix A of this standard provides information on the design and

performance requirements of laboratory ventilation:
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1. The laboratory facility should have an appropriate general ventilation system

with air intakes and exhausts located so as to avoid intake of contaminated air;

the facility should have laboratory hoods and sinks.

2. The general laboratory ventilation system should provide a source of air for

breathing and for input to local exhaust ventilation devices; it should not be

relied on for protection from toxic substances released into the laboratory. It

should ensure that laboratory air is continuously replaced, preventing increase

of air concentrations of toxic substances during the working day, and should

direct airflow into the laboratory from non-laboratory areas and out to the

exterior of the building.

3. A laboratory hood with 2.5 linear feet of hood space per person

should be provided for every two workers if they spend most of their

time working with chemicals; each hood should have a continuous

monitoring device to allow convenient confirmation of adequate

hood performance before use. If this is not possible, work with

substances of unknown toxicity should be avoided or other types of

local ventilation should be provided.

4. Ventilated storage cabinets, canopy hoods, snorkels, etc., should be

provided as needed. Each canopy hood and snorkel should have a

separate exhaust duct.

5. Exhaust air from glove boxes and isolation rooms should be passed

through scrubbers or other treatment before release into the regular

exhaust system. Cold rooms and warm rooms should have provisions

for rapid escape and for escape in the event of an electrical failure.

6. Any alteration of the ventilation system should be made only if

thorough testing indicates that worker protection from airborne toxic

substances will continue to be adequate.

7. Four to twelve room air changes per hour is normally adequate

general ventilation if local exhaust systems such as hoods are used as

the primary method of control.

8. General air flow should not be turbulent and should be relatively

uniform throughout the laboratory, with no high velocity or static

areas; airflow into and within the hood should not be excessively

turbulent; hood face velocity should be adequate (typically 60-100

linear feet per minute).

9. Quality and quantity of ventilation should be evaluated on

installation, regularly monitored (at least every three months), and

reevaluated whenever a change in local ventilation devices is made.

The testing and evaluation of laboratory hoods is described in detail in ASHRAE

standard ANSI/ASHRAE 110-1985, Method of Testing Performance of Laboratory

Fume Hoods.36
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Finally, while the OSHA bloodborne pathogens standard applies only to exposures

to human blood, its components, and products made with human blood, the

standard requires the certification of biological safety cabinets when they are

installed, whenever they are moved, and at least annually.37

 

VII. RESULTS AND DISCUSSION

A. Medical

Results from the work practices portion of the survey are given in Table 1. Almost

all employees reported a variety of job tasks involving different room locations,

differing technical procedures, and different organisms. All laboratory employees

had ready access to disposable gloves, and 91% wore gloves at some point in the

work day. However, 49% of those that did wear gloves only used one pair daily. 

Ninety-five per cent of the lab workers felt that they had access to disposable

respirators and 54% reported using them on a daily basis. During the initial walkthrough inspection, only one worker was observed wearing a disposable respirator,

and none were seen using eye protection, although one-third of the surveyed

workers reported using eye protection.

During the initial walk-through inspection, several employees voiced concern

about a perceived excess of gastrointestinal disease among employees at the

Reynoldsburg lab complex. In response to these concerns, several questions

addressing incidence and prevalence of gastrointestinal symptoms were included in

the health status portion of the questionnaire. Eleven (31%) of the 36 workers in

Building 6 reported experiencing an episode of diarrhea (defined as 3 or more

loose stools in 24 hours) in the past twelve months, as compared to three (25%) of

the 12 workers in Building 4. No workers in Building 3 reported having had such

episodes in the previous twelve months. Only workers in Building 6 reported

experiencing 3 or more such episodes in the past year. Twenty-three (42%) of the 55 employees had, at some point, contacted a physician

for signs or symptoms related to the gastrointestinal tract. Seven (30%) had made

such medical contact within the past 24 months. Nine (16%) of the 55 employees

reported frequent abdominal cramping, one (2%) reported frequent vomiting, and

one (2%) reported unexplained weight loss in the past six months. B. Industrial Hygiene

1. Noise

The noise dosimeters were placed on the two veterinarians within a minute of

each other. Thus, the results from each can be directly compared to show the

influence of one's activities on the noise exposure of the other. The noise time

lines are shown in Figures 1 and 2. The high peaks seen in the two graphs

seem to coincide with each other fairly often. These peaks are the result of

the use of the saws in the post mortem operations. Of course, the peaks are

greater when the veterinarian is actually using the saw. The relatively low

noise exposures seen in Veterinarian #1's record from 15 minutes until 30

minutes is the result of this veterinarian leaving the laboratory. Overall, each
Page 12 - Health Hazard Evaluation Report No. 91-287

veterinarian had the same noise exposure of 81 dB(A) for the 90-minute

period. The peaks shown in the graphs had a maximum value of 99 dB(A) for

Veterinarian #1 and 98 dB(A) for Veterinarian #2.

Individual sawing activities were measured with a sound level meter. Each

measurement yields an equivalent level (Leq), a high and low root-meansquare level encountered during the measurement period, and the elapsed time

of the measurement. These values are shown in Table 2.

Each of the sawing activities was relatively short in duration, ranging from 12

seconds to 1 minute, 37 seconds. The majority of the post mortem work was

done with knives. The noise levels ranged from 93 dB(A) to 98 dB(A). The

loudest measurement recorded was for the midline split of the cow skull. This

was done with the skull on a metal table in the laboratory. The sawing caused

the skull to vibrate against the metal table, resulting in additional noise from

the skull rattling on the table.

The noise spectrum from the ventilation system is presented in Figure 3. The

measurements were made in the laboratory while no other noisy activities

were taking place. Included in the figure are the Noise Criteria (NC) Curves

for enclosed spaces that have been developed to evaluate noise conditions in

rooms that will allow satisfactory speech intelligibility.14 It can be seen in the

figure that the ventilation system noise slightly exceeds the NC-65 curve at

250, 500, 1000, and 2000 Hz octave bands, sounds which are included in the

Speech Interference Level (SIL) criteria used to evaluate the effects of noise

on speech intelligibility.37 Areas which falls into the NC criteria of NC-50 to

NC-60 have been designated as kitchens, laundries, shops, garages, machinery

spaces, power plants, or mechanical equipment control rooms where only

minimum levels of acceptable speech communication are required and there is

no risk of hearing damage. Areas with NC curves ranging from 55 to 70 are

classified as work spaces where speech or telephone communication is not

required, but where there must be no risk of hearing damage.38

The noise spectrum measured in the veterinarian's office and the electron

microscopy lab are presented in Figures 4 and 5. Noise measurements in the

veterinarian's office were made while the office was unoccupied. The

ventilation system was the only source of noise in the office while

measurements were made. As shown in Figure 4, noise in the veterinarian's

office exceeded the NC-60 curve at 125 Hz and exceeds the NC-55 curve at 

 250 Hz. Private offices, small conference rooms, libraries, classrooms, and

similar locations should be within the NC-30 to NC-35 noise criteria for good

listening conditions. Noise in this office could be controlled through the

installation of a noise-reducing diffuser in place of the air-supply diffuser

currently installed in the office. Figure 5 provides the results of noise

measurements conducted in the electron microscopy laboratory. The NC-55

curve is exceeded at 250 and 4000 Hz, the NC-60 curve is exceeded at 1000

and 2000 Hz, and the NC-65 curve is exceeded at 500 Hz. For moderately

fair listening conditions, laboratory work spaces are classified in the NC-40 to

NC-50 range. The miscroscope's vacuum pump was the primary noise source

in the lab. The A-weighted sound pressure level measured with this pump off
Page 13 - Health Hazard Evaluation Report No. 91-287

was 48 dB(A); with the pump on, the level increased to 66 dB(A). Enclosure

or relocation of the pump outside of the laboratory would reduce or eliminate

this noise. 

2. Particulates Produced at Necropsy

Analysis of samples for total particulate collected during necropsy did not

reveal concentrations above the limit of detection (LOD: 0.01 mg/filter) of

the method. Analysis of samples for respirable particulates was inconclusive. 

However, since the results for total particulates were less than the LOD, one

would not expect to find elevated concentrations of the respirable portion of

the particulates present. The Wellsaw, which was used for the majority of

work requiring a saw, appeared to direct the majority of the particles away

from the person using the saw.

3. Sulfuric Acid and Sulfur Dioxide

The results of ion chromatography analysis of the front filters did not reveal

concentrations of sulfate ions above the LOD of the method, estimated to be

2.0 μg/sample. Although sulfur trioxide is produced within the Kjeldahl

Apparatus, any SO3 that escapes from the apparatus would be oxidized rapidly

to sulfur dioxide. Therefore, the results of the analysis of the treated filters

were reported as SO2. However, the results of sulfur dioxide monitoring are

not reported here due to problems with the analytical method. The

recommendations contained in this report address controlling potential

exposures to sulfur dioxide through improved laboratory ventilation. 

Therefore, NIOSH investigators did not return to conduct additional sampling. 

4. Laboratory Ventilation

Laboratory ventilation in Building 3 was found to be inadequate. The exhaust

stack for the Kjeldahl apparatus terminates just beyond the fan on the roof,

and then turns downward. Employees in this lab report that odors are

noticeable in the laboratory under certain wind conditions. This may be due

in part to the design of the exhaust stack. NFPA 45 specifies that, "Exhaust

stacks should extend at least 7 feet above the roof." Most of the other hoods

in the building do not function at all. Employees reported, and there is

evidence (missing floor tiles, rusted laboratory cabinets) of roof leaks and

standing water. The supports for the manifold in the Kjeldahl apparatus itself

are rotted away, probably as a result of years of exposure to the process. The

manifold is currently supported on cinder blocks.

Laboratory fume hoods in Building 4 have not been certified since 1982. The

pesticide residue laboratory in Building 4 uses a large canopy hood as a

containment device. This is scheduled to be replaced. However, both the

micro lab and the pesticide laboratory are under positive pressure with regard

to the rest of the building. This is not recommended, as any vapors, gases, or

aerosols which evolved as the result of an accident would quickly spread

throughout the building. If these laboratories must be maintained under

positive pressure to protect their contents from contamination, airlocks which
Page 14 - Health Hazard Evaluation Report No. 91-287

exhaust to the building's exterior should be installed at the entrances to the

laboratories. Alternatives which would allow these labs to be placed under

negative pressure, such as filtration of air entering this laboratory, should be

explored. The performance of the other hoods in this building should be

evaluated. Due to the hazards associated with explosive perchlorates, the

perchloric acid hood's design and installation should be evaluated with regard

to the requirements in NFPA 45 for perchloric acid hoods.

Hoods in Building 6 are recertified annually. The two biological safety

cabinets that were evaluated demonstrated good capture of smoke. The only

eyewashes available in this building were eyewash bottles. The availability

and use of personal protective equipment and work practices should be

standardized based upon the requirements of a comprehensive biosafety

program. 

VIII. CONCLUSIONS

The variety of organisms potentially encountered by lab workers in Building 6 may

present a risk to their personal health. In many cases, these employees work with

unknown biological material that should be treated with utmost caution, following the

"universal precautions" specified for handling human blood and bodily fluids.1

Occupational risk of exposure to infectious organisms can be minimized by establishing

a comprehensive biological safety program, including organism-specific employee

training.

After reviewing the analytical procedures involving animal blood and tissue performed

in Building 3, it appears that the risk of infection is negligible because the procedures do

not involve techniques that result in the generation of aerosols or the risk of needle

sticks. Although the potential for exposure to infectious agents appears to be lower

compared to Building 6, all laboratory workers would benefit from active involvement

in a biosafety program.

The laboratory facilities in Building 3 are in extremely poor condition, and are clearly in

need of extensive renovations. Air sampling conducted at the Kjeldahl apparatus did

not document any overexposures to sulfuric acid, and was inconclusive regarding

exposure measurements of sulfur dioxide. Renovations to the exhaust ventilation

system should control any potential exposures to sulfur dioxide associated with the use

of the Kjeldahl apparatus. The facilities in Building 4 are in need of review to

determine whether they comply with recommended laboratory safety guidelines. Work

practices and facilities in Building 6 should be reviewed periodically with regard to

current recommended practices for biomedical laboratories. 

None of the noise levels measured in the necropsy suite during the short survey period

represent a risk to employees' hearing levels. The dosimetry documented levels of 81.2

dB(A) for the period. Even if the veterinarians were to continue these kinds of sawing

operations on animals for an 8-hour period, they would not exceed any of the evaluation

criteria for noise exposure. The dosimeters did, however, document noise levels up to

99 dB(A), which should be reduced. Additionally, the spectral measurements of the

ventilation system in the necropsy suite revealed that noise produced by the system

presents a situation where communication intelligibility will only be at minimal levels
Page 15 - Health Hazard Evaluation Report No. 91-287

of satisfaction. Noise in the veterinarian's office and in the electron microscopy

laboratory did not approach levels associated with risk of hearing loss. However,

spectral analysis of noise in these two locations indicate that the noise exceeded criteria

for satisfactory communication for these types of settings.

Air sampling for particulates produced during animal necropsy did not document

exposure to aerosols produced from saws used in these procedures. Recent studies have

shown that there is a potential for the generation of aerosols during the use of surgical

saws. Therefore, potential exposures to aerosolized biological material during necropsy

should be included in the biological safety program for Building 6; and personnel

involved in necropsy should utilize Safety Level Two precautions as described in

reference 1. 

IX. RECOMMENDATIONS

A. Medical

On the basis of information gathered during the walk-through, from the interviews,

and from the questionnaire data, NIOSH investigators offer the following

recommendations.

1. Implement a comprehensive safety program administered by a qualified

designated individual. This recommendation is based upon the questionnaire

finding that 98% of employees had not received standard biosafety training. 

In addition, since several employees, during the interview process, reported a

reluctancy to approach management with complaints regarding workplace

conditions, it is recommended that this safety program should also provide for

a means of communication that allows employees to voice their concerns

about workplace hazards and have those concerns addressed without a fear of

recrimination.

2. Institute standardized infection control precautions on a building-wide basis

for each of the three buildings. The walk-through inspection revealed the

variety of tasks performed, and organisms encountered, by an individual

worker. Building-wide standardization will avoid confusion resulting when

personnel switch back and forth among different levels of precaution. Based

upon a review of the potential agents encountered and the tasks performed,

these standardized precautions should include those outlined for Safety Level

Two in the Centers for Disease Control handbook on Biosafety in

Microbiological and Biomedical Laboratories (see appendix 1).

3. Provide adequate personal locker space that is separate from the labs so that

employees can keep personal items, such as food, purses, medications, and

street clothing separated from potential workplace exposures. At present

there is an obvious shortage of secure lockers and this may account for the

fact that over 80% of employees keep personal belongings in the laboratory

work area.

4. Ensure that lab coats or uniforms are readily available, especially for the 40%

of laboratory workers who do not routinely wear them at present. Discourage
Page 16 - Health Hazard Evaluation Report No. 91-287

the home laundering of work clothes or the wearing of street clothes while

working.

5. As relayed in previous correspondence and during our closing conversation,

there is a need for a responsible safety officer who will institute and supervise

on-the-job training for employees involved in handling biological samples. 

 B. Noise

Because of the noise results found during the survey, NIOSH investigators offer

the following recommendations to the Ohio Department of Agriculture.

1. The use of hearing protection devices (HPDs) during sawing operations

should be continued because of documented noise exposures of 99 dB(A)

resulting from the saws. Any type of HPD should be sufficient to attenuate

the noise levels found in the laboratory. Perhaps a semi-aural device which

can be worn around the neck when not in place would be more convenient to

the veterinarians. The semi-aural devices are commonly seen at airports on

employees who meet the aircraft at the gate areas. Any local safety supply

store should be able to furnish the Department of Agriculture with a list of

companies who produce this kind of HPD.

2. The rattling of the skull bone on the metal table can be eliminated by putting a

wooden butcher block in the necropsy lab for sawing this type of material. A

sealed butcher block can be easily disinfected so that infection control should

not be an issue with the use of a block.

3. A ventilation consultant should be hired to evaluate the ventilation system and

offer suggestions for noise reduction. While the noise emitted by the system

does not pose a hazard to the veterinarians' hearing ability, it does present

problems for communications between individuals in the laboratory. The

categorization of NC curves stipulates criteria between NC-40 to NC-50 for

laboratory work spaces where moderately fair listening conditions are

warranted.39

4. Noise in the veterinarian's office could be controlled through the installation

of a noise-reducing diffuser in place of the air-supply diffuser currently

installed in the office. 

5. Enclosure or relocation of the vacuum pump outside of the electron

microscopy laboratory would reduce the noise in that location.

C. Industrial Hygiene

Based upon the results of the walk-through, the following recommendations are

offered to ODA:

1. If the pesticide and microbiology laboratories in Building 4 must be

maintained under positive pressure to protect their contents from

contamination, airlocks which exhaust to the building's exterior should be
Page 17 - Health Hazard Evaluation Report No. 91-287

installed at the entrances to the laboratories. Alternatives which would allow

these labs to be placed under negative pressure, such as filtration of air

entering these laboratories, should be explored.

2. The performance of the other hoods in this building should be evaluated.

3. Due to the hazards associated with explosive perchlorates, the perchloric acid

hood's design and installation should be evaluated with regard to the

requirements in NFPA 45 for perchloric acid hoods.

4. Damaged ductwork in Buildings 3 and 4 suspected of containing asbestos

should be repaired immediately. Asbestos containing debris in the cellar

under Building 3 should be cleaned up. These procedures should be

performed by qualified individuals.

5. Building 3 is in need of extensive renovations in order to support current

ODA analytical laboratory responsibilities.

6. Personnel performing necropsies should be included in the biosafety program

and utilize suitable personal protective equipment.

7. The eyewash bottles in Building 6 should be replaced by eyewashes capable

of providing at least 15 minutes of continuous flow. Guidelines for the

selection, placement, and periodic inspection of eyewashes are found in ANSI

Z358.1-1981.

X. REFERENCES

1. Richardson JH, Barkley WE, ed. [1988]. Biosafety in microbiological and

biomedical laboratories. 2nd ed. Washington, D.C.: U.S. Department of Health

and Human Services, Public Health Service, Centers for Disease Control and

National Institutes of Health, DHHS (NIH) Publication No. 88-8395.

2. Committee on Hazardous Biological Substances in the Laboratory [1989].

Biosafety in the laboratory. Washington, D.C.: National Academy Press. 

3. Collins CH. Laboratory-acquired infections: history, incidence, causes and

prevention. 2nd ed. 1988. Butterworth & Co, London. 

4. NIOSH [1989]. Eller PM, ed. NIOSH manual of analytical methods. 3rd rev. ed. 

Cincinnati, OH: U.S. Department of Health and Human Services, Public Health

Service, Centers for Disease Control, National Institute for Occupational Safety

and Health. DHHS (NIOSH) publication No. 84-100.

5. CDC [1988]. NIOSH recommendations for occupational safety and health

standards 1988. Atlanta, GA: U.S. Department of Health and Human Services,

Public Health Service, Centers for Disease Control; National Institute for

Occupational Safety and Health. MMWR 37 (supp. S-7).
Page 18 - Health Hazard Evaluation Report No. 91-287

6. Code of Federal Regulations [1989]. 29 CFR 1910.1000. Washington, DC: U.S.

Government Printing Office, Federal Register.

7. ACGIH [1990]. Threshold limit values and biological exposure indices for 1990-

1991. Cincinnati, OH: American Conference of Governmental Industrial

Hygienists.

8. Alberti [1591 (1970)], cited by Bunch, C.C. Traumatic deafness. In E.P. Fowler,

Jr. (Editor), Medicine of the ear, chapter X. Reprinted Translations of the Beltone

Institute for Hearing Research, No. 23.

9. Ward WD [1986]. Anatomy & physiology of the ear: normal and damaged

hearing. Chapter 5. In: Berger EH, Ward WD, Morrill JC, Royster LH, eds. 

Noise & hearing conservation manual. 4th ed. Akron, OH: American Industrial

Hygiene Association, pp. 177-195.

10. Ward WD, Fleer RE, Glorig A [1961]. Characteristics of hearing loss produced

by gunfire and by steady noise. Journal of Auditory Research, 1:325-356.

11. Code of Federal Regulations [1989]. OSHA. 29 CFR 1910.95. Washington, DC: 

U.S. Government Printing Office, Federal Register.

12. NIOSH [1972]. Criteria for a recommended standard: occupational exposure to

noise. Cincinnati, OH: U.S. Department of Health, Education, and Welfare,

Health Services and Mental Health Administration, National Institute for

Occupational Safety and Health, DHEW (NIOSH) Publication No. 73-11001.

13. ACGIH [1990]. 1990-1991 threshold limit values for physical agents. 

Cincinnati, Ohio: American Conference of Governmental Industrial Hygienists.

14. Beranek LL [1957]. Revised criteria for noise control in buildings. Noise

Control, 3:19-27.

15. NIOSH [1981]. NIOSH/OSHA occupational health guidelines for chemical

hazards. Cincinnati, OH: U.S. Department of Health and Human Services,

Public Health Service, Centers for Disease Control, National Institute for

Occupational Safety and Health, DHHS (NIOSH) Publication No. 81-123.

16. NIOSH [1977]. Occupational diseases: a guide to their recognition (revised ed.). 

Cincinnati, OH: U.S. Department of Health, Education, and Welfare, Public

Health Service, Center for Disease Control, National Institute for Occupational

Safety and Health, DHEW (NIOSH) Publication No. 77-181.

17. NIOSH [1974]. Criteria for a recommended standard: occupational exposure to

SO2. Cincinnati, OH: U.S. Department of Health, Education, and Welfare,

Health Services and Mental Health Administration, National Institute for

Occupational Safety and Health, DHEW (NIOSH) Publication No. 74-111.
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18. Andersen I, Lundqvist GR, Jensen PL, Proctor, N [1974]. Human response to

controlled levels of sulfur dioxide. Arch Environ Health 28:31-39.

19. Lawther PJ, MacFarlane AJ, Waller RE, Brooks AGF [1975]. Pulmonary

function and sulfur dioxide: some preliminary findings. Environmental Research

10:355-367.

20. Bethel RA, Epstein J, Sheppard D, Nadel JA, Boushey [1983]. Sulfur dioxideinduced bronchoconstriction in freely breathing, exercising, asthmatic subjects. 

Amer Rev Resp Dis 128:987-990.

21. NIOSH [1977]. Congressional testimony: statement of Edward J. Baier, Deputy

Director, NIOSH, Center for Disease Control, Department of Health, Education,

and Welfare, Health Services and Mental Health Administration. Presented at the

public hearing on the occupational standard for SO2, May 1977. NIOSH Policy

Statements. Cincinnati, OH: U.S. Department of Health, Education, and Welfare,

Centers for Disease Control, National Institute for Occupational Safety and

Health.

22. Proctor N, Hughes J, Fischman M [1988]. Chemical hazards of the workplace. 

2nd ed. Philadelphia, PA: J.B. Lipincott Company.

23. Gamble J et al [1984]. Epidemiological - environmental study of lead acid

battery workers III. Chronic effects of sulfuric acid on the respiratory system and

teeth Environ Res 35:30-52.

24. NIOSH [1974]. Criteria for a recommended standard...occupational exposure to

sulfuric acid. Cincinnati, OH: U.S. Department of Health, Education and

Welfare, Public Health Service, Center for Disease Control, National Institute for

Occupational Safety and Health. DHEW(NIOSH) Publication No. 74-128.

25. Green FHY, Yoshida K [1990]. Characteristics of aerosols generated during

autopsy procedures and their potential role as carriers of infectious agents. Appl

Occup Environ Hyg 5:853-858.

26. Pike RM [1979]. Laboratory-associated infections: incidence, fatalities, causes,

and prevention. Ann. Rev. Microbiol. 33:41-66.

27. Heinsohn P, Jewett DL, Balzer L, Bennett CH, Seipel P, and Rosen A [1991].

Aerosols created by some surgical power tools: Particle size distribution and

qualitative hemoglobin content. Appl Occup Environ Hyg 6:773-776.

28. CDC. Infectious hazards of common microbiological techniques. Adapted from: 

Safety regulations, microbiological, chemical, and industrial safety, U.S. Army

Headquarters, Fort Detrick, MD. Atlanta, GA: Reprinted by the U.S. Department

of Health and Human Services, Public Health Service, Centers for Disease

Control.
Page 20 - Health Hazard Evaluation Report No. 91-287

29. ASHRAE [1991]. Laboratories. Chapter 14. In: 1991 ASHRAE Handbook: 

HVAC systems and applications. Inch-pound ed. Atlanta, GA: American

Society of Heating, Refrigerating, and Air-Conditioning Engineers.

30. Kiil, L [1984]. Aging labs need extensive renovation. In: 1991 ASHRAE

Handbook: HVAC systems and applications. Atlanta, GA: American Society of

Heating, Refrigerating and Air-Conditioning Engineers. pp. 14.1.

31. NRC Committee on Hazardous Substances in the Laboratory [1981]. Prudent

practices for handling hazardous chemicals in laboratories. Washington, D.C.: 

National Academy Press.

32. NFPA [1990]. Standard on fire protection for laboratories using chemicals. 

NFPA 45. Quincy, MA: National Fire Protection Association.

33. Di Beradinis L, Baum J, First M, Gatwood G, Groden E, Seth A [1987]. 

Guidelines for laboratory design: health and safety considerations. Boston, MA: 

John Wiley and Sons.

34. CRC [1989]. CRC handbook of laboratory safety. 3rd ed. Boca Raton, FL: 

CRC Press, Inc. 35. 55 Fed. Reg. 3300 [1990]. Occupational Safety and Health Administration: 

occupational exposures to hazardous chemicals in laboratories; final rule. (To be

codified at 29 CFR 1910.)

36. ASHRAE [1985]. Method of testing performance of laboratory fume hoods. 

Atlanta, GA: American Society of Heating, Refrigerating, and Air-Conditioning

Engineers. ANSI/ASHRAE Standard 110-1985.

37. 58 Fed. Reg. 64175 [1991]. Occupational Safety and Health Administration: 

occupational exposure to bloodborne pathogens; final rule (To be codified at 29

CFR 1910.)

38. ANSI [1977]. American national standard for rating noise with respect to speech

interference. New York, NY: American National Standards Institute, American

Institute of Physics for the Acoustical Society of America. ANSI Standard S3.14-

1977.

39. Beranek LL [1988]. Criteria for noise and vibration in communities, buildings,

and vehicles. Chapter 18. In: Beranek LL, ed. Noise and vibration control. 

Revised edition. Cambridge, MA: Institute of Noise Control Engineering, 

pp. 554-623.

XI. AUTHORSHIP AND ACKNOWLEDGEMENTS

Report Prepared by: Carol H. Rubin, DVM, MPH

Medical Officer
Page 21 - Health Hazard Evaluation Report No. 91-287

Medical Section

Surveillance Branch

Alan Echt, MPH, CIH

Industrial Hygienist

Industrial Hygiene Section

Hazard Evaluations and

 Technical Assistance Branch

Randy L. Tubbs, PhD

Psychoacoustician

Industrial Hygiene Section

Hazard Evaluations and 

 Technical Assistance Branch

Division Of Surveillance, Hazard 

 Evaluations and Field Studies

Field Assistance: John E. Kelly, MS

Industrial Hygienist

Industrial Hygiene Section

Hazard Evaluations and

 Technical Assistance Branch

Virginia Behrens, MS

Assistant Section Chief

Medical Section

Surveillance Branch

Catherine Connon, RN, MN

Occupational Health Nurse

Medical Section

Surveillance Branch

Division of Surveillance, Hazard 

 Evaluations and Field Studies

Analytical Support: Measurements Development Section

Measurements Research Support Branch

Division of Physical Sciences and 

Engineering

Data Chem Laboratories

Salt Lake City, Utah

Originating Office: Hazard Evaluations and

 Technical Assistance Branch

Division of Surveillance, Hazard

 Evaluations and Field Studies

XII. DISTRIBUTION AND AVAILABILITY OF REPORT
Page 22 - Health Hazard Evaluation Report No. 91-287

Copies of this report may be freely reproduced and are not copyrighted. Single copies

of this report will be available for a period of 90 days from the date of this report from

the NIOSH Publications Office, 4676 Columbia Parkway, Cincinnati, Ohio 45226. To

expedite your request, include a self-addressed mailing label along with your written

request. After this time, copies may be purchased from the National Technical

Information Service, 5285 Port Royal Rd., Springfield, VA 22161. Information

regarding the NTIS stock number may be obtained from the NIOSH Publications Office

at the Cincinnati address.

Copies of this report have been sent to:

1. Confidential Requester

2. Deputy Director, Ohio Department of Agriculture

3. Local 4550, Ohio Civil Service Employees Association

4. OSHA, Region V

5. NIOSH

For the purpose of informing affected employees, 42 CFR 85.11 requires the employer

to post copies of this report in a prominent place accessible to the employees for a

period of 30 calendar days.
Table 1

Results of questionnaire assessing work habits and 

safety knowledge of 55 laboratory employees. 

Ohio Department of Agriculture, Reynoldsburg, OH

November 25-26, 1991 and February 7, 1992

HETA 91-287

Work Practice/Knowledge % of employees

Change clothes when arrive at work 16

Usually wear a lab coat or uniform over street clothes* 60.5

Keep coat or jacket in the lab 42

Keep personal belongings such as purse in the lab 81

Keep lunch in the lab 9

Wear lab coat while eating lunch 33

Always wash hands before eating lunch 95

Wash hands in lab sink 83

Wear gloves at any point during the work day 91

Have ready access to disposable gloves 100

Have ready access to disposable masks 95

Wear masks at any point during the work day* 54

Ever wear eye protection* 33

Use at least some rebottled products 52

Think that majority of rebottled products aren't properly labeled 37

Disinfect their work surfaces <2 times/day rather than after every

procedure 

 41.5

EVER heard of Biosafety Classification of Disease 

Organisms*

 35 

Received ANY training on Biosafety levels while working at the

Reynoldsburg Labs* 2

* Calculation excludes strictly clerical workers.
TABLE 2

Sawing Activities in the Necropsy Laboratory

All noise levels are reported in dB(A)

Body Section

Saw

Time

(mm:ss) Leq High Low

Spinal Column

(pig) Wellsaw 00:12 88.7 93.3 73.0

Spinal Column

(pig) Wellsaw 00:16 93.1 96.0 77.5

Skull (pig) Stryker 01:37 89.0 93.8 85.0

Spinal Column

(cow) Wellsaw 01:15 94.3 97.5 76.8

Skull (cow):

midline split Wellsaw 00:33 98.1 100.4 80.8

Skull (cow):

midline split Wellsaw 00:14 93.4 96.0 69.3

Spinal Column

(cow) Wellsaw 00:59 96.8 100.8 76.8
Appendix 1

Biosafety in Microbiological and Biomedical Laboratories; 2nd edition May 1988. HHS

Publication No. (CDC) 88-8395. 

Standard Microbiological Practices

1) Access to the laboratory is limited or restricted by the laboratory director when work

with infectious agents is in progress.

 2) Work surfaces are decontaminated at least once a day and after any spill of viable

material.

3) All infectious liquid or solid wastes are decontaminated before disposal.

4) Mechanical pipetting devices are used; mouth pipetting is prohibited.

5) Eating, drinking, smoking, and applying cosmetics are not permitted in the work area. 

Food may be stored in cabinets or refrigerators designated for this purpose only. Food

storage cabinets or refrigerators should be located outside of the work area.

6) Persons wash their hands after handling infectious materials and animals and when they

leave the laboratory.

7) All procedures are performed carefully to avoid the creation of aerosols.

Special Practices

1) Contaminated materials that are to be decontaminated at a site away from the laboratory

are placed in a durable leak-proof container which is closed before being removed from

the laboratory.

2) The laboratory director limits access to the laboratory. In general, any persons who are

at increased risk of acquiring infection or for whom infection may be unusually

hazardous are not allowed in the laboratory or animal rooms. The director has the final

responsibility for assessing each circumstance and determining who may enter or work

in the laboratory.

3) The laboratory director establishes policies and procedures whereby only persons who

have been advised of the potential hazard and meet any entry requirements (e.g.,

immunization) enter the laboratory or animal rooms.

4) When the infectious agent(s) in use in the laboratory require special provisions for entry

(e.g., vaccination) a hazard warning sign, incorporating the universal biohazard symbol,

is posted on the access door to the laboratory work area. The hazard warning sign

identifies the infectious agent, lists the names and telephone number of the laboratory

director or other responsible person(s), and indicates the special requirement(s) for

entering the laboratory.

5) An insect or rodent control program is in effect.
6) Laboratory coats, gowns, smocks, or uniforms are worn while in the laboratory. Before

leaving the laboratory for nonlaboratory area (e.g., cafeteria, library, administrative

offices), this protective clothing is removed and left in the laboratory or covered with a

clean coat not worn in the laboratory.

7) Animals not involved in the work being performed are not allowed in the laboratory.

8) Special care is taken to avoid skin contamination with infectious materials; gloves

should be worn when handling infectious animals or when contact with infectious

materials is unavoidable.

9) All wastes from laboratories and animal rooms are appropriately decontaminated before

disposal.

 10) Spills and accidents which result in overt exposures to infectious materials are

immediately reported to the laboratory director. Medical evaluation, surveillance, and

treatment are provided as appropriate and written records are maintained. 

 11) When appropriate,considering the agent(s) handled, base-line serum samples for

laboratory and other at-risk personnel are collected and stored. Additional serum

specimens may be collected periodically, depending on the agents handled or the

function of the facility.

 12) A biosafety manual is prepared or adopted. Personnel are advised of special hazards

and are required to read instructions on practices and procedures and to follow them.