and assembly should be facilitated by
the equipment design to optimize sani-
tary conditions.
- Elimination of product or liquid collec-
tion through self-draining equipment
that will ensure that debris, water, or
product liquid does not accumulate,
pool, or condense on the equipment or
product zone areas.
- Hollow areas of equipment (e.g.,frames
and rollers) must be eliminated if possi-
ble or permanently sealed. Bolts, studs,
mounting plates, brackets, nameplates,
junction boxes, end caps, sleeves, and
other such items must be continuously
welded to the surface of equipment
and not attached by grilled or packed
holes.
- All parts of the equipment must be free
of niches such as pits, cracks, corro-
sion, recesses, open seams, gaps, lap
seams, protruding ledges, inside threads,
bolt rivets, and dead ends. All welds must
be continuous and fully penetrating.
- During normal operations, the equip-
ment must perform so it does not con-
tribute to unsanitary conditions or the
harborage and growth of bacteria.
During processing, moisture and prod-
uct buildup should be minimal in dif-
ferent product zones. Modular plastic
belts with “Cam-link” or equivalent
hinges, which open wide around
sprockets to maximize cleaning access,
but stay closed on the conveyor bed to
prevent debris from clogging the belt,
merit consideration. Plastic should be
nonporous, and underside drive bars,
channel away water and debris.
- Maintenance enclosures (e.g., electrical
control panels, chain guards, belt
guards, gear enclosures, junction boxes,
pneumatic/hydraulic enclosures) and
human machine interfaces (e.g., push-
buttons, valve handles, switches,
touch screens) must be designed, con-
structed, and maintainable to ensure
that the product, water, or product liq-
uid does not penetrate into, or accumu-
late in or on the enclosure and
interface. Equipment with bearings and
gears that require lubricants should be
designed and constructed so that the
lubricant cannot leak, drip, or be
forced into food or onto food contact
surfaces. The physical design of the
enclosures should be sloped or pitched
to avoid use of the storage area.
- Design of equipment must ensure
hygienic compatibility with other equip-
ment and systems (e.g., electrical,
hydraulics, steam, air, water). The
hygienic compatibility to the equip-
ment with other systems is both a
processor and equipment manufacturer
responsibility.
- Procedures for cleaning and sanitizing
must be written clearly and validated.
Compounds recommended for clean-
ing and sanitizing must be compatible
with equipment and the manufacturing
environment.
According to Butts (2003), the food man-
ufacturer must either remove by design or
manage microbial growth niches as part of
the production and sanitation process for
ready-to-eat foods. Identified factors respon-
sible for growth niches include poor equip-
ment design, debris working its way into an
uncleanable location, mid-shift cleanup, and
existing product characteristics that cause
excessive rinsing such as producing sticky
products.
Ten sanitary design principles that are
adapted from those provided by Seward
(2004) are as follows:
Principle 1: Identify Distinct Hygienic
Zones Established in a Facility.A distinct
separation should be maintained to reduce
Sanitary Design and Construction for Food Processing 263
