1. Formaldehyde Exposure Measurement at Capital Health

2. Formaldehyde - Introduction
Formaldehyde uses at Capital Health:
Pathology
Morgue
Tissue preservation

3. Formaldehyde - Introduction
Tissue Preservation
10% buffered neutral formalin
Volumes used 20 ml to 20 L

4. Formaldehyde-Introduction
Tissue Preservation - Pathology

5. Formaldehyde Exposure Limits
Alberta Occupational Health and Safety Code
8-hour TWA OEL ppm
Protect against carcinogenicity
Ceiling limit – 2 ppm
Protect against irritation of eyes, nose and upper respiratory tract

6. Formaldehyde Exposure Limits
College of American Pathologists and College of Physicians and Surgeons of Alberta Accreditation Requirements:
8-hour TWA exposure limit ppm
8-hour TWA action level – 0.5 ppm
15 min STEL – 2 ppm
Must be maintained below these levels in areas of Anatomic Pathology
After initial monitoring, further monitoring is mandated if results equal or exceed 0.5 ppm ( action level) or 2 ppm STEL

7. Formaldehyde Exposure Limits
College of American Pathologists and College of Physicians and Surgeons – Cont’d
Initial monitoring must be repeated anytime change in production, equipment, process, personnel, or control measures which may result in new or additional exposure to formaldehyde.
Periodic monitoring is mandated only if the initial monitoring is at or exceeds 0.75 ppm (8 hour TWA) or 2 ppm ( STEL).
If any personnel report signs or symptoms of respiratory or dermal conditions associated with formaldehyde exposure, the laboratory must promptly monitor the affected person’s exposure
Requires that monitoring be performed in accordance with Alberta Occupational Health & Safety Act, code and Regulations.

8. Formaldehyde Exposure Limits
Alberta Occupational Health and Safety Code , Part 4 Chemical Hazards, Biological Hazards and Harmful Substances 20(1):
‘If a person measures the airborne concentration of a harmful substance for the purposes of complying with the occupational exposure limits as required by the Code, the person must make the measurement
(a) in accordance with the NIOSH Manual of Analytical Methods, 4th Edition (August 1994), …. including the 2nd supplement (January 15, 1998), or
(b) using methods or procedures that are approved by the Director of Occupational Hygiene….”

9. Formaldehyde- Potential Exposure Incidents
What Kind of Sampling / Measurement is Needed?
TWA( 8 hour )
Short term (STEL)
Ceiling limit

10. Formaldehyde- Potential Exposure Incidents

11. Formaldehyde- Potential Exposure Incidents

12. Formaldehyde- Potential Exposure Incidents

13. Formaldehyde- Potential Exposure Incidents

14. Formaldehyde- Measurement
What measurement method is needed to measure Ceiling Limit exposures?
What is available?

15. Formaldehyde Exposure Limits
Alberta Occupational Health and Safety Code , Part 4 Chemical Hazards, Biological Hazards and Harmful Substances 20(1):
‘If a person measures the airborne concentration of a harmful substance for the purposes of complying with the occupational exposure limits as required by the Code, the person must make the measurement
(a) in accordance with the NIOSH Manual of Analytical Methods, 4th Edition (August 1994), …. including the 2nd supplement (January 15, 1998), or
(b) using methods or procedures that are approved by the Director of Occupational Hygiene….”

16. Formaldehyde- NIOSH Methods
Description
Max. Flow rate (L/min.)
Min Volume (L)
Min Time
Detection Limit
Minimum Concentration
2016
DNPH treated silica gel tubes- HPLC
1.5 1
40 sec
0.23 ug
0.2 ppm
2541
HMP treated XAD-2 tubes-GC
0.1
10 min
3 ug
2.7 ppm
3500
Impinger, bisulfite- colorimetric
1.0
1 min
2 ug
1.8 ppm
3800
Extractive FTIR- direct reading NA
1 min to fill gas cell (Miran SapphIRe)
0.4 ppm (10 meter gascell)
0.4 ppm

17. Formaldehyde- Measurement
No evaluated NIOSH methods were found suitable for Ceiling Limit formaldehyde measurement.
Direct reading instrument must be used

18. Formaldehyde- Measurement
Requirements of Direct Reading Instruments:
Instrument method must be sensitive to 0.05 ppm
Instrument must be accurate (±25% of true reading 95% of time- NIOSH/OSHA criteria)
Instrument method must be able to take readings in as close to real time as possible (~ 10 second response time or less)
Instrument method must be free of other interferences (formalin contains a high proportion of methanol, health care has many other background VOC’s)

19. Formaldehyde- Measurement
Requirements of Direct Reading Instrument – Cont’d:
Data logging capability so that Ceiling Limit exceedances can be captured, then correlated to work log
Method must be approved by Director of Occupational Hygiene- Alberta Occupational Health and Safety

20. Formaldehyde- Measurement
Direct Reading Instruments Available:
Formaldemeter - poor response and interference from methanol and other oxidizable VOCs.
CEA Instruments - very sensitive, too slow response to give real time, potential interferences.
Miran sapphIRe - 1 minute cell fill time, not real time instrument, limited sensitivity, interferences.
Detector tubes (Dragar, Gastec)- too slow response to give real time, poor sensitivity

21. Formaldehyde- Interscan

22. Formaldehyde- Measurement
Literature Review References for Interscan Instrument:
Liu,F et al reported no statistical difference between Interscan and a phenol reagent method (J. Env. Health., Vol 20, No.2, 2003.)
NCASI Technical Bulletin 579 Laboratory and Field Evaluation of a Portable Continuous Analyzer for Measurement of Formaldehyde in Workplace Atmospheres
ppm - mean difference was 3.5%, coeff. var

23. Formaldehyde- Measurement
Literature Review References for Interscan Instrument Cont’d:
NIOSH procedure RCT-APR-STP-0039, Determination of Formaldehyde Service Test Life, Air Purifying Respirators Standard Testing Procedure
Mentions Interscan to give “real” time numbers in order to determine when formaldehyde breakthrough occurs in air purifying cartridges.

24. Formaldehyde- Measurement
Literature Review References for Interscan Instrument Cont’d:
US EPA Final Report IE 2814 Residential Indoor Air Formaldehyde Testing Program: Pilot Study
Used Interscan for real time formaldehyde measurements in conjunction with integrated sampling methods for building material off-gassing testing.
US EPA Method 21 Determination of Volatile Organic Compound Leaks
Gives specifications and performance criteria of direct reading instruments used in leak detection.

25. Formaldehyde- Interscan
Method of function
Electro-chemical voltametric sensor
Electro-catalytic sensing electrode
Sample pumped into instrument , then diffuses across medium to electrode
Sensor electrolyte immobilized similar to electrolyte in alkaline batteries
No problem with leakage, orientation of sensor, sensor noise
Sealed reservoir eliminates reference electrode contamination
Very linear response allows single point calibration over wide range

26. Formaldehyde- Interscan
Sensitivity
-0.1 ppm
Accuracy
ppm- mean difference was 3.5%, coeff. var
Real Time Response?
Almost immediate, <5 seconds
Interferences?
Minimal to other VOC’s and alcohols, instrument drift reported

27. Formaldehyde- Interscan
Data Logging Capability?
Yes - with external data logger (ACR Systems SmartReader7)
Approved by Director of Industrial Hygiene? No
Request to Alberta Human Resources and Employment for approval of Interscan 4000 series for formaldehyde- Sep/06
Dec / 06 approval granted with conditions:

28. Formaldehyde Interscan Approval
Conditions:
Specific to Capital Health facilities
Normal calibration is done at least quarterly when performing according to specifications within 35-65% RH.
Recalibration required on regular basis when RH outside %
Regular replacement of sensor due to reports of drift (manufacturer recommends quarterly or calibration check).

29. Formaldehyde- Interscan Test Trial
Calibration performed at ALS Laboratories.
1 m3 stainless steel calibration chamber
Paraformaldehyde powder diluted with inert silica powder, preweighed amounts heated to vaporize formaldehyde in chamber.
Formaldehyde concentrations measured by variety of methods.

30. Formaldehyde- Interscan Test Trial
Formaldehyde concentrations measured by variety of methods:
NIOSH DNPH treated silica gel tube--HPLC analysis
NIOSH Impinger/bisulfite-chromotropic acid- colorimetry.
Interscan 4000
Miran SapphIRe

31. Formaldehyde-Interscan Test Trial

32. Formaldehyde- Survey Results
Location- Anatomical Pathology Lab- specimen preparation/ grossing.
Workers- 2 histology technicians, one pathology assistant
Samples collected-
Six 8 hour TWA samples on each worker –
NIOSH DNPH treated silica gel/ HPLC analysis
Random / as-needed Ceiling Limit samples using Interscan 4000

33. Formaldehyde- Survey Results
TWA Sample Results
Description
Sample Time (min.)
Air Concentration (ppm)
Pathology Assistant
367
0.051
Histology Technician
456
0.11
414
0.030
Area- specimen receiving
473 / 474
0.017 / 0.02
Area- grossing
471
0.02
Area- specimen storage

34. Formaldehyde- Survey Results- GROSSING
Ceiling / Activity Specific Instantaneous Interscan Readings
Description
Ventilation Type
Air Concentration (ppm)
Grossing very large specimen
Local hood
0.050, 0.070, 0.070
Placing large specimen back into storage bucket
0.100
Grossing smaller specimen
0.065
Returning specimen to container on floor
General ventilation
0.080
Removing fixed specimen from container
0.04

35. Formaldehyde- Survey Results- GROSSING
Ceiling / Activity Specific Instantaneous Interscan Readings
Description
Ventilation Type
Air Concentration (ppm)
Grossing medium sample
Local hood
0.045, 0.050, 0.060, 0.050,
Returning medium sample to container-some splashing
0.120
Grossing smaller specimen
0.040, 0.045
Dumpling formalin into waste container
General ventilation
0.065
Removing fixed specimen from container
0.055

36. Formaldehyde- Survey Results- GROSSING
Ceiling / Activity Specific Instantaneous Interscan Readings
Description
Ventilation Type
Air Concentration (ppm)
Removing medium sample from container
Local hood
0.065
Grossing medium specimen
0.060
Opening specimen transport box- some formalin spillage
General only
1.60
Removing endoscopy samples from plastic bags
0.40, 0.65
Over garbage can (above plastic bags disposed of here)
1.10, 0.45

37. Formaldehyde- Results- AUTOPSY SUITE
Ceiling / Activity Specific Instantaneous Interscan Readings
Description
Ventilation Type
Air Concentration (ppm)
Specimen disposal
General only
0.80, 1.60, >1.99
Over open bucket of discarded used specimens
1.10
Room background- middle of autopsy suite, door closed
0.25
Addition of formaldehyde neutralizer and stirring to neutralize waste
0.45

38. Formaldehyde- Results- AUTOPSY SUITE
Ceiling / Activity Specific Instantaneous Interscan Readings
Description
Ventilation Type
Air Concentration (ppm)
Over open bucket of waste formalin
General only
<1.99
Over open bucket of ‘deformalized’ formalin
0.90
In specimen storage room-door open
0.20
In specimen storage room-after door closed 1 minute
0.45

39. Formaldehyde- Interscan
Discussion:
Interscan gave reliable, real-time information for formaldehyde concentrations
TWA average samples indicated that average concentration was well below OEL’s
However, Interscan identified activities/ tasks that exceeded or had potential to exceed Ceiling Limit OEL-
very variable readings
most likely log normally distributed with high standard deviation- highly skewed istribution

40. Formaldehyde- Interscan
Discussion Cont’d:
Added benefit:
worker is shown in real time the consequences of performing certain activities,
can make practice improvements
can immediately reassess changes in exposures from performing improved procedures
this is important in reducing exposures through education on chemical handling with Ceiling Limit OELs.

41. Acknowledgements
Craig Hrynchuk - Senior Manager, Regional Occupational Health, Safety and Wellness, Capital Health Authority
Chris Sheppard – Safety & Hygiene Consultant (formerly of Capital Health)
Doug Linman - Safety & Hygiene Consultant

42. Formaldehyde- Interscan
Questions?