Policy Text
MOUNTAIN VIEW POLICE DEPARTMENT
SPECIAL SERVICES SECTION
TRAININ G AND INFORMATION
BULLETIN
PAGE 1 OF 2
CONFIDENTIAL • FOR LAW ENFORCEMENT USE ONLY
2020
DATE: August 12, 2020
BULLETIN NUMBER: 20-15
SUBJECT: Discontinued Use of Gaiter Masks
INFORMATION:
Effective immediately Gaiter style masks (bandanas included) are not to be used while
working your shift or c oming into the police department while off -duty . No exceptions.
This includes contact with the public, inside city buildings, and city vehicles.
Background:
A study by Duke University was published last Friday, August 7, 2020. The study took 14 differen t types of masks and measured particles emitted by people speaking while
wearing each of the masks. N-95 masks (no vent) were the most effective in blocking droplets. The study found that
double -layer masks, similar to the fa ce coverings supplied by Huma n Resources were
preferable to single layer coverings. Surgical masks were significantly better in reducing some droplet spread.
The study found that gaiter style masks were more likely to release a higher number of
respiratory droplets into the air than those who do not wear a face covering at all
because the material appears to break down larger droplets into aerosols.
The study was echoed by a new observational study by Australian researchers. The
study was also supported by an infectious disease doct or at Stanford University.
Approved Types of Protective Masks:
There are two types of protective masks : fabric masks and N95 masks (respirators).
Fabric Masks or face coverings are masks made out of fabri c or similar material. The
main difference between fabric masks and N95 masks is that the fabric mask does not
contain any medical filtering properties. In other words, the fabric mask only provides
MOUNTAIN VIEW POLICE DEPARTMENT
SPECIAL SERVICES SECTION
TRAININ G AND INFORMATION
BULLETIN
PAGE 2 OF 2
CONFIDENTIAL • FOR LAW ENFORCEMENT USE ONLY
2020
protection to those around the mask wearer by containing small particle aerosols within
the mask. The recommended mask should contain at least two layers of fabric.
For this reason , you should continue to follow the six foot social distan cing guideline
and wash your hands often. It is very important that the mask is worn tightly to
maximize protection.
N95 respirators reduce the wearer's exposure to airborne particles, from small particle
aerosols to large droplets. N95 respirators are tight -fitting respirators that filter out at
least 95% of particl es in the air, including large and small particles. These masks
provide two -way protection if they do not have a n exhalation valve . The wearer of
these masks is protected when making contact with the public. The public is also protected from the wearer s hould he or she have a virus, such as Covid -19.
Which one do I wear and when do I wear it?
Field Personnel - Sworn/CSOs/Police Assistants - When making public contact:
When personnel are in the field, N- 95 protective masks should be worn when makin g
contact with the public. N -95 mask s provide the best protection from any airborne
pathogens such as Covid -19. It is important that the mask is worn properly to
maximize protection .
When you are alone inside of your vehicle you may remove the mask. Handle these
masks with care and avoid touching the inside when donning and doffing the mask . It
is not recommended that you allow them to hang on your duty belt.
All Staff: When not making public contact and while working in the PD building ,
personnel sh ould wear a fabric or surgical mas k when i n shared or common areas.
** Fabric masks shall not contain any logos or symbols unless distributed by the
department . **
Prepared by: Force Protection Branch
Sgt. Fernando Maldonado
Approved by: Force Protection Branch
Lt. Dan Frohlich