ASHRAE Journal - September 2022 - 26

TECHNICAL FEATURE
TABLE 4 Actual particle intake of the chef in each restaurant (average per hour).
Maximum hourly intake allowed assuming 24/7 exposure to 25 µg/m³ is 270 µg.
ACTUAL
NR.
#1
CUISINE
University Restaurant
#2 Lunchroom (Eggs, Soup,
Sandwiches)
#3 Italian (Pasta, Fish, Meat)
#4 Dutch (Meat, Salads, Frying,
Oven)
#5
#6
#7
Irish (Hamburgers)
Asian (Wok)
Pancakes
PARTICLE
INTAKE
(µg/h)
71
68
143
26
102
-
181
% OF INTAKE,
P75 - P100
91%
68%
79%
74%
42%
-
70%
% OF INTAKE,
P95 - P100
71%
27%
50%
30%
12%
-
35%
Conclusions and Future Work
The outcomes from our laboratory study show that
the hood performance can have significant impact on
the PM2.5 concentration at breathing level. The indoor
air quality in the kitchen is compromised and the PM2.5
level in the breathing zone increases when hood exhaust
airflow is reduced below C&C level. It is also shown
that the hood design affects the C&C airflow required
to achieve the desired IAQ. The backshelf hood (test B1)
requires 70% less airflow compared to the canopy hood
(test C1) to achieve the same or a better IAQ. Finally, the
hood effectiveness improvement measures such as the
air curtain that were tested in this study significantly
reduced the PM2.5 level in the chef's breathing zone.
The outcomes from the (preliminary) field study show
that there is a high risk that chefs in professional restaurants
are exposed to PM2.5 concentrations well above the
WHO limits on a daily basis. These peaks were mostly
observed at identified cooking activities and when the
chef's head was below the hood. There is an effect of
the cooking style, characteristics of the restaurant and
ventilation system on the exposure level, but the results
presented in this study were too limited to be conclusive
on these issues. Reduction in the peak exposure for the
chefs is imperative.
A simple solution refers to the behavior of the chef.
However, this may be difficult to achieve in practice.
In addition, the exhaust hood performance may be
improved as well. Results from the lab study show that
such improvements can be achieved with the new developments
that come available (e.g., backshelf), though
it will not yet take out the peaks completely. Instant
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S E PTEM B E R 2022
feedback to the chef, additionally, may support effective
use of the hood and improved behavior of the chef.
The outcomes of the current study may contribute to
create more awareness of the exposure problem in kitchens
and support a change in the design and/or operation
of the kitchens. The behavior change will likely enable a
healthier working situation in addition to the technical
measures possible. Since the composition of the particulate
matter and the pattern of the exposure (e.g., high
exposure peaks) differ from general outdoor sources,
specific limits for exposure to PM2.5 in kitchens need to
be developed to incorporate these health impacts.
Further research could focus on measuring additional
pollutants in the kitchen environment, better defining
the characteristics of the ventilation system and cooking
styles as mentioned above, as well as setting standards
for adequate thresholds to reduce the exposure. As discussed,
behavioral change, in regard to both the position
of the chef and the selection of the type of exhaust
system, in addition to the technical measures (such as
optimizing the design of exhaust and stove combination)
may be required to enable a healthier working situation.
Acknowledgments
The project is financially supported by Halton B.V.
and the TVVL (the Dutch HVAC association). All restaurant
owners are thanked for their participation. Jesper
Priester is acknowledged for his assistance with the
measurements.
References
1. Kuehn, T., W. Gersler, D. Pui, J. Ramsey, M. Doerr. 1996.
" Identification and Characterization of Cooking Effluents As
Related to Optimum Design of Kitchen Ventilation Systems. "
ASHRAE Research Project RP-745, Final Report.
2. Kuehn, T., B. Olson, J. Ramsey, J. Rocklage, D. Gross.
2008. " Characterization of Effluents from Additional Cooking
Appliances. " ASHRAE Research Project RP-1375, Final Report.
3. Zheng, J., K. Han, B. Guo, Y. Zhang, C. Wu. 2016. " Countertop
Commercial Appliance Emissions, " ASHRAE Research Project RP1631,
Final Report.
4. Stoops, J., A. Watkins, E. Smyth, M. Adams, et al. 2013.
" Thermal Comfort in Commercial Kitchens. " ASHRAE Research
Project RP-1469, Final Report.
5. Feng, S., D. Gao, F. Liao, F. Zhou, X. Wang. 2016. " The health
effects of ambient PM2.5 and potential mechanisms. " Ecotoxicology
and Environmental Safety 128:67 -74.
6. Jacobs, P., W.A. Borsboom, R.E.J. Kemp. 2016. " PM2.5 in Dutch
dwellings due to cooking. " IAQ 2016. ASHRAE and AIVC Conference.
7. Shirin Hima Bindu, E., V.R. Mahalakshmi. 2016. " Indoor air
quality in commercial kitchens. " International Journal of Science and
Research 5(10):1337 -40.
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