A Review of Applicable OSHA Standards, Monitoring Strategies, and Potential Controls

1. Airborne Chemical
Exposure
A Review of Applicable OSHA
Standards, Monitoring Strategies,
and Potential Controls

2. 32 millions workers work with and are potentially exposed
to one or more chemical hazards.
OSHA Publication 3084
“Thousands of workers still are becoming ill and dying as
a result of exposure to hazardous chemicals.” –David
Michaels, Assistant Secretary of Labor, OSHA (2014)
OSHA has various standards to ensure workers are not
exposed to dangerous levels of hazardous chemicals at
the workplace.

3. Standards
• 1910.1000 Air Contaminants
– 3 tables listing substances by name and
corresponding exposure limits
• Z-1: Originally borrowed from 1968 ACGIH limits
• Z-2: Originally borrowed from existing 1970 ANSI limits
• Z-3: Mineral Dusts
• 1910.1001 to 1910.1052
– Specific chemical standards (we will review an
example)
• Related: 1910.134
– Respiratory protection

4. Time-Weighted Average
• TWA
– The average concentration of a contaminant
to which an employee is exposed over a
period of time.
– OSHA Permissible Exposure Limits (PELs)
are based on 8-hour work days
– Measured in ppm or mg/m3
DEFINITIONS

5. TWA Example Calculation
The PEL for methyl alcohol is 200ppm
An employee is exposed to:
– 350ppm between 8AM and 12PM
– 0ppm between 12PM and 2:30PM
– 85ppm between 2:30PM and 4PM
What is TWA?
(350*4 hours)+(0*2.5 hours)+(85*1.5 hours)
8 hours = ~191 ppm

6. Extended Work Shifts?
• OSHA only specifies 8-hour shifts in most
cases
• Brief and Scala Method is recommended:

7. Extended Work Shifts?
What if you work a double shift? It is not simply
half the value for twice the time working.
RF = (8/16) * (24-16/16) = 0.25
The PEL for methyl alcohol is 200ppm (8 hours)
The 16-hour PEL for methyl alcohol is the
RF*200ppm = 50ppm

8. Mixture of
Contaminants?
Em=(C1÷L1)+(C2÷L2)+…(Cn÷Ln)
Where:
Em is the equivalent exposure for the mixture.
C is the concentration of a particular contaminant.
L is the exposure limit for that substance specified in subpart Z of 29 CFR part 1910.
The value of Em shall not exceed unity (1).
Example Calc.

9. Ceiling Values
• Denoted with (C) in Table Z-1
• Employee exposures “shall at no time
exceed the exposure limit given for that
substance.”
• If you can’t measure instantaneously, the
ceiling shall be assessed as a 15-minute
TWA.

10. Short Term
Exposure Limit
• TWAs over 15-minute
periods (generally)
• Most are found in specific
chemical standards
Action Level
• Exposure concentrations
that trigger certain
regulations (specific
chemical standards)
DEFINITIONS

11. Exposure Assessment Programs
An effective exposure assessment program will:
1. Accurately characterize hazardous work
processes
2. Allow exposure data to be tracked over time
3. Demonstrate regulatory compliance
(documentation, analysis, schedule)
4. Prioritize controls used

12. Survey Protocol
Prior to conducting chemical sampling a survey protocol should be
developed. This protocol serves as a guide in performing the survey. The
amount of detail necessary will depend on the purpose of the survey and
to whom the results will be submitted. At a minimum, the protocol should
include the following:
1. Purpose of the survey. Why is the survey being conducted and what is the
desired outcome? Background information such as previous surveys,
operational or equipment changes should be referenced.
2. Where to sample. This identifies expected exposure sites. It is based on
where chemicals are stored, transported, and used at the site, and what
ventilation and airflow patterns exist.

13. Survey Protocol
Prior to conducting chemical sampling a survey protocol should be
developed. This protocol serves as a guide in performing the survey. The
amount of detail necessary will depend on the purpose of the survey and
to whom the results will be submitted. At a minimum, the protocol should
include the following:
3. What to sample. This is based on available information. What are the
potential chemical hazards?
4. Who to sample. This is based on knowledge of the potential exposure
sites and the various job requirements at the site. What job
classifications or specific individuals should be considered for
monitoring? Workers with the greatest potential for exposure must be
included.

14. Survey Protocol
Prior to conducting chemical sampling a survey protocol should be developed. This
protocol serves as a guide in performing the survey. The amount of detail necessary will
depend on the purpose of the survey and to whom the results will be submitted. At a
minimum, the protocol should include the following:
5. How many samples should be collected. Consider the number of exposure sites, job
classifications, and potential chemical hazards. How many samples are necessary
to assess the various exposure hazards?
6. How will the samples be collected and analyzed. After determining the potential
hazards, what published methods are available, and which ones will provide the
most meaningful data. Is there a potential for other chemical hazards in the area and
should methods be considered which may provide screening information?

15. Risk Assessments
• Are any of the substances listed used in
work operations?
– Look at work processes in all areas
– Retrieve information from Safety Data Sheets
• Are they listed only in the Z tables, or is
there a specific chemical standard?
This is the employer’s responsibility!

16. Monitoring
• Employee exposures must be determined
from breathing-zone air samples.
• Classify workers into SEGs (Similar
Exposure Groups)
– Similar work operations at similar frequencies.
– Grouped by work title or department, but not
necessarily
– Choose HIGHEST RISK operations at
HIGHEST RISK times (worst-case).

17. Monitoring Equipment
• Equipment needs vary greatly, depending
on the contaminant.
– In general, the contaminant is collected on a
filter over a known amount of time or air
volume.
– The filter is sent to a laboratory and the total
amount of contaminant is measured.
– The amount of contaminant is divided by the
total time or air volume.

18. • Contaminants such as solvents and
volatiles can often be collected with
passive monitors (e.g., charcoal or
dinitrophenylhydrazine)
Monitoring Equipment

19. • Other contaminants, such as dusts, metals, and
asbestos, are collected on glass fiber, mixed
cellulose ester, or PVC filters.
Monitoring Equipment

20. Monitoring Equipment
• Personal Sampling Pumps –must be
calibrated accurately

21. • OSHA has an index of validated sampling and
analytical methods.
• It is best to consult with an industrial hygienist or
directly with the analytical laboratory to determine the
best sampling method.
Monitoring Equipment

22. Review of 1910.1025 - Lead
Scope
• Does not apply to construction
industry or agricultural operations
(covered by other standards)
• Action Level defined as 30 ug/m3
for 8-hour TWA
• Includes metallic lead, inorganic
lead compounds, and organic lead
soaps—does not include all other
organic lead compounds

23. PEL
• 8-hour TWA = 50 ug/m3
• For shifts greater than 8 hours, use the
following formula:
– PEL = 400/hours worked in day
Review of
1910.1025 - Lead

24. Initial Determination Lead Exposure
• Considerations:
– Info, observations, or calculations that indicate employee exposure to
lead
– Previous airborne measurements
– Employees report symptoms attributable to lead
• Initially, monitoring may be limited to a “representative sample
of the exposed employees who the employer reasonably
believes are exposed to the greatest airborne concentrations
of lead in the workplace.” (can be up to 12 months old)
Review of
1910.1025 - Lead

25. Review of
1910.1025 - Lead
Results are below the Action Level?
• Employer must create a written record of
determination.
• Must include considerations from previous slide
• Must include date, location within the worksite,
and the name and SS# of each employee
monitored.

26. Results are above the Action Level but below
PEL?
• Monitoring must be repeated every 6 months
until…
• Two consecutive measurements, taken at least 7
days apart, are below the Action Level.
• …then can be discontinued.
Review of
1910.1025 - Lead

27. Review of
1910.1025 - Lead
Results are above the PEL?
• Monitoring must be repeated every 3 months
until…
• Two consecutive measurements, taken at least 7
days apart, are below the PEL.
• …then monitoring must continue every 6 months
(previous slide).

28. Review of
1910.1025 - Lead
Additional Monitoring
• If there is any production, process, control, or personnel
change that may result in new or additional lead
exposures, then monitoring must be conducted.
Notification and Written Compliance Program
• Employees must be notified of any monitoring results
within 15 days of receipt of results.
• A written compliance program must be developed

29. Limitations of PELs
• “OSHA recognizes that many of its permissible
exposure limits (PELs) are outdated and
inadequate for ensuring protection of worker
health.”
– Adopted in 1970, from available consensus standards
at the time
– Almost 50 years of industrial experience, new
developments in technology, and scientific data since
then

30. NIOSH Recommended
Exposure Limits
• National Institute of Occupational Safety and
Health
– Under the Center for Disease Control
– Legislative mandate to recommend legally
enforceable standards to OSHA
– Evaluate all medical, biological, engineering,
chemical, and trade information

31. ACGIH Threshold Limit Values
• American Conference of Governmental
Industrial Hygienists
– Private, non-profit organization
– Health-based, not intended to be used as
legal standards
– “Gold standard”

32. OSHA vs. NIOSH vs. ACGIH
Formaldehyde
OSHA
8-hour TWA 0.75 ppm
STEL 2 ppm
NIOSH
TWA 0.016 ppm (Ca)
Ceiling 0.1 ppm [15-minute]
ACGIH
Ceiling 0.3 ppm (URT, eye irr.)

33. Interpreting Results

34. Sample
• ppm = 180
• ug = 8200
• time = 392 minutes (6 hours 32 minutes)
• OSHA PEL for Xylene: 100ppm
-Is this an overexposure?
(Best case: ~146 ppm 8-hour TWA)
(180*6.5 + 0*1.5)/8)
Interpreting Results

35. Xylene Case Study - Next Steps?
• Employee interviews – tissue fixing in histology
department at a healthcare facility
– Was the work routine?
– Did anything happen out of the ordinary?
– How often do you perform this work?
– Are there other employees in your department that
also do this?

36. Controlling Employee Exposure

37. Xylene Case Study –
Mitigating Hazards
• Elimination/Substitution
– Get rid of hazardous chemical in the first place
– Xylene substitute option: HistoClear Clearing
Agent
(from safety data sheet)

38. • Engineering Controls
– Work was performed in a fume hood
– Can additional operations be performed under the hood? Does
this require changing the size of containers or other equipment?
– Is the fume hood functioning properly?
– Can general dilution ventilation be increased in the room?
Xylene Case Study –
Mitigating Hazards

39. Xylene Case Study –
Mitigating Hazards
• Administrative/Work Practice Controls
– Fume hood sash height O.K.?
– Re-training in proper chemical handling?
– Split shifts with another employee? I.e., if this
work is performed 6 hours a day, potentially
have 2 employees performing the work for 3
hours a day each.

40. Xylene Case Study –
Mitigating Hazards
• Personal Protective Equipment
– Air-purifying respirator is the last option
– All respiratory protection must comply with
1910.134, which includes medical clearance,
annual fit-testing, training, and equipment supply.
– APRs usually have an assigned protection factor
of 10
• If exposure is 180ppm with no respiratory protection,
then it can be estimated to be 18ppm with a respirator
with an APF of 10.

41. Controls
• The controls used to reduce lead exposure
are laid out in detail in this standard:
– Mechanical ventilation testing must occur every 3
months
– If air is recirculated, a high efficiency filter must
be used
– Job rotation schedule must include employee
names, durations, and exposure levels
– Respirator use
Review of
1910.1025 - Lead

42. Controls
• The controls used to reduce lead exposure
are laid out in detail in this standard:
– Employers must provide clean protective clothing
daily or weekly; launderer must be notified in
writing and laundry must be labeled appropriately.
– Specific regulations on housekeeping, showering,
lunchrooms, lavatories, etc.
– Medical surveillance program must be instituted
for all employees exposed above the Action Level
for more than 30 days a year.
• Included blood sampling
Review of
1910.1025 - Lead

43. Do you have an exposure
monitoring plan?
QUESTIONS?

44. THANK YOU!
Mike Maffuccio, CIH
Environmental Compliance Consultant
Triumvirate Environmental
mmaffuccio@triumvirate.com
646-256-7396