Evaluation of Occupational 

Exposures to Illicit Drugs at 

Controlled Substances 

Laboratories 

HHE Report No. 2018-0090-3366

January 2020
Authors: Kendra R. Broadwater, MPH, CIH

David A. Jackson, MD

Jessica F. Li, MSPH

Analytical Support: Bureau Veritas North America

Desktop Publisher: Aja Powers

Editor: Cheryl Hamilton

Industrial Hygiene Field Assistance: Karl Feldmann

Logistics: Donnie Booher, Kevin Moore

Medical Field and Analytic Assistance: Krishna Surasi, Marie de Perio

Keywords: North American Industry Classification System (NAICS) 922120 (Police Protection),

Maryland, Forensic Laboratory, Forensic Scientist, Forensic Chemist, Law Enforcement, Illicit

Drug, Cocaine, Fentanyl, Heroin, Opioid, Methamphetamine

Disclaimer

The Health Hazard Evaluation Program investigates possible health hazards in the workplace under

the authority of the Occupational Safety and Health Act of 1970 [29 USC 669a(6)]. The Health

Hazard Evaluation Program also provides, upon request, technical assistance to federal, state, and

local agencies to investigate occupational health hazards and to prevent occupational disease or

injury. Regulations guiding the Program can be found in Title 42, Code of Federal Regulations,

Part 85; Requests for Health Hazard Evaluations [42 CFR Part 85]. 

Availability of Report

Copies of this report have been sent to the employer, employees, and union at the laboratories. The 

state and local health departments and the Occupational Safety and Health Administration Regional

Office have also received a copy. This report is not copyrighted and may be freely reproduced.

Recommended Citation 

NIOSH [2020]. Evaluation of occupational exposures to illicit drugs at controlled substances 

laboratories. By Broadwater KR, Jackson DA, Li JF. Cincinnati, OH: U.S. Department of Health

and Human Services, Centers for Disease Control and Prevention, National Institute for

Occupational Safety and Health, Health Hazard Evaluation Report 2018-0090-3366, 

https://www.cdc.gov/niosh/hhe/reports/pdfs/2018-0090-3366.pdf. 
Table of Contents

Main Report

Introduction....................................................................................................................................................... 1

Our Approach ................................................................................................................................................... 1

Our Key Findings.............................................................................................................................................. 2

Our Recommendations.................................................................................................................................... 4

Supporting Technical Information 

Section A: Workplace Information............................................................................................................ A-1

Building...................................................................................................................................................... A-1

Employee Information ............................................................................................................................ A-1

Process Description ................................................................................................................................. A-1

Section B: Methods, Results, and Discussion .......................................................................................... B-1

Methods: Health and Safety Program and Document Review.......................................................... B-1

Results: Health and Safety Program and Document Review............................................................. B-1

Methods: Observations of Work Processes, Practices, and Conditions .......................................... B-3

Results: Observations of Work Processes, Practices, and Conditions ............................................. B-3

Methods: Exposure Assessment ............................................................................................................ B-6

Results: Exposure Assessment ............................................................................................................... B-8

Methods: Employee Health Assessment ............................................................................................ B-10

Results: Employee Health Assessment ............................................................................................... B-10

Discussion ............................................................................................................................................... B-13

Limitations............................................................................................................................................... B-19

Conclusions............................................................................................................................................. B-19

Section C: Tables.......................................................................................................................................... C-1

Section D: References.................................................................................................................................. D-1
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1

Introduction

Request

Management at a police forensic sciences division was concerned about potential unintentional 

occupational exposure to illicit drugs among employees working in controlled substances laboratories.

Workplace

The police forensic sciences division operated three controlled substances laboratories. Each laboratory 

served a specific geographic region. Employees of the laboratories performed forensic analyses on a 

wide variety of evidence submitted by multiple law enforcement agencies. Because the request focused 

on occupational exposures to illicit drugs, we focused our evaluation on employees who routinely 

handled and/or analyzed suspected controlled substance evidence and those who worked in areas of the 

facility where suspected controlled substances were present. Specifically, we included evidence 

inventory employees, forensic laboratory chemists, and contracted facility environmental services and 

maintenance employees in various portions of the evaluation. 

We conducted first site visits in June 2018 and second site visits in January 2019. At the time of our first 

visit, 24 forensic laboratory chemists, evidence inventory employees, and contracted facility 

environmental services and maintenance employees worked across the three controlled substances 

laboratories. During our second visit to each of these laboratories, forensic laboratory chemists were 

invited to participate in air and handwipe sampling. All noncontractor, nonsupervisory employees were 

members of a union.

To learn more about the workplace, go to Section A in the Supporting Technical Information

Our Approach

We visited each of the three laboratories twice to learn more about potential health concerns and to 

measure exposures. During our site visits, we completed the following activities:

• Observed work processes, work practices, and conditions.

• Measured forensic laboratory chemists’ exposures to cocaine, fentanyl, heroin, and 

methamphetamine in air, on hands, and on surfaces in the forensic chemistry laboratories and in 

office areas.

o There are no occupational exposure limits set by the federal government or consensus 

organizations regarding the result of these types of sampling. Other types of guidelines 

are used for comparison purposes when available. 

• Assessed the fume hoods and the airflow between laboratory areas, hallways, and office areas.
2

• Held confidential medical interviews with all 24 employees in the controlled substances 

laboratories.

• Reviewed relevant records including safety and health program documents, facility floor plans 

and maintenance reports, and laboratory surface sampling results completed prior to our visits.

To learn more about our methods, go to Section B in the Supporting Technical Information

Our Key Findings

Detectable levels of cocaine, fentanyl, heroin, and methamphetamine were in the 

air, on surfaces, and on hands

• Some forensic laboratory chemists had detectable levels of cocaine (11 of 12), fentanyl (4 of 12), 

heroin (9 of 12), and methamphetamine (3 of 12) in their personal air samples. 

• None of the fentanyl levels in air were higher than the occupational exposure limit set by a 

pharmaceutical company. The other controlled substances do not have occupational exposure 

limits.

• Some employees with reportable levels of cocaine, heroin, fentanyl, and methamphetamine in 

their air samples had worked on casework that contained those drugs on the day of sampling.

• We also measured detectable levels of illicit drugs in the air samples of some employees who had 

not worked with those drugs that day. 

• We found detectable levels of cocaine (13 of 13), fentanyl (9 of 13), heroin (13 of 13), and 

methamphetamine (9 of 13) on most employees’ hands before leaving the laboratory at the end 

of the day and those levels were always higher than those measured at the beginning of the day.

• Laboratory benchtop surface samples had detectable levels of cocaine (13 of 13), heroin (13 of 

13), fentanyl (13 of 13), and methamphetamine (12 of 13). 

• Two laboratory bench samples, the keyboard cover sample, one keyboard with no cover, and 

the laboratory shelf sample exceeded a proposed fentanyl-contamination remediation limit. No 

surfaces exceeded a workplace surface limit developed by a pharmaceutical fentanyl 

manufacturer. 

• Seven surfaces, all in the laboratories, exceeded the most common state limit on 

methamphetamine contamination in remediated spaces. 

• Several employees who had positive handwipe samples for methamphetamine, heroin, and 

cocaine had not worked with evidence containing those drugs on the day we did handwipe 

sampling.
3

Work practices and conditions may have contributed to unintentional employee 

exposures to cocaine, fentanyl, heroin, and methamphetamine

• Six of the eight fume hoods in the laboratory bench areas did not have average face velocities 

that met American National Standards Institute (ANSI) and American Industrial Hygiene 

Association (AIHA) guidelines. Most had average face velocities that were faster than guideline 

values, and some were fast enough (above 150 feet per minute) to cause turbulence. 

• The respiratory protection program was not sufficiently specific or instructive to employees and 

resulted in potential exposure control gaps.

• Employees sampled unknown powders on their laboratory benchtop without engineering 

controls or local exhaust ventilation designed to prevent exposure.

• Employees reported that spills of controlled substances did occur. For example, the weigh paper 

could sometimes get caught on the enclosed balances. The current weighing protocols increased 

the risk of controlled substances becoming airborne during transfer from the original packaging 

to the weigh paper and from the weigh paper onto the scales.

• Employees reported cleaning practices such as dry sweeping floors and dry wiping laboratory 

surfaces. These practices can suspend dust and other contaminants in the air. 

• Employees put paper between the laboratory bench and evidence to prevent controlled 

substances contamination of the bench. We observed employees shaking that paper onto the 

ground before disposing it into the waste bin. 

• Employees reported eating or drinking in controlled substances laboratories and inconsistently 

washing hands before eating, drinking, or leaving the laboratory. Some sinks in the laboratories 

were missing soap and/or paper towels.

Interviewed employees did not report any exposure incidents or symptoms that 

could be related to handling cocaine, methamphetamine, or opioids at work in the 

previous three months

• One forensic laboratory chemist reported a brief episode of lightheadedness when 

phencyclidine, known as PCP, was handled in the controlled substances laboratory.

• Review of the Occupational Safety and Health Administration (OSHA) 300 Logs of WorkRelated Injuries and Illnesses from 2013–2017 showed three occasions in which nonspecific 

symptoms were reported associated with handling evidence containing suspected PCP.

Laboratory management improved controls to protect employees from exposure to 

controlled substances between our first and second visit

• Based on recommendations we provided to laboratory management, employees, and employee 

representatives after our first visit, the laboratory made the following improvements:

o Expedited timelines for renovating existing and building new laboratory facilities.
4

o Included all forensic laboratory chemists in the respiratory protection program.

o Provided additional training on how to correctly put on (don) and take off (doff) 

N95 filtering facepiece respirators.

o Fit tested all forensic laboratory chemists qualitatively for the provided N95 filtering 

facepiece respirators.

o Enforced the requirement of eye protection while working in the laboratory spaces.

o Removed all latex gloves from the laboratories.

o Provided laboratory coats with tight-cuffed sleeves to forensic laboratory chemists.

To learn more about our results, go to Section B in the Supporting Technical Information

Our Recommendations 

The Occupational Safety and Health Act requires employers to provide a safe workplace.

Benefits of Improving Workplace Health and Safety:

 Improved worker health and well-being  Enhanced image and reputation 

 Better workplace morale  Superior products, processes, and services

 Easier employee recruiting and retention  May increase overall cost savings

The recommendations below are based on the findings of our evaluation. For each recommendation, 

we list a series of actions you can take to address the issue at your workplace. The actions at the 

beginning of each list are preferable to the ones listed later. The list order is based on a well-accepted 

approach called the “hierarchy of controls.” The hierarchy of controls groups actions by their likely 

effectiveness in reducing or removing hazards. In most cases, the preferred approach is to eliminate 

hazardous materials or processes and install engineering controls to reduce exposure or shield 

employees. Until such controls are in place, or if they are not effective or practical, administrative 

measures and personal protective equipment might be needed. Read more about the hierarchy of 

controls at https://www.cdc.gov/niosh/topics/hierarchy/. 

We encourage the company to use a health and safety committee to discuss our 

recommendations and develop an action plan. Both employee representatives and 

management representatives should be included on the committee. Helpful guidance can be 

found in “Recommended Practices for Safety and Health Programs” at

https://www.osha.gov/shpguidelines/index.html. 
5

Recommendation 1: Reduce employees’ exposures to cocaine, fentanyl, heroin, and 

methamphetamine

Why? We have no indication that the work exposures to cocaine, fentanyl, heroin, and 

methamphetamine that we detected have impacted employees’ health. However, following sound 

occupational health practice, we recommend minimizing workplace exposures to controlled 

substances.

How? At your workplace, we recommend these specific actions:

Improve the availability of enclosed or semi-enclosed ventilated spaces in 

controlled substances laboratories.

• Consult with a ventilation engineer about adding enclosed or semi-enclosed ventilated 

workstations that are designed for handling powders with biologically active ingredients 

when building new facilities or renovating existing facilities. Utilize consensus standards 

published by ANSI/AIHA and ASHRAE when designing new laboratory spaces. 

• Provide ventilated work space in controlled substances laboratories where forensic 

laboratory chemists can handle evidence (e.g., powder hoods, fume hoods) until these 

permanent changes are made.

• Improve the current fume hood maintenance plan. This includes conducting regular 

fume hood maintenance, as well as maintaining records of hood maintenance. 

• Test and record fume hood performance. One method of testing performance is 

measuring hood face velocity when the sash is at working height. Trained staff can 

measure the velocity with a vane or hot wire anemometer. If the average face velocity is 

not within 80–120 feet per minute or if there are areas of low or no airflow at the hood 

face, the hood fan may need to be maintained or the contents of the fume hood may 

need to be reorganized or removed. More information about chemical fume hood 

performance and maintenance can be found in ASHRAE Standard 110 and 

ANSI/AIHA Z9.5. 

• Establish and encourage employees to follow a consistent policy for when to use fume 

hoods or other ventilated enclosures for controlled substance analysis.

Update laboratory protocols to reduce employees’ exposure to controlled 

substances during handling and analysis.

• Eliminate the requirement to take net weights of evidence whenever it is not strictly 

needed for law enforcement purposes or legal proceedings. This will reduce the risk of 

controlled substances becoming airborne during transfer from packaging to scales.
6

• Eliminate the requirement to use enclosed analytical balances for weighing powders. 

This will reduce the risk of spills from weigh paper or boats catching on the sides of the 

balance enclosure during transfer of controlled substances onto these balances.

• Educate all employees on work practices that minimize possible aerosolization of and 

surface contamination with evidence materials. For example, instruct employees to 

refrain from shaking possibly contaminated paper onto the laboratory bench or ground 

before disposal.

Review and update cleaning protocols to keep laboratory surfaces as free 

as practicable of contaminants.

• Use wet cleaning methods or a vacuum equipped with a high efficiency particulate air 

filter for cleaning contaminated laboratory surfaces.

• Do not dry sweep or use dry wiping when cleaning laboratory surfaces.

• Provide, at a minimum, annual training to ensure compliance with approved cleaning 

practices.

• Update cleaning protocols as necessary to reflect the most up-to-date research on 

surface cleaning and contaminant removal for drugs commonly found in submitted 

evidence.

Remind all employees to wash their hands before leaving areas where

controlled substances are handled or stored and before eating, drinking, 

smoking, applying cosmetics, or using the bathroom.

• When designing new laboratories or renovating existing laboratories, include in the 

design handwashing antechambers that are separated from the controlled substances 

laboratory to limit cross-contamination of the handwashing area. The sinks should be 

touchless: either foot or sensor activated. 

• Educate employees about the importance of handwashing to remove contaminants 

from their hands and reduce the risk of absorbing the contaminants into the body. 

Handwashing should last 20 seconds at minimum. 

• Ensure that all handwashing stations are always stocked with soap and disposable paper 

towels. Provide hands-free soap and water dispensers at these handwashing stations 

whenever possible to avoid cross-contamination of handwashing areas.

• Do not use hand sanitizers or bleach solutions to clean skin potentially contaminated 

with fentanyl, although we did not observe employees do this during our visits. 

• Offer smoking cessation programs at no cost to employees. Encourage employees who 

smoke to participate in smoking cessation programs.
7

Remind employees that eating, drinking, or storing food or drinks in areas 

where controlled substances are handled or stored is prohibited.

Encourage employees with possible work-related health concerns to talk 

to their healthcare providers about their workplace exposures to controlled 

substances.

Review and update personal protective equipment plans for employees 

working in areas where controlled substances are handled or stored.

• Improve the facility respiratory protection program:

o Update the health and safety program manual with clear instructions for when 

filtering facepiece respirators are required.

 Currently some instruction has been provided to employees via the 

health and safety program manual and separate email(s).

 Particulate filtering facepiece respirators are recommended for work tasks 

likely to produce aerosolized powders or small particles in the absence of 

appropriate engineering controls, such as ventilation. 

o Provide adequate supplies of disposable filtering facepiece respirators so 

employees do not have to reuse these respirators.

o Improve respirator training and provide annual refresher training (e.g., proper 

donning, doffing, strap placement).

o Ensure that employees undergo medical evaluation and clearance prior to initial 

respirator use and at least annually afterwards. Encourage employees to report 

any symptoms experienced while wearing a respirator to a medical provider and 

the respiratory protection program manager.

o Perform quantitative fit testing because it provides an objective measure of 

respirator fit.

o Use odor or flavor challenges for qualitative fit testing rather than irritant smoke. 

An alternative to qualitative fit testing would be quantitative fit testing. More 

information about qualitative fit testing can be found in the ANSI/AIHA/ASSP 

Z88.10-2010 Respirator Fit Testing Method Standard and in the OSHA 

Respiratory Protection Standard 29 CFR 1910.134 Appendix A.

o Determine if half-mask elastomeric respirators are required for specific tasks. If 

so, ensure that these respirators are properly cleaned, maintained, and stored and 

that the appropriate respirator cartridges are always changed when necessary. In 
8

addition, ensure that employees are medically cleared, appropriately fit tested, 

and properly trained for this type of respirator.

o Clarify respiratory protection program responsibilities for contracted employees. 

• Require forensic laboratory chemists to turn in their laboratory coats for regular 

laundering. This should occur at least weekly. Ensure appropriately sized, clean 

replacement laboratory coats are always available for employees to use while laundering 

other coats.

• Require used laboratory coats to remain in laboratory spaces on a designated hook or 

rack. Advise employees to refrain from bringing used coats into nonlaboratory office 

spaces. 

• Require all employees working in the central receiving area to wear disposable nitrile 

gloves when handling packaged evidence.

Recommendation 2: Improve communication between employees, management, 

and submitting law enforcement agencies

Why? Employees’ health can be affected by a perceived lack of response to concerns, especially if 

employees believe that an exposure is hazardous. We identified several communication issues 

between employees, employees and management, and management and submitting agencies during 

our evaluation.

How? At your workplace, we recommend these specific actions:

Work with forensic laboratory chemists to establish effective ways for 

them to communicate to nearby employees about the suspected types of 

controlled substances being analyzed.

Provide clear communication to employees about new or revised policies 

or procedures well in advance of implementation whenever possible.

Work with submitting agencies to improve adherence to submission 

guidelines to ensure controlled substances are consistently packaged 

according to guidelines.

• Remind evidence inventory employees to ask the representative from the submitting 

agency to repackage evidence if guidelines are not met. Tell employees to reject evidence 

that is not safely packaged according to guidelines.
9

Recommendation 3: Address other health and safety issues we identified during 

our evaluation

Why? A workplace can have multiple health hazards that cause worker illness or injury. Similar to the 

ones identified above, these hazards can potentially cause serious health symptoms, lower morale and 

quality of life for your employees, and increase costs to your agency. We saw the following potential 

issues at your workplace: 

• Employees reported uncertainty about how to use the naloxone kits available in the laboratory 

facilities in the event of an emergency.

• The eyewash station in one of the controlled substances laboratories was inadequate for use in 

the event of an emergency because it lacked a safe and continuous water source.

• The emergency shower in one of the controlled substances laboratories was blocked.

• Employees reported indoor environmental quality concerns, including temperature and air 

quality concerns. 

Although these hazards were not the focus of our evaluation, they could cause harm to your workers’ 

health and safety and should be addressed.

How? At your workplace, we recommend these specific actions:

Provide hands-on naloxone use training to employees with a training 

version of the naloxone delivery device.

• Information on the use of naloxone is available from CDC’s Opioid Overdose webpage 

at https://www.cdc.gov/drugoverdose/index.html. 

• Further information about workplace naloxone use programs is available at 

https://www.cdc.gov/niosh/docs/2019-101/pdfs/2019-101.pdf. 

Ensure that all eyewash stations in laboratory facilities meet the 

ANSI Z358.1-2014: Emergency Eyewash and Shower Standard.

• Ensure portable or plumbed eyewash stations can provide clean water at 0.4 gallons per 

minute at 30 pounds per square inch for at least 15 minutes. 

• Test eyewash stations and safety showers weekly. 

• Further information about the impact of eyewash maintenance is available at 

https://www.osha.gov/Publications/OSHA3818.pdf. 
10

Ensure that all emergency showers in laboratory facilities are easily 

accessible for use in the event of an emergency.

Start a formal indoor environmental quality management program.

• The basic elements of a good indoor environmental quality management plan include 

the following:

o Work with facility maintenance representatives to ensure proper operation and 

maintenance of heating, ventilation, and air conditioning systems.

o Provide effective and timely communication with employees about indoor 

environmental quality issues, ideally before they arise.

o Educate employees about their responsibilities regarding indoor environmental 

quality.

o Continue to proactively address issues that can affect indoor environmental 

quality (e.g., prompt remediation of areas of water incursion by knowledgeable 

personnel).

• Further information is available at https://www.cdc.gov/niosh/topics/indoorenv/. 
Supporting Technical Information

Evaluation of Occupational Exposures to Illicit Drugs 

at Controlled Substances Laboratories

HHE Report No. 2018-0090-3366

January 2020
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A-1

Section A: Workplace Information

Building

Each of the three controlled substances laboratories was housed in a larger building with other law 

enforcement or forensic science activities.

• Laboratory A became operational in 2006 and was designed to be dedicated laboratory space. 

• Laboratory B became operational in 2012 and was designed to be dedicated laboratory space.

• Laboratory C was in a retrofitted space in a police barracks building that was built in the 1960s 

or 1970s. In the 1990s, a portion of the building was renovated into the laboratory space now 

occupied by Laboratory C.

Employee Information

• In total, 24 forensic laboratory chemists (chemists), evidence inventory employees, and 

contracted facility environmental services and maintenance staff were working across the three 

laboratories at the time of our first visit in June 2018. All noncontractor, nonsupervisory 

employees were members of a union.

• Each laboratory operated a single shift Monday through Friday, and employees worked 

8–10 hours per day. Overtime hours were available for chemists but were not mandatory. 

The length of the workweek ranged from 4–6 days depending on each employee’s schedule.

• The median age of employees was 36.5 years (range: 23–64 years).

• The median job tenure was 6 years (range: 3 weeks–27 years).

Process Description

• Suspected illicit drug evidence collected by law enforcement agencies was brought to the 

facilities’ central receiving areas by submitting agency representatives. 

• Evidence inventory employees evaluated the packaged evidence in the facilities’ central receiving 

areas to ensure that it was packaged according to facility requirements. Evidence, in most cases, 

had to be in sealed packages with accompanying submission paperwork. Evidence inventory 

employees were not to accept needles, except in very limited circumstances with prior approval 

from forensic sciences division management.

• Inappropriately packaged evidence was rejected, and submitting agencies were advised on how 

to repackage the evidence for submission.

• Submitted evidence came in a wide variety of physical forms and could include powders, 

crystals, plants and other organic matter, pills, capsules, liquids, impregnated strips or paper, and 
A-2

drug paraphernalia. The chemists received a description of the evidence from the submitting 

law enforcement agent with the suspected contents. 

• Appropriately packaged evidence was logged in by evidence inventory officers, and suspected 

illicit drug evidence was assigned to a chemist for analysis. The evidence was kept in the drug 

vault until the chemist collected it for analysis.

• Chemists analyzed suspected illicit drug evidence in the controlled substances laboratory. The 

specific types of analyses performed were dictated by the evidence being evaluated. In general, 

chemists visually inspected the evidence packaging and contents, measured gross weights that 

included the packaging materials, measured net weights without the packaging materials before 

and after taking a portion for analysis, and performed a minimum of two tests to confirm the 

identity of evidence. Most drugs underwent colorimetric testing, followed by extraction and gas 

chromatography-mass spectrometry, infrared spectroscopy, or microscopic analysis.

• Chemists summarized their methods and the results of their analyses in a final report. These 

reports were written on a computer either in the controlled substances laboratory or in office 

areas outside of the laboratory.

• After completing the analysis, the chemists repackaged the evidence and returned it to the 

central receiving area.

• Evidence inventory employees documented the returned, repackaged evidence and notified the 

submitting agency that the evidence was ready to be returned to them.

• State police evidence was returned to the central receiving area of Laboratory A for destruction 

once a case was closed. In these situations, law enforcement officers, evidence inventory 

employees, and/or other forensic sciences division employees would take the evidence to a 

nearby facility for incineration.

• According to interviewed evidence inventory employees, the central receiving area received up 

to 400 cases per week, with as many as 130 of these cases suspected to involve cocaine or 

opioids.
B-1

Section B: Methods, Results, and Discussion

Our objectives were as follows: 

• Evaluate the potential for and routes of exposure to cocaine, fentanyl, heroin, and 

methamphetamine among chemists working in the controlled substances laboratories. 

• Evaluate the prevalence of work-related symptoms among employees in the controlled 

substances laboratories and identify factors that may be contributing to these health effects.

Identify controls to protect employees in the controlled substances laboratories from exposure to 

controlled substances.

Methods: Health and Safety Program and Document Review

We reviewed the following safety and health program documents:

• Forensic sciences division health and safety manual, dated March 2018

• Central receiving unit and controlled substances laboratory standard operating procedures 

manuals, dated March 2018

• Controlled substances laboratory training manual, dated March 2018

• Fentanyl safety communications sent to controlled substances laboratory personnel in 

December 2017

• Naloxone use training, undated

• Written respiratory protection program, dated March 2018

• OSHA Log for the forensic sciences division for the period of January 1, 2013, to 

December 31, 2017 

Facility floor plans, reports of recent maintenance performed on controlled substances laboratory fume 

hoods, and surface sampling results, performed in each of the three laboratories in 2018 to evaluate for 

surface contamination in the laboratories

Results: Health and Safety Program and Document Review

The forensic sciences division health and safety manual stated, “there shall be no food or beverages 

stored, carried through, or eaten within laboratory space or other areas of the laboratory building where 

hazardous materials are stored or generated.” The manual also instructed employees to “avoid touching 

all clean surfaces with contaminated hands, gloves, or other contaminated personal protective

equipment (PPE). This includes general use items (e.g., computers, instrument control panels, etc.) in 

the laboratory areas.” The manual further directed them to “wash hands after removing gloves and 

before eating, drinking, applying cosmetics or lip balm, applying contact lenses or conducting any 

activities outside of laboratory space.” This manual also said that access to safety showers should not be 

blocked and “the immediate area beneath the shower kept free from obstructions.”
B-2

The written respiratory protection program applies to employees who are required to wear air-purifying 

respirators and atmosphere-supplying respirators and does not apply to contractors. 

The program manual also stated that employees shall use respiratory protection in the following cases:

• In areas where known contaminant levels require the use of respiratory protection.

• In areas where contaminant levels may be created without warning (e.g., emergency purposes 

such as hazardous material spill responses) and pose a respiratory hazard. 

• In suspect areas or performing operations suspected of being hazardous but for which adequate 

sampling data has not been obtained.

Information provided to employees concerning use of filtering facepiece respirators was not consistent. 

In the health and safety manual, respirator use was noted to be voluntary (i.e., not required) for most 

employees and involved the use of a filtering facepiece respirator. During our first visit, chemists and 

evidence inventory employees were not enrolled in the facility’s respiratory protection program. 

However, management representatives regarded respiratory use mandatory in forensic chemistry 

laboratories per instructions provided to chemists via email: “Chemists must wear a mask (specific for 

filtering small particles) when working with items that contain dangerous powder substances.” Neither 

the manual nor separate management instructions specified whether laboratory employees would be 

provided with Appendix D as required by the OSHA respiratory protection standard for voluntary use 

respiratory protection programs.

Regarding other PPE-related information, the forensic sciences division health and safety manual 

advised that laboratory employees “wear the appropriate eye protection when there is a reasonable 

probability of impact, splash, or other potential exposure to the eyes.” In addition, email 

communication from management representatives regarding PPE use in controlled substances 

laboratories advised that “chemists must wear a lab coat at all times during analysis – lab coats need to 

be switched out on a weekly basis for cleaning.” 

The naloxone training we reviewed was a presentation that focused on administration of naloxone by 

law enforcement officers. It did not appear to include hands-on training on how to properly use the 

type of naloxone kits available in the controlled substances laboratories or discuss administration of 

naloxone by chemists or evidence inventory employees.

Review of OSHA 300 Logs for the period of January 1, 2013, to December 31, 2017, showed a total of 

18 reports of injuries and illnesses among employees in the forensic sciences division. These included 

12 reports of injuries, 1 report of noise exposure, 1 report of heat-related illness, and 1 report of 

exposure to fiberglass. In 2016, an evidence inventory employee reported symptoms that included 

dizziness, headaches, nausea, and chest tightness while handling evidence containing suspected PCP on 

three separate occasions. During one of these incidents, this evidence inventory employee reported 

wearing “an AVON mask and respirator” when the symptoms began.

Review of the results of surface sampling performed in each of the three controlled substances 

laboratories in 2018 demonstrated residual levels of laboratory surface contamination with opioids and 

other controlled substances. The controlled substances present in highest levels on surfaces were 
B-3

cocaine and heroin. We did not explicitly compare our quantitative surface results with the samples 

taken in 2018 because they were taken using different sampling methods. However, we used these 

results, along with drugs commonly found in casework, to determine which analytes we measured on 

surfaces and hands and in air.

Methods: Observations of Work Processes, Practices, and Conditions

We evaluated the following in all three controlled substances laboratories:

• Workplace conditions and work processes and practices

o Spot carbon dioxide concentrations in the laboratories

• Fume hood face velocity and airflow between laboratory areas and common areas using 

ventilation smoke

• Employee use of PPE

Results: Observations of Work Processes, Practices, and Conditions 

Workplace Conditions and Work Practices

In all laboratories, each chemist was assigned his or her own dedicated workstation in the laboratory. 

A workstation consisted of laboratory benchtop space, one or more scales, a laptop dock, keyboard, 

mouse, and monitor. Each chemist had equipment for sampling and sample preparation, colorimetric 

testing, and microscopy. 

As required by laboratory protocols, chemists emptied the container of evidence they were analyzing 

and weighed the contents to record a net weight. Depending on the amount and type of controlled 

substance evaluated, the net weight might have been necessary for charging or prosecuting suspected 

criminals. Not all criminal charges required the measurement of net weights. At the time of our 

evaluation, when the chemist suspected the evidence contained opioids, chemists were guided to 

analyze the sample before measuring the net weight of the evidence. Depending on the outcome of the 

testing, the chemists were allowed to decline to measure the net weight of the evidence if it contained 

fentanyl or fentanyl analogues. We did not observe chemists forego measuring the net weight of 

sampled evidence. We also observed several instances of suspected evidence falling onto the workbench 

and the 

balance plate. 

Staff cleaned benchtops and equipment using methanol at all three laboratories. At Laboratory A, the 

benchtops appeared worn and discolored at all chemists’ work locations. The laboratory benchtops 

appeared to be deteriorating. This was not the case at Laboratories B and C where the laboratory 

benchtops did not appear to be abnormally worn. 

Several times during our site visit, the suspected chemical identity—from either the chemists’ 

professional prediction or officers’ paperwork— did not match the ultimate outcome of analysis. These 

incidents demonstrate that using suspected contents to determine which workplace exposure controls 

to use (PPE, ventilation, declining to take net weights) could lead to insufficient exposure protections. 
B-4

At the time of our first visit, all three laboratories had at least one naloxone kit available for use in the 

event of an opioid-related emergency. Several of the naloxone kits were expired at the time of this visit. 

One laboratory had two types of naloxone kits available, and employees expressed uncertainty about 

how to use one of the kits. At the time of our second visit in January 2019, expired naloxone kits had 

been replaced, and only one type of naloxone kit was available in the laboratories.

During both of our visits, the floor under the safety shower in one of the laboratories was blocked by 

laboratory supplies. This laboratory also did not have a functional, continuous flow eyewash station 

connected to a water source that was considered safe for emergency eyewash use. Instead, a two-bottle 

eyewash station was available for use in the event of an emergency. Several replacement eyewash station 

bottles were also available if needed.

In Laboratory A, local exhaust ventilation (LEV) was installed at each chemist’s workstation. The 

moveable exhaust hoods with semiflexible duct work were not used during our visit, and employees said 

they did not generally use them.

At Laboratories A and B, we measured spot carbon dioxide concentrations at 512 parts per million 

(ppm) or lower during our second site visit. According to maintenance staff, these laboratories are 

ventilated using a single pass system, without recirculation. At Laboratory C, we measured carbon 

dioxide concentrations that exceeded 1,130 ppm by the end of the workday. ANSI/ASHRAE state that 

general dilution ventilation cannot be designed to achieve contaminant control. They further 

recommend that air exchange rates should range from 4 to 10 air changes per hour in laboratories 

depending on the general and local exhaust ventilation design [ANSI/AIHA 2012]. Although we did 

not calculate air changes per hour in the laboratories, carbon dioxide concentrations would be lower if 

Laboratory C had been ventilated at the rates outlined by ANSI/AIHA.

Fume Hood Performance and Use 

All three laboratories had at least two fume hoods. Extraction solvents, other chemicals, and liquid 

chemical waste were stored in bulk in the hoods. Some of the fume hoods contained large amounts of 

material and waste, preventing their use for evidence handling. Employees used the fume hoods when 

dispensing solvents. One employee reported sampling suspected carfentanil (a synthetic opioid) in the 

laboratory fume hood, but we did not observe any employees using the hoods to handle, sample, or 

weigh evidence. 

Laboratory A had four fume hoods, one of which met the ANSI/AIHA laboratory ventilation 

standards of an average face velocity of 80–120 feet per minute (fpm) [ANSI/AIHA 2012]. Two of the 

Laboratory A hoods operated at a velocity lower than this range (65 fpm and 63 fpm), and one operated 

higher than this range (144 fpm). Laboratory B had two ventilation hoods in the laboratory bench area. 

One of the hoods conformed to the ANSI/AIHA standard, and the average face velocity of the other 

hood was 140 fpm. In Laboratory C, the average face velocities of each hood were not within the 

standard range: both were higher (180 fpm and 130 fpm). Lower velocities (60–80 fpm) require ideal 

laboratory conditions and hoods with excellent containment characteristics to be effective 

[ANSI/AIHA 2012]. Although hoods with average face velocities between 120 and 150 fpm can be 

effective at containment, operating costs are very high and not necessary. Velocities above 150 fpm can 

cause turbulent flow [ANSI/AIHA 2012]. Laboratory C hood face velocities had previously been 
B-5

measured and certified by a contractor but were outdated at the time of site visit. The maintenance staff 

at Laboratory C maintained the hood fan and belts but did not take face velocity measurements or 

certify the hood’s performance.

When we visually assessed airflow between common areas and laboratory spaces, we expected to see air 

flowing from hallways and offices into laboratories spaces, with few exceptions. At Laboratory A, air

flowed into the laboratory from the antechamber to the laboratory and into the hallway. At Laboratory 

B, air flowed from both laboratory antechambers into the hallways. At Laboratory C, air flowed from 

the instrument room into the hallway but flowed into the lab from the hallways at the other two doors. 

Employee Use of Personal Protective Equipment

During our first visit to the laboratories, we observed limited use of eye protection (e.g., safety glasses, 

safety goggles, or side shields on prescription eyeglasses) and frequent use of nitrile gloves. All chemists 

wore gloves when handling unpackaged evidence. All but one laboratory stocked exclusively nitrile 

gloves in the laboratory. One laboratory had latex gloves available for employees to use at the time of 

our first visit but had removed them from their storage area by the time of our second visit. 

Employees wore laboratory coats when in the laboratory. Some employees only wore coats when 

analyzing evidence in the laboratory. Employees reported that correctly sized, clean laboratory coats 

were sometimes not available. Some employees reported that loose cuffs on the coats caught on 

laboratory materials. When leaving the laboratory, most employees kept their coats on the back of their 

chairs in the laboratory. Some hung them up on the coat rack. At one lab, the coats were kept in the 

office space because they would fall off the coat rack.

Chemists typically changed gloves between cases, and sometimes between items within a case. We 

observed chemists using workstation keyboards both with and without gloves. This occurred both 

between and after cases, and without cleaning the keyboard. Additionally, chemists would don and doff 

their safety glasses with gloved hands. We also observed one employee wash a plate used for eating at 

the laboratory antechamber sink. Some laboratory sinks in antechambers were not equipped with soap 

and/or paper towels. 

We observed some employees wearing N95 filtering facepiece respirators when analyzing cases and 

handling unknown powders. We observed that these respirators were generally not worn correctly 

during the first site visit. Often the straps were not placed correctly. At the time of our first visit, none 

of the chemists or evidence inventory employees had been fit tested for the provided N95 respirators or 

included in the respiratory protection program. 

Between our two visits, laboratory management made several PPE-related changes: 

• Included all chemists in the respiratory protection program.

• Provided additional training on how to correctly don and doff N95 respirators. 

• Fit tested all chemists qualitatively for the provided N95 respirators using irritant smoke.

• Enforced the requirement of eye protection in the laboratory spaces.

• Provided laboratory coats with tight-cuffed sleeves to staff.
B-6

• Removed all latex gloves from the laboratories.

At the time of our second site visit, we observed the impact of these changes: 

• Chemists who wore N95 respirators wore them correctly, and most people working with 

powders suspected to be opioids chose to wear N95 respirators.

• All chemists always wore eye protection while working on casework in the controlled substances 

laboratories, but some chemists wearing personal prescription glasses needed side shields.

• Almost all chemists who wanted tight-cuffed laboratory coats used them while working in the 

controlled substances laboratories. One was awaiting a coat of the correct size and pocket 

location. 

• No latex gloves were available for use in any of the controlled substances laboratories.

In addition to the changes above, chemists had been provided with air-purifying elastomeric half-mask 

respirators with GME P100 Multigas combination cartridges for organic vapor, acid gases, ammonia, 

methylamine, formaldehyde, and hydrogen fluoride. During both visits, we observed that respirators, 

both the N95 filtering facepiece and air-purifying elastomeric half-mask, were not stored correctly. Used 

N95 filtering facepiece respirators were kept in drawers or on shelves, not in sealed bags. Employees 

were not sure how often they should discard their N95 filtering facepiece respirator and replace it with a 

new one. Air-purifying elastomeric half-mask respirators with attached cartridges were generally not 

kept in sealed bags or cleaned between uses. Employees did not know when they should change the airpurifying cartridges on the air-purifying elastomeric half-mask respirators and had not changed them in 

the approximately one month since receiving the respirator. We observed one employee use their airpurifying elastomeric half-mask respirator. A chemist used it while handling powder containing 

suspected opioids on their laboratory bench. In discussion with chemists, they were not aware when 

each type of respirator (N95 filtering facepiece or air-purifying elastomeric half mask) was required or 

recommended to be used. 

Contracted facility environmental services employees wore N95 filtering facepiece respirators and 

gloves when entering the laboratory to empty trash cans. During both site visits, some chemists would 

work with N95 respirators around their necks between cases.

Methods: Exposure Assessment

Air Sampling

Among 12 chemists, we collected full-shift personal air samples for cocaine, fentanyl, heroin, and 

methamphetamine using 25-millimeter glass fiber filters in conductive cassettes attached to pumps 

drawing air at two liters per minute. A series of four or five samples were collected on each employee 

(sample duration ranged from 47 to 127 minutes). We calculated a time weighted average (TWA) 

concentration using the employee’s individual sample data for each of the four target drugs. We used 

the reporting limit divided by the square root of 2 to impute censored data for individual samples when 

calculating the geometric mean of the full-shift TWA exposures [Hornung and Reed 1990]. For one 

employee, pump failure led to loss of two samples, so the remaining two samples were used to calculate 

a partial-shift exposure. 
B-7

All samples (air, handwipe, and surface) were stored and shipped cold to the analytical laboratory. At 

the laboratory, the samples were extracted in the cassette to account for wall losses using a water and 

methanol mixture. The sample was analyzed via ultrahigh performance liquid chromatography with 

triple quadrupole mass spectroscopy detection. The reporting limit was 1 nanogram (ng) per sample for 

each of the four drugs analyzed.

Chemists provided the list of the cases they worked on during our visits, and management provided the 

list of the confirmed drugs in each of those cases. For each drug, we compared the personal full-shift air 

concentrations for those who worked with evidence confirmed to contain the drug to the 

concentrations for those who did not work on cases containing that drug. We compared the air 

concentrations of the two groups using a one-tailed Mann – Whitney U test with significance 

established at α = 0.05.

Handwipe Sampling

We took preshift and postshift handwipe samples of 13 chemists for cocaine, fentanyl, heroin, and 

methamphetamine. Participants were asked to wash hands thoroughly before preshift handwipe 

sampling to remove drug contamination from nonoccupational sources. Employees were allowed to 

wash their hands as they normally would during their work shift. Postshift handwipe samples were 

taken when the employee ended work in the lab, before they washed their hands for the last time. For 

each employee, we sampled the palm side of both hands using a swab wetted with methanol. In 

addition to the handwipe samples, we also sampled the palm side of both gloved hands for three 

employees at the end of a case. This was in addition to the handwipe samples.

The fraction of the total amount of each analyte that was collected (recovery) during handwipe sampling 

has not been characterized. The same NIOSH investigator took all handwipe samples.

Surface Sampling

We sampled 22 surfaces across all three laboratories for cocaine, fentanyl, heroin, and 

methamphetamine using a swab wetted with methanol. The sample area was 100 square centimeters 

(cm2) (using a template) on all surfaces, except keyboards and gloved hands. We took a sample of 

approximately 100 cm2 on keyboard surfaces. 

Average surface recovery for the materials comprising laboratory benchtops, office desktops, and scale 

plates exceeded 70% using the swabs [Bureau Veritas North America 2018]. For other surfaces, like 

keyboards and gloved hands, the recovery range for these swabs has not been characterized. 

There are no occupational standards regarding limits on surfaces for cocaine, fentanyl, heroin, and 

methamphetamine set by the federal government or consensus organizations. Some states have 

developed guidelines for remediation of methamphetamine-contaminated spaces, like clandestine drug 

labs. The U.S. Environmental Protection Agency (EPA) has developed voluntary methamphetamine 

laboratory cleanup protocols. According to the EPA, 25 states have developed recommended or 

required standards for methamphetamine remediation as of 2013. The state standards range from 

0.05 to 1.5 micrograms (μg)/100 cm2, the most common being 0.1 μg/100 cm2 [EPA 2013]. 

Additionally, one company that manufactures fentanyl has developed a workplace surface 

contamination limit of 1 μg fentanyl/100 cm2 in their facilities [Van Nimmen and Veulemans 2004]. 
B-8

A county health department proposed a limit of 0.1 μg/100 cm2 for remediation of fentanylcontaminated properties where the general population might occupy [Rosen 2018]. One state has added 

fentanyl remediation standards to complement existing methamphetamine contamination remediation 

legislation: fentanyl should not be detectable in properties post-remediation in this state [California 

Legislature 2019]. The detection limits expected are not explicitly stated in the legislation [California 

Legislature 2019].

Results: Exposure Assessment

Air Sampling

Of the 12 chemists who participated in air sampling, 11 had 4–5 consecutive samples included in a 

full-shift sample (423 to 493 minutes). However, for one chemist, two samples were not analyzed 

because of pump failure, so the sample time consisted of only about half of the chemist’s shift 

(223 minutes). The four analytes were not detected (reporting limit 1 ng) in the field blank filters. 

Minimum, maximum, and geometric mean full-shift TWA exposures are in Table C1. Table C2 contains 

the TWA full-shift concentrations for all the participating chemists. None of the full-shift fentanyl 

exposures exceeded an occupational exposure limit established by a fentanyl manufacturing company of 

0.1 μg/cubic meter (m3) [Van Nimmen et al. 2006]. The other analytes, cocaine, heroin, and 

methamphetamine, do not have established occupational exposure limits. Of the 12 chemists, 

10 handled cocaine-containing evidence, 10 handled fentanyl-containing evidence, 8 handled heroincontaining evidence, and 3 handled methamphetamine-containing evidence. We took eight field blank 

samples across the 3 days of sampling to account for any sample contamination during transport; none 

were found to contain reportable drugs during analysis.

The average personal air cocaine, fentanyl, and heroin concentrations were higher among employees 

who handled casework confirmed to contain that respective drug. For cocaine (P = 0.03) the air 

concentrations were statistically significantly higher for employees who worked on casework confirmed 

to contain the drug compared with the personal air concentrations for those who did not. 

We looked at the relationships between confirmed substances in employees’ casework and the results of 

their personal air samples. One employee who did not work on casework containing cocaine still had 

reportable concentrations of cocaine in their personal air samples. The same is true for three employees 

who did not work on heroin-containing cases and two employees who did not work on 

methamphetamine-containing cases. Conversely, five employees who worked on casework containing 

cocaine did not have reportable cocaine in their personal air samples. Again, the same is true for one 

person who handled casework containing heroin and three people who handled casework containing 

methamphetamine.

Handwipe Sampling

Table C3 shows handwipe sampling results for employees at the three lab locations. All 13 postshift 

handwipe samples had reportable amounts of cocaine (range: 19–2,600 ng/swab) compared to 

9 preshift handwipe samples (range: 1.1–19 ng/swab). For fentanyl, 9 of the 13 postshift handwipe 

samples had reportable amounts, ranging from below the reporting limit of 1 to 11 ng/swab. None of 

the corresponding preshift handwipe samples had reportable fentanyl levels. For heroin, all 13 postshift 
B-9

handwipe samples had reportable amounts (range: 1.1–160 ng/swab) compared to only four preshift 

handwipe samples (range: 1.1–3.5 ng/swab). For methamphetamine, nine postshift handwipe samples 

had reportable amounts (range: 1.1–33 ng/swab), while only one preshift handwipe sample had a 

reportable amount (5.7 ng/swab). Some employees who did not work on evidence confirmed to contain 

cocaine, heroin, and methamphetamine had those drugs on their hands at the end of the day, even 

though most wore gloves: 

• 2 of 2 chemists who did not handle cocaine had reportable levels on their hands

• 4 of 4 chemists who did not handle heroin had reportable levels on their hands

• 5 of 9 chemists who did not handle methamphetamine had reportable levels on their hands

Neither of the two chemists who did not handle fentanyl had reportable levels on their hands.

All of the reportable, postshift handwipe samples we collected had higher amounts of a given analyte 

than their matching, preshift handwipe samples. There are no occupational exposure limits established 

to use for comparisons with this type of sampling.

Surface Sampling

Table C4 shows surface wipe sampling results at the three laboratory locations. One surface sample was 

collected at a workstation in which the keyboard had a keyboard cover. The keyboard cover had higher 

amounts of all analytes as compared to the keyboard underneath. The keyboard cover also had higher 

amounts of all analytes than the four keyboards without covers (or with nonremovable covers) and 

some of the highest overall surface concentrations we measured. We did not observe chemists with 

keyboard covers clean them. At least one keyboard cover was stored in the same drawer as an airpurifying elastomeric half-mask respirator and gloves.

All three surface samples collected on keyboards had reportable concentrations of cocaine 

(range: 0.027–4.0 μg/100 cm2), heroin (range: 0.0010–0.68 μg/100 cm2), and methamphetamine 

(range: 0.0079–0.046 μg/100 cm2). Two of the three surface samples collected on keyboards had 

reportable concentrations of fentanyl (0.021–0.37 μg/100 cm2).

Of the 13 surface samples collected on lab benches, all had reportable concentrations of cocaine 

(range: 0.075–5.0 μg/100 cm2), fentanyl (range: 0.0012–0.37 μg/100 cm2), and heroin 

(range: 0.0050–0.23 μg/100 cm2). Twelve had reportable amounts of methamphetamine 

(range: 0.0017–0.45 μg/100 cm2). A surface sample collected from a dusty shelf in the laboratory had 

reportable concentrations of cocaine (2.9 μg/100 cm2), fentanyl (0.15 μg/100 cm2), heroin 

(4.0 μg/100 cm2), and methamphetamine (0.11 μg/100 cm2). This shelf had higher concentrations of 

analytes compared to most of the other surfaces sampled.

Surface samples collected on the three report desks had lower amounts of analytes as compared to 

other surfaces. One report desk had no reportable concentrations of all four analytes. Another had a 

reportable level of cocaine (0.014 μg/100 cm2) and not reportable concentrations for the remaining 

analytes. Another report desk had reportable concentrations of cocaine (0.045 μg/100 cm2), heroin 

(0.0029 μg/100 cm2), and methamphetamine (0.0092 μg/100 cm2), with not reportable concentrations 

of fentanyl. 
B-10

None of the report writing area samples or keyboards exceeded the commonly used state or local 

guideline of 0.1 μg methamphetamine/100 cm2 [EPA 2013]. The keyboard cover sample, the lab shelf 

sample, and 5 of the 13 laboratory bench samples exceeded this guideline. The EPA notes that these 

standards are thought to be health-protective, despite being developed with feasibility and available 

technology in mind [Colorado Department of Public Health and Environment 2005; EPA 2013].

Of the surfaces sampled, none of the report writing area samples exceeded the fentanyl contamination 

limit of 0.1 μg/100 cm2, as proposed by the county health department. Two of the laboratory bench 

samples, the keyboard cover sample, one of the keyboards with no cover, and the lab shelf sample 

exceeded this proposed limit. The draft guideline developed by the local health department was done 

with technological feasibility in mind. The limit was established based on the common limit of detection 

for surface samples, making site clearance contingent upon nondetectable fentanyl concentrations for all 

samples taken [Rosen 2018]. None of the surface samples exceeded an internal fentanyl contamination 

limit of 1 μg/100 cm2 as set by a manufacturer for their facilities. 

One of the seven swab field blanks had a reportable level of 1.3 ng/swab (0.0013 μg/swab) of cocaine 

in the sample. No other analytes were reportable in this sample (reporting limit 1 ng). None of the other 

field blank samples contained reportable levels of the four analytes. We blank-corrected the hand and 

surface wipe samples taken on the day this field blank was taken.

Methods: Employee Health Assessment

Confidential Medical Interviews

During our first visit in June 2018, we invited all 24 chemists, evidence inventory employees, and 

contracted facility environmental services and maintenance staff working across the three laboratories 

to participate in confidential medical interviews. Interviews covered basic demographics, work history 

and practices, training, health and safety concerns, and possible work-related health effects. We asked 

questions specifically about work practices related to handling cases suspected to contain cocaine or 

opioids. We focused on these substances because the results of the 2018 surface sampling demonstrated 

higher levels of cocaine and heroin on surfaces than other controlled substances, and the request 

included concerns about exposures to fentanyl or fentanyl analogues. We asked interviewed employees 

whether they had experienced any symptoms or health effects that they felt were related to handling 

cocaine, methamphetamine, or opioids at work. Known health effects of severe cocaine, fentanyl, 

heroin, and methamphetamine toxicity are shown in Table C5.

Results: Employee Health Assessment 

Confidential Medical Interviews

All 24 employees working across the three laboratories at the time of our first visit participated in 

confidential medical interviews. This included 13 chemists, 7 evidence inventory employees, and 

4 contracted facility environmental services and maintenance employees. Table C6 shows the locations 

within the facilities where these employees reported working. Among 13 interviewed chemists, the 

median reported time spent in the controlled substances laboratory was 5.5 hours (range: 1–7.5 hours). 

Five of seven evidence inventory employees reported spending no work time in the controlled 

substance laboratories; the other two reported spending 10 minutes–1 hour each day. Three of four 
B-11

contracted environmental services and maintenance employees reported spending 10–30 minutes of 

their daily work hours in the controlled substance laboratories.

The median number of cases analyzed by interviewed chemists in the controlled substances laboratory 

was reported to be 17.5 cases per week (range: 0–30). Of these cases, the median number suspected to 

be cocaine or opioids was 10.5 cases per week (range: 0–24). Of note, three interviewed chemists were 

in training at the time of our visit. As a result, they reported analyzing primarily training cases under the 

supervision of another more experienced chemist. Most interviewed chemists reported only rarely 

processing cases under a fume hood, but one reported using a hood up to four times a week for 

casework. Reported reasons for choosing to use a hood for casework included cases that require the use 

of volatile reagents for analysis, handling cases with a strong odor or those containing PCP, unknown 

liquids, large quantities of unknown powder, cases that could contain carfentanil, and when processing 

pill presses.

We asked about PPE use among the 13 chemists and 7 evidence inventory employees when they 

handled cases involving known or suspected cocaine or opioids in the controlled substances laboratory 

and central receiving area (displayed in Table C7). All 13 interviewed chemists and none of the 

7 evidence inventory employees reported always wearing a laboratory coat. All 13 interviewed chemists 

and 6 evidence inventory employees reported always wearing long pants. All 13 chemists reported 

always wearing nitrile gloves while 6 evidence inventory employees reported sometimes wearing nitrile 

gloves. Use of N95 filtering facepiece respirators was also variable across the two groups, with 

10 chemists reporting sometimes wearing one and 6 evidence inventory employees reporting never 

wearing one. Most chemists (n = 9) and most evidence inventory employees (n = 6) reported never 

wearing safety glasses or goggles.

During interviews, we also asked laboratory employees about other personal work practices. Among the 

13 interviewed chemists, 6 reported laundering their laboratory coats weekly or every 2–3 weeks, 

3 reported laundering monthly, and 4 reported never laundering or only on a seldom basis. Of the seven 

evidence inventory employees, three reported eating, drinking, or storing food or drink in the central 

receiving area daily, and two chemists reported seldomly eating, drinking, or storing food or drink in the 

controlled substances laboratory. The remaining 19 of 24 interviewed employees reported never eating, 

drinking, or storing food or drink in the controlled substances laboratory or central receiving area. 

When asked about handwashing, 19 interviewed employees, including 8 chemists, all 7 evidence 

inventory employees, and all 4 contracted facility environmental services and maintenance staff, 

reported always washing their hands before eating or drinking at work. Of the 13 chemists, 5 reported 

only sometimes washing their hands before eating or drinking at work. In addition, 15 interviewed 

employees, including 8 chemists, 3 evidence inventory employees, and all 4 contracted facility 

environmental services and maintenance staff reported always washing their hands before leaving the 

laboratory.

Table C8 shows the training that interviewed employees reported receiving in certain health and safety 

topics. Most (16–18) of the 20 laboratory employees reported that they had received training on the 

following topics: safe handling of cases involving known or suspected cocaine or opioids, recognition of 

symptoms/signs of opioid intoxication, proper administration of naloxone, safe handling of sharps, and 
B-12

what to do in the event of a sharps injury. None of the four contracted facility environmental services 

and maintenance staff we interviewed reported receiving any training in these topics. All 13 chemists 

reported receiving training on how to properly administer naloxone. 

None of the 24 interviewed employees reported any incidents of direct skin, respiratory, or mucous 

membrane exposure to suspected cocaine or opioids at work in the three months prior to our visit. 

Regarding symptoms, one chemist reported being unsure whether dizziness or lightheadedness 

experienced on two or three occasions while working in the laboratory was related to casework or 

something else. None of the other 23 interviewed employees reported experiencing any symptoms that 

they felt were related to handling cocaine or opioids at work. Another chemist reported feeling 

lightheaded or dizzy when PCP was handled in the controlled substances laboratory. Walking outside of 

the facility for 15–20 minutes typically resulted in resolution of these symptoms. Health effects of 

severe cocaine, fentanyl, heroin, and methamphetamine toxicity are shown in Table C5. None of the 

interviewed employees reported a sharps injury at work in the three months prior to our visit.

All 24 interviewed employees reported participating in facility cleaning. One evidence inventory 

employee reported regularly dry sweeping the central receiving area. Four chemists and two contracted 

facility environmental services and maintenance staff reported regularly dry sweeping the controlled 

substances laboratory. In addition, three contracted facility environmental services and maintenance 

staff reported always wearing nitrile gloves when cleaning in the controlled substances laboratory and 

always using an N95 respirator when removing trash from the controlled substances laboratory.

At the end of our interviews, we asked employees to share additional work-related health and safety 

concerns they had. Seventeen interviewed employees reported no additional concerns. Among the 

remaining seven interviewed employees, additional issues identified included concerns about poorly 

functioning fume hoods and other facility-related indoor environmental quality issues. A few employees 

also expressed concerns about certain drug handling procedures including the requirement to open drug 

packaging in the central receiving area to count contents, perform net weights, use enclosed analytical 

balances, and handle sharps such as needles and razor blades. One employee expressed a desire to have 

cuffed laboratory coats while two employees expressed a desire to improve availability of PPE.

Three interviewed employees also complained about poor communication in general between 

employees, employees and management, and the facility and law enforcement agencies that submit 

evidence for analysis. These included a lack of communication about casework performed by nearby 

chemists in controlled substances laboratories and reports that new safety and health policies and 

procedures were sometimes released and implemented with little or no notice given to employees. 

Another concern expressed was about inconsistent packaging of controlled substances submitted 

for analysis.

Lastly, three employees reported concerns related to the naloxone kits kept in the controlled substances 

laboratory for emergencies. Complaints included inadequate naloxone use training, insufficient numbers 

of available naloxone kits, and failure to replace expired naloxone kits in a timely manner.
B-13

Discussion 

Although employees at the three controlled substance laboratories reported no symptoms associated 

with acute exposures to cocaine, methamphetamine, and opioids, we identified the potential for 

unintentional exposures in the air and on contaminated surfaces and hands. 

Work Practices

Because of the unpredictable form, amount, and contents of incoming evidence, the policy of 

measuring net weights poses a potential risk of hazardous substances exposure to forensic chemists. 

Taking net weights requires extra handling of uncontained evidence: removing substances completely 

from packaging, transferring substances to disposable weighing paper or a weigh dish, and placing this 

into and removing it from a balance. Measuring net weights increases the time the substance spends 

outside of packaging and requires chemists to handle larger amounts of these substances compared to 

the amount needed for analysis. Therefore, measuring net weights creates the opportunity for spills and 

aerosolization that could potentially lead to significant exposure to these drugs. These exposures are less 

likely to occur when measuring gross weights.

The practice of laying a piece of paper between the laboratory bench and the evidence was common at 

all the laboratories. This may be effective at preventing surface contamination but poses a greater risk of 

aerosolizing the evidence being handled, based on our observations. Our observations of employees 

shaking barrier paper after analysis and the barrier paper being emptied from small trash containers into 

the larger waste bin daily may be contributing to employees’ airborne drug exposures. 

Most of the employees who had detectable air samples for a specific drug had handled evidence 

containing that drug. Therefore, working on casework containing a drug appeared to contribute to air 

exposures of that drug. However, this was not universal. For cocaine, heroin, and methamphetamine, 

we found the drugs in the air sample of at least one employee who did not work with casework that 

contained those drugs. We were not able to attribute this to a specific activity or activities. This indicates 

that exposure can potentially occur as a result of adjacent employees’ work or the aerosolization of 

small amounts of environmental contamination during work in the drug labs. Overall, the personal air 

concentrations for those who handled evidence containing specific drugs were higher than those that 

did not personally analyze that drug. 

We found all employees with fentanyl in their postshift handwipe sample had worked with fentanylcontaining evidence. A minority of employees with cocaine and heroin in their handwipe samples had 

not handled casework containing the drug. However, for methamphetamine, 75% of the employees 

whose handwipe sample contained methamphetamine had not handled casework containing 

methamphetamine. These handwipe and surface sample results demonstrate that handling evidence is 

not the only source of potential dermal exposure.

Exposures in Air

Several studies have demonstrated the potential for aerosolization of cocaine and exposures to workers. 

In one evaluation of cocaine exposure among narcotics criminalists processing packages of cocaine, 

researchers found that employees who made small incisions in the packages to take small samples and 

who wore masks (3M Model 9970, discontinued) had lower urinary concentrations of cocaine and 
B-14

cocaine metabolites than those who opened and repackaged evidence or who did not wear respiratory 

protection [Le et al. 1992].

In an evaluation measuring airborne levels of cocaine in forensic laboratories in Spain, cocaine was 

present in all air samples, even on days when there was no cocaine being handled during the sampling 

period. The concentration of cocaine in the air increased considerably (100 times higher) on days when 

cocaine was handled [Armenta et al. 2014]. Cocaine handling consisted of opening, transferring, 

sampling, and resealing evidence packages.

Personal air exposures to cocaine measured among the chemists in our evaluation (NR–0.72 μg/m3, 

with NR meaning not reportable or less than 1 ng per sample) were lower than some previous studies 

of law enforcement and chemists. In simulated cocaine evidence processing, the researchers measured 

concentrations 68–6,400 μg/m3, which is much higher than exposures we measured [Le et al. 1992]. In 

an evaluation of cocaine exposure among crime laboratory employees preparing training aids for 

military working dogs, personal air exposures to cocaine were measured at 29.20–69.94 μg/m3

[Gehlhausen et al. 2003]. These personal air exposures decreased to 11.00–18.09 μg/m3 following 

interventions that included changing procedures, using a laboratory hood during all manufacturing 

functions, fit testing for respirators, and providing more rigorous training on PPE use [Gehlhausen et 

al. 2003]. These employees’ exposures, before and after intervention, were also much higher than 

exposures we measured.

In a previous health hazard evaluation (HHE) evaluating police officers’ exposures to chemicals while 

working inside a drug vault, personal air exposures to cocaine ranged from not detected (minimum 

detection concentration = 0.03 μg/m3) to 12 μg/m3 [NIOSH 2011]. Some of these personal air 

sampling results may have overestimated the actual exposures because of the sampling method. The 

personal air exposures from that HHE were among the lowest published for exposure to cocaine and 

are similar or greater than exposures we measured. In the same HHE, personal air exposures to 

methamphetamine ranged from not detected (minimum detection concentration = 0.003 μg/m3) to 

0.028 μg/m3 [NIOSH 2011]. These exposure concentrations were similar to those we measured. 

In one study of employees who manufactured fentanyl, full-shift TWA personal air exposures to 

fentanyl were 0.5–7,310 ng/m3 (0.0005–7.31 μg/m3), with a geometric mean of 40 ng/m3 (0.04 μg/m3) 

[Van Nimmen et al. 2006]. The majority of these pharmaceutical employee exposures were much higher 

than full-shift personal exposures we measured on chemists by several orders of magnitude. The 

geometric mean exposure we measured (0.007 μg/m3) was also much lower than the geometric mean in 

this study of pharmaceutical employees. None of the full-shift fentanyl exposures exceeded an 

occupational exposure limit established by a fentanyl manufacturing company of 0.1 μg/m3 [Van 

Nimmen et al. 2006].

In general, personal fentanyl and cocaine air exposures in this evaluation were much lower than those 

measured in similar studies or evaluations [Le et al. 1992; Gehlhausen et al. 2003; Van Nimmen et al. 

2006]. None of the interviewed employees reported any symptoms related to handling cocaine or 

opioids at work, and OSHA 300 Logs revealed only one employee with reported symptoms possibly 

associated with PCP. The potential health effects and symptoms from exposures to low levels of these 
B-15

drugs are not well characterized or understood. Table C5 details the health effects from higher levels of 

exposures to cocaine, fentanyl, heroin, and methamphetamine as found in scientific literature.

Air exposures to the four drugs measured on sampling days were low relative to those found in other 

studies and to one applicable occupational exposure limit. However, due to the unpredictable nature 

and origin of the evidence being handled, prudent occupational health practices call for minimizing the 

handling of evidence as much as possible, implementing engineering controls, and developing 

emergency response policies that would reduce the likelihood of exposure and subsequent health effects 

in the event of an acute spill or exposure. In this evaluation, employees who worked with evidence 

containing confirmed cocaine, fentanyl, and heroin had higher air exposures to the respective drugs they 

worked with than those who did not work with evidence containing those drugs and for cocaine, this 

difference was statistically significant. One assumption of Mann – Whitney U test is independence 

between the observations, in this case air measurements. When comparing air exposures of employees 

who worked with various drugs, versus those who did not work with those drugs, the impact of 

adjacent employees working with those same drugs is unknown. We assumed these air exposure 

measurements to be independent, with this assumption of independence being a limitation of this study.

Laboratory management can reference the practices of industries where employees work with 

biologically potent ingredients, like the pharmaceutical industry, as a model for exposure control. 

Surface Contamination and Handwipes

The surface sampling data showed that laboratory surfaces that were not cleaned as frequently as bench 

tops (keyboard covers and shelving) were contaminated with higher concentrations of drugs. We 

observed that cleaning practices varied by laboratory, and oftentimes depended on the chemist(s) using 

the workstation. Some chemists cleaned their benchtops and/or keyboards between every case using 

methanol, others less often, and still others relied on using a disposable barrier paper to prevent surface 

contamination. Laboratory benches were also among the surfaces that were most contaminated with 

drugs, with almost all wipe samples having reportable concentrations of cocaine, fentanyl, heroin, and 

methamphetamine.

We measured methamphetamine and cocaine concentrations that were much lower than the maximum 

concentrations found on police station surfaces. In one study, which measured amounts of drugs on 

surfaces in police stations, methamphetamine and cocaine were among the most frequently detected 

drugs on surfaces and were also the drugs found in the highest concentrations [Doran et al. 2017]. The 

heroin metabolite 6-monoacetylmorphine (6-MAM) was also found on surfaces in the police stations. 

That study found no correlation between the amount of drugs on surfaces and the number of drugbased arrests at the police station, concluding that the amount of drugs on surfaces is more influenced 

by factors like the amount of drug seized, the surface types at each police station, and cleaning practices 

[Doran et al. 2017]. 

In an HHE from 2011, surface concentrations of drugs in a police department drug vault were similar 

to surface concentrations we measured for methamphetamine (maximum 0.079 μg/100 cm2) and 

cocaine (maximum 7.3 μg/100 cm2) [NIOSH 2011]. 

All of the surface samples we collected at the three laboratories were below a fentanyl surface 

contamination limit developed internally by a fentanyl manufacturer (1 μg/100 cm2) [Van Nimmen and 
B-16

Veulemans 2004]. Two laboratory bench surfaces, two keyboards, and a shelf in the laboratory met or 

exceeded the surface remediation limit proposed by a county health department for fentanylcontaminated properties (0.1 μg/100 cm2) [Rosen 2018]. Dry sweeping and dry cleaning practices 

reported by some chemists and maintenance staff could potentially aerosolize these substances in the 

laboratories.

The EPA has published protocols for methamphetamine cleaning and decontamination focused on 

cleaning methamphetamine laboratories [EPA 2013]. Although the EPA has not established 

quantitative post-cleanup standards for methamphetamine and associated chemicals, many state and 

local agencies have done so. These post-cleanup standards for methamphetamine range from 0.05 to 

1.5 μg/100 cm2, with the most common standard being 0.1 μg/100 cm2 [EPA 2013]. Most of these 

remediation standards are based on analytical detection limits and feasibility and are not based on 

health. However, these standards are believed to be conservative enough to be protective of health and 

environment [Colorado Department of Public Health and Environment 2005]. Seven 

methamphetamine surface wipe samples in our evaluation exceeded the most common 

methamphetamine cleanup standard of 0.1 μg/100 cm2. One of these wipe samples, taken on the 

keyboard with removable cover, exceeded the highest cleanup standard. We did not identify any cleanup 

or occupational standards for heroin or cocaine on surfaces.

All the postshift handwipe samples collected had higher amounts of a given analyte compared to 

preshift handwipe samples, unless both samples did not have reportable levels (> 1 ng/wipe). Cocaine 

was present in 9 of 13 preshift handwipes, reflecting the relative pervasiveness of cocaine on surfaces 

and items that normally would not be in contact with illicit drugs. Preshift handwipes were mostly not 

reportable for fentanyl, heroin, and methamphetamine with a few exceptions. These exceptions could 

indicate contact with surfaces contaminated with these drugs at work but outside of the laboratory, 

contact with surfaces contaminated with these drugs prior to work, or drugs remaining on hands from 

the previous work shift. While hand hygiene was self-reported to be good by interviewed employees, 

quality hand hygiene should be encouraged for all laboratory employees.

Cleaning and Decontamination

Research is underway on the cleaning and decontamination of illicit drugs, particularly fentanyl. 

Fentanyl degrades when exposed to oxidant solutions [Qi et al. 2011]. Products that contain or generate 

peracetic acid may also be effective in the decontamination of fentanyl and carfentanil, but guidelines 

on amounts and durations have not been established [EPA 2018]. UV radiation and temperature may 

also be effective in degrading fentanyl [Reitstetter and Losser 2018]. The EPA Fact Sheet for On-Scene 

Coordinators on Fentanyl and Fentanyl Analogs describes strategies for decontamination and cleanup 

in various forms and on different surfaces [EPA 2018]. Cleaning and decontamination methods for 

fentanyl may be effective for heroin and other illicit opioids. The staff at the laboratories we visited used 

a methanol solution to clean laboratory surfaces. One study demonstrated several cleaning protocols 

that had greater than 97% removal efficiencies, including methanol, soap and water, OxiCleanTM, 

adhesive and methanol, and Dahlgren Decon solution [Sisco et al. 2019]. We found mention of 

methanol as a cleaning agent in remediation settings for some drugs [Owens et al. 2018]. 
B-17

Exposure Controls

Due to the impact of the opioid crisis, many federal agencies and professional organizations have 

provided guidelines on keeping workers safe from fentanyl, its analogues, and other opioids through 

engineering controls, work practice changes, and PPE. The American Academy of Forensic Science 

(AAFS) published a position statement recommending control methods that follow the hierarchy of 

controls approach when handling and analyzing suspected synthetic opioids. These controls include 

implementing strict evidence acceptance protocols; using engineering controls such as evidence 

packaging, fume hoods, and balance enclosures; and using work practices including good lab technique 

and housekeeping [AAFS 2017]. Additionally, the AAFS recommends implementing an emergency 

response plan that includes spill control, decontamination, first aid, naloxone use, and appropriate 

training on these safety protocols [AAFS 2017]. The American Society of Crime Laboratory Directors 

provides more specific recommendations that include changes to packaging/storage, updates on 

laboratory practices, use of alternative sampling devices (to test evidence without removing it from 

packaging), adopting a naloxone policy, as well as training and education [American Society of Crime 

Laboratory Directors 2018]. 

Ideally, all evidence should be handled and analyzed in a fume hood, and there should be one fume 

hood for each chemist. However, the current lab configurations and the number of fume hoods at each 

lab we evaluated does not allow this to occur. We did not observe fume hoods being used for casework. 

Further inspection of the fume hoods showed that none were certified to have acceptable face velocity. 

Some fume hoods had face velocities outside of the standard range, either below or above the 

recommended average face velocity of 100 fpm (range 80–120 fpm). Face velocities lower than 

recommendations may be inadequate to capture contaminants. Face velocities higher than 

recommendations may cause airflow turbulence, which reduces the ability of the fume hood to capture 

contaminants and may even cause contaminants to escape the hood. Higher than recommended airflow 

also results in higher electricity use and expenses while not improving capture efficiency. In this 

evaluation, the high face velocities we measured also make it difficult to work with or weigh powders 

inside the hood. Furthermore, when sampling powders and when balance sensitivity is important, a 

ventilation hood enclosure designed for this activity, such as a powder hood, should be used. 

In Laboratory A, LEV with an adjustable snorkel hood was available at each workstation, but was not 

used during our visit or otherwise routinely, according to staff. ASHRAE laboratory design guidance 

calls these “snorkel-type” moveable hoods appropriate for removing heat and no- or low-hazard 

airborne contaminants [ASHRAE 2015]. This type of LEV is not ideal in forensic drug laboratories 

because employees routinely handle hazardous materials. When asked, several chemists were unclear on 

the function and proper use of ventilation controls in protecting them from drugs in evidence. Useradjustable LEV is not routinely used in similar workplaces where biologically active materials are 

handled and sampled, like pharmaceutical manufacturing facilities. When employees can be exposed to 

high-hazard materials in air (like potent opioids and other powdered controlled substances), laboratory 

ventilation guidance and pharmaceutical industry resources prioritizes product containment and 

isolation through exposure control devices, such as variable air volume fume hoods, laminar flow 

ventilated hoods or cabinets, and ventilated gloved boxes [ASHRAE 2015, 2018; Wood 2010]. 
B-18

NIOSH does not have specific PPE guidance for chemists but does provide guidance on recommended 

PPE during investigations and evidence collection. Different levels of PPE are recommended 

depending on the amount of fentanyl present. At minimal exposure levels, defined by a response where 

suspected fentanyl may be present but none is visible, nitrile gloves are recommended. At moderate 

exposure levels, defined by a response where small amounts of fentanyl products are visible, a 

disposable 100-series filtering facepiece respirator (e.g., P100 filtering facepiece respirator), safety 

goggles/glasses, and wrist/arm protection are recommended in addition to nitrile gloves [NIOSH 

2017]. These two exposure levels are most similar to chemists’ exposures during the course of their 

work. Published guidance from the AAFS and The InterAgency Board provides similar PPE 

recommendations [AAFS 2017; The InterAgency Board 2017].

Because of the variability in incoming evidence, scenario-based protocols would be an effective 

approach to writing guidelines. This means that guidance on what engineering controls and PPE should 

be used for a specific type of evidence would be useful. Guidelines should include clear policies for how 

and where chemists can process evidence. For example, the testing of small amounts of evidence may 

be done on the desktop, but non-trace evidence or evidence from suspected traffickers should be 

sampled in a fume hood or other ventilated enclosure.

Respiratory protection guidelines and requirements in the respiratory protection program in our 

evaluation were not specific to forensic laboratory work but rather applied to all police department staff 

enrolled in the plan. These gaps left employees unsure when they were required to wear respiratory 

protection and when it was optional. When we spoke to employees, the determining factors varied and 

included the form of the evidence (powder or not) and/or the suspected identity of the substance. 

However, we observed that the suspected identity of the evidence frequently differed from the actual 

identity of the evidence. 

An additional type of respirator, the air-purifying elastomeric half-mask respirator, was provided to 

employees in the last several months before our visit. However, most employees did not wear this 

respirator, reporting to us that they did not know when or if it was required and that it caused 

headaches or pain when worn. Review of the health and safety documentation, including the respiratory 

protection program and communications with employees, did not appear to provide specific guidance 

about which activities require respirator use and how to select which respirator to use. NIOSH 

recommends respirators with P100 particle filtration for first responders with possible fentanyl 

exposures in air, which the air-purifying half-face elastomeric respirator provides in this workplace 

[NIOSH 2017]. In dedicated laboratory space, engineering controls, rather than frequent respiratory 

protection use, is the preferred method of exposure control. Respiratory protection should be limited to 

emergencies, such as spills, or nontypical sampling or processing that cannot occur within a ventilated 

workspace. 

Contracted facility environmental services employees wore N95 respirators when emptying trash 

containing discarded barrier papers and small amounts of evidence. Based on the respiratory protection 

program and conversations with management, it was unclear who was responsible for the respirator

protection program in which environmental staff should be enrolled. 
B-19

We observed all employees wearing nitrile gloves when they handled suspected illicit drug evidence. 

Therefore, the hand contamination we measured is likely from contacting bare hands with 

contaminated surfaces like laboratory benches, keyboards (and keyboard covers), door handles, sink 

handles, or from removing gloves in such a way that contaminates the hands. Some chemists typed on 

their workstation keyboard without removing contaminated gloves and then typed with bare hands, 

which could be a source of contamination. We observed most employees wearing safety glasses and 

laboratory coats while in the laboratory on the second site visit. However, interviewed employees’ selfreported use was variable.

Limitations 

This evaluation was subject to several limitations. First, industrial hygiene sampling can only document 

exposures on the day of sampling in the locations sampled. These results may not be representative of 

conditions during other days as the casework varies day to day. Second, because the interviews asked 

employees about past workplace processes, practices, and conditions; exposures; and health effects, 

these results are subject to recall bias.

Conclusions

Employees at three controlled substances laboratories reported no symptoms associated with acute 

exposure to cocaine, fentanyl, heroin, or methamphetamine. However, we identified the potential for 

unintentional exposures in the air and on contaminated surfaces and hands for all four drugs sampled. 

We provided recommendations to assist the laboratories in minimizing exposures to these substances. 

These recommendations included changing workplace practices that potentially increase exposure risks, 

creating a more effective respiratory protection program, and training employees on protocols to 

improve employee safety.
C-1

Section C: Tables

Table C1. Summary full-shift personal air sample concentrations (μg/m3)*

 Cocaine Fentanyl Heroin Methamphetamine

Geometric Mean 0.065 0.007 0.018 0.005

Max 0.72 0.04 0.31 0.03

Min NR NR NR NR

NR = concentration is below the minimum reportable concentration

* The minimum reportable concentrations range from 0.004 to 0.005 μg/m3. 

Table C2. Individual full-shift personal air sample concentrations (μg/m3) 

Participant Sample 

duration 

(minutes)

Cocaine Fentanyl Heroin Methamphetamine MRC

1 223 0.066 0.018 0.049 NR 0.005

2 396 0.021 0.030 0.15 0.028 0.005

3 441 NR NR 0.011 NR 0.005

4 460 0.006 NR 0.061 NR 0.004

5 400 0.005 0.041 0.31 0.012 0.004

6 415 0.20 NR 0.009 NR 0.005

7 408 0.72 0.028 0.044 NR 0.004

8 385 0.55 NR 0.006 NR 0.005

9 478 0.12 NR NR NR 0.004

10 428 0.099 NR NR NR 0.005

11 492 0.072 NR 0.012 0.005 0.005

12 424 0.65 NR NR NR 0.004

MRC = Minimum reportable concentration

NR = concentration is below the minimum reportable concentration
C-2

Table C3. Individual preshift and postshift handwipe samples (ng/swab)*

Participant Cocaine Fentanyl Heroin Methamphetamine

 Preshift Postshift Preshift Postshift Preshift Postshift Preshift Postshift 

1 16 830 NR 11 1.1 53 NR 7.5

2 2.3 25 NR 4.0 2.1 30 NR 32

3 NR 77 NR 2.7 NR 17 NR NR

4 1.4 93 NR 5.3 NR 66 NR 3.7

5 19 140 NR 8.9 3.5 160 5.7 33

6 NR 18 NR NR NR 1.0 NR NR

7 4.2 310 NR 11 NR 20 NR 5.2

8 8.8 2600 NR 5.0 NR 36 NR 100

9 NR 550 NR 3.0 NR 6.7 NR NR

10 1.5 100 NR NR NR 1.1 NR NR

11 1.1 120 NR NR NR 4.2 NR 4.2

12 1.1 350 NR NR NR 2.2 NR 1.1

13 NR 46 NR 5.9 3.0 17 NR 1.1

* Reporting limit was 1 ng/swab.
C-3

Table C4. Surface sample results (μg/100 cm2)*

Location Cocaine Fentanyl Heroin Methamphetamine

Keyboard cover 5.8 0.21 2.6 1.6

Keyboard under cover 0.49 0.0022 0.010 NR

Keyboard, no cover 4.0 0.021 0.68 0.046

Keyboard, no cover 1.7 0.13 0.078 0.0079

Keyboard, no cover 0.026 NR 0.0010 0.010

Laboratory bench surface 5.0 0.0012 0.0050 0.0084

Laboratory bench surface 4.2 0.37 0.16 0.13

Laboratory bench surface 2.9 0.023 0.046 0.035

Laboratory bench surface 1.9 0.0015 0.011 0.0018

Laboratory bench surface 1.8 0.0081 0.058 NR

Laboratory bench surface 1.8 0.054 0.11 0.060

Laboratory bench surface 1.4 0.052 0.032 0.25

Laboratory bench surface 1.0 0.037 0.083 0.048

Laboratory bench surface 0.81 0.10 0.048 0.17

Laboratory bench surface 0.78 0.060 0.11 0.0043

Laboratory bench surface 0.74 0.037 0.094 0.10

Laboratory bench surface 0.39 0.0068 0.0071 0.0017

Laboratory bench surface 0.075 0.078 0.23 0.45

Report desk NR NR NR NR

Report desk 0.044 NR 0.0029 0.0092

Report desk 0.014 NR NR NR

Shelf in laboratory 2.9 0.15 4.0 0.11

* The reporting limit was 1 ng (0.001 μg) per sample.
C-4

Table C5. Health effects of severe cocaine, fentanyl, heroin, and methamphetamine toxicity*

Controlled substance Health effects

Cocaine Dilated pupils, sweating, agitation, anxiety, elevated heart rate and blood 

pressure, heart arrhythmias, stroke, seizures, and high body temperature

Fentanyl Lethargy or other indications of central nervous system depression, shallow or 

slow breathing, miosis or pinpoint pupils, slow heart rate, low blood pressure, 

low body temperature

Heroin Lethargy or other indications of central nervous system depression, shallow or 

slow breathing, miosis or pinpoint pupils, slow heart rate, low blood pressure, 

low body temperature

Methamphetamine Dilated pupils, sweating, agitation, anxiety, hallucinations, elevated heart rate 

and blood pressure, heart arrhythmias, stroke, seizures, high body 

temperatures, and electrolyte abnormalities such as low potassium or sodium or 

elevated blood glucose

* [Bateman et al. 2014]

Table C6. Selected laboratory locations where interviewed employees reported working

Location No. of employees (n = 24)

Central receiving area 21

Controlled substances laboratory 20

Controlled substances laboratory instrument room 16

Report writing area 13
C-5

Table C7. Personal protective equipment reported to be worn by interviewed laboratory employees (n = 20)

Personal protective equipment No. forensic laboratory chemists 

(n = 13)

No. evidence inventory employees 

(n = 7)

Nitrile gloves 

Always 13 0 

Sometimes 0 6 

Never 0 1 

N95 respirator 

Always 3 0 

Sometimes 10 1 

Never 0 6 

Safety glasses/goggles 

Always 0 0 

Sometimes 4 1 

Never 9 6 

Table C8. Description of training received as reported by interviewed employees

Training No. of employees (n = 24)

What to do in the event of a sharps injury 18

Safely handling sharps 17

Safely handling evidence containing suspected cocaine/opioids 17

Recognizing signs or symptoms of opioid intoxication 16

Proper administration of naloxone 16
D-1

Section D: References 

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chromatographic-mass spectrometric screening method for the simultaneous determination of 

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narcotic analgesics in pharmaceutical production workers. Ann Occup Hyg 50(7):665–667, 

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Standards, Guidance, and Recommendations

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D-2

EPA [2013]. Voluntary guidelines for methamphetamine laboratory cleanup. Washington, DC: U.S. 

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D-3

Owens CV, Mason MM, Marr D [2018]. Remediation of manufactured methamphetamine in 

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opioids, including fentanyl and fentanyl analogues. Arlington, VA: The InterAgency Board, 

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PE%20and%20Decontamination%20Recommendations%20for%20Fentanyl.pdf. 
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