- The document discusses exposure characterization methods used at 15 research laboratories with over 400 researchers using more than 1000 chemicals. Challenges included the large number and varying properties of chemicals used, variable usage quantities, and changing experiments. - Qualitative (QLEA) and quantitative (QNEA) exposure assessments were conducted. QLEA identified priority chemicals and activities, while QNEA involved air monitoring. Findings showed some priority exposures below limits while office areas had no detections. Recommendations included substituting chemicals, reducing inventory, modifying HVAC, and improving safety programs.

1. -Lili Deng
-International Safety Systems, Inc. Shanghai China
-T. Mehta, M. Mehta,
-International Safety Systems, Inc., Washingtonville, NY.
www.issehs.com

2. Agenda
Laboratories background
Challenges faced in Laboratories
Exposure characterization methods
Most common findings and recommendations

3. Laboratory Background
15 research laboratories exist
About 400 researchers work on site
More than 1000 chemicals were used
More than 100 research activities carried out
every year
Laboratories located in the same building as
offices

4. Which Challenges
We Faced to
Characterize
Employee Exposure

5. Ⅰ: Large number of chemicals used
More than 1000 chemicals with varying degree of
toxicity, physical and chemical properties used
Chemical Name ACGIH China
TLV-TWA PC-TWA
Methanol 200 ppm 25 mg/m3 ( 19.08 ppm)
n-Hexane 50 ppm 100 mg/m3 (28.37 ppm)
Acetone 500 ppm 300 mg/m3 ( 126.36 ppm )

6. Ⅱ: Variable quantity used
The chemical volume used varied significantly from
less than 5 ml to more than 300 ml/day
Chemical Name Quantity for every experiment
Methanol HPLC – about 300 ml
n-Hexane Diluting Sample – 5 ml
Acetone Glassware cleaning – about 50 ml

7. Ⅲ: Ever-changing experiments
High pressure and temperature experiments carried out in
one lab
In another lab different cleaning agents are used based on
the glassware contamination
Experiments Chemicals needed
Cleaning solution preperation Ethanol, Sodium hydroxide
Solvent distillation Acetonitrile, Petroleum ether, THF
Pressure reaction Methanol

8. Ⅳ. Others
Lab researchers have variable exposure duration
- They may stay in lab for 8 hours or 15 minutes
Lab researchers have limited safety background
- Most of the researchers have not been trained on safety before
they came at this research facility
office employees are located in the same building
where laboratories are located
- Dedicated ventilation system for lab and office area

9. Exposure Characterization Methods
• Qualitative exposure assessment
1st (QLEA)
• Quantitative exposure assessment
2nd (QNEA)
• Recommendations
3rd

10. Qualitative exposure assessment (QLEA)
QLEA was conducted at 15 research laboratory on site.
QLEA was conducted using a company developed model that
considered
chemical hazards
Frequency/duration of chemical used
Airborne potential
exposure control provided
Skin absorption
Ingestion potential.
Risk factors were ranked
Multiplication and addition of risk factors was done
Final Risk Ranking was computed

11. QLEA Criteria(Partial)
Rank 1 2 3 4 5
No. of persons 1–5 6 – 10 11 – 20 21 – 30 -
exposed
About ¾
Any / Minimal About ¼ Shift About ½ Shift Shift (5 to 7 (over 7
Daily Duration (under 1 hour) (1 to 3 hours) (3 to 5 hours) hours) hours)
OEL in OEL in OEL in OEL
range 3.1 to range 0.51 range 0.01 <0.01
Health Hazard 10 mg/m3 to 3 mg/m3 to 0.5 mg/m3
or >1000 or 101 to mg/m3 or 10 or <10 -
ppm 1000 ppm to 100 ppm ppm
Rank 0 1 2 3
Airborne Potential None Low Medium High -

12. Final Risk Rating Criteria
Total Final
Description Risk
Score Rating
Acceptable – process is well controlled and personal exposures are
<50 obviously unlikely to become significant 1
Potentially acceptable but it may be possible to further reduce
50-200 exposures by adopting simple recommendation.
2
Further evaluation needed – the qualitative assessment has not
200 - 400 provided enough information to be confident that personal 3
Not acceptable- Implement exposure controls, notify higher level
> 400 hygienist 4

13. Quantitative exposure assessment (QNEA)
Conducted for activities with Final Risk Rating of 3 and 4
QNEA was conducted for about 20 priority chemicals in 15
operations/activities prioritized based on QLEA
Area air monitoring conducted in office area to identify if
infiltration of chemicals are occurring into lab area
About 450 employee exposure samples were collected over
a period of 4 years
CIH conducted QLEA
EHS Specialist from China conducted exposure monitoring

14. Findings
Examples of operations with Final Risk Rating of more
than 200
Solvent purification
HPLC
Exposure monitoring conducted in these activities
identified exposure below China and ACGIH OELs
All area samples in office area identified
concentrations of contaminants below detection limit

15. Implemented Recommendations
Cleaning with methanol replaced with water based
cleaning agents
Chemical inventory reduced significantly
The laboratory HVAC system was modified to prevent
re-circulation of air in the laboratory
Respiratory protection program and personal
protective programs were modified
Safety Trainings were provided before employees
entering into laboratories and repeated at least once
every year