Chemical Engineering August 2022 - 44
Standard
TABLE 1. A SUMMARY OF SELECTED INDUSTRIAL SAFETY STANDARDS
Title/reference
Date of
issue
ISO 13849-1
ISO 13849-2
ANSI B11.0
ANSI/ISO
12100
OSHA 29, CFR
§1910.212
OSHA 29, CFR
§1910.147
ANSI/ASSE
Z244.1
OSHA 29, CFR
§1910.212
NFPA 79
NFPA 70E
ANSI B11.19
2015
2012
2020
2012
Not applicable
Not
applicable
2016
Not
applicable
2018
2021
2019
2015
Safety of machinery -
Safety-related parts of control
systems - Part 1: General principles
for design
2012 Safety of machinery -
Safety-related parts of control
systems - Part 2: Validation
2020 Safety of machinery -
General requirements and risk
assessment
2012 Safety of machinery - General
principles for design - Risk
assessment and risk reduction
General requirements for all
machines
Control of hazardous energy -
lockout/tagout (LOTO)
2016 Control of hazardous energy
- lockout/tagout and alternative
measures
Mechanical power-transmission
apparatus
2018 Electrical Standard for Industrial
Machinery
2021 Standard for electrical
safety in the workplace
2019 Performance Requirements
for Risk Reduction Measures:
Safeguarding and other
Market availability of differentiated
solutions and services from thirdparty
providers affords plants several
advantages. This enables plants
to use numerous products that may
not be rated for Class 1, Div. 2, but
still meet that certification by using
multiple relevant products (Figure 3).
3. Execute machine safeguards
As part of the manufacturer's machine
safeguarding solution, the
risk-mitigation strategy from the
risk assessment (Step 1) and functional
safety design of the controls
from the safety concept (Step 2)
are integrated into the existing
equipment to provide that final safe
working environment for the plant.
Typical safety-critical applications
within the chemical industry include
screen pack changers, box
dumpers, pelletizers, drum lines,
shrink wrappers and more. This
global chemical manufacturer has
all of these types of machinery and
plans are in place to apply appropriate
safety measures to each of
44
Typical application
Functional safety standard that
provides guidance on Performance
Levels
Functional safety standard that
provides guidance on validation
processes
Risk-assessment standard that gives
guidance on the process and what
hazards to look for
E.U. risk-assessment standard, which
is harmonized with ANSI B11.0
Provides guidance on machineryguarding
requirements
Guidance on LOTO on general machinery
More
recent guidance and current
state of the art on controlling hazardous
energy
Covers machinery-guarding requirements
for power-transmission equipment
Guidance
on emergency-stop buttons
(e-stops), color-coding for pushbuttons,
wires, fuses and so on
Arc-flash safety guidance
Guidance on applying safety devices,
guards, resets and so on
them. More details about specific
safety measures for each equipment
category are provided in the
following sections.
Screen pack changers. The chemical
manufacturer utilized screen
pack changers as a part of its process.
This machine's main purpose
is to remove contaminants from a
molten polymer stream. The screen
changer consists of a hydraulic cylinder.
The cylinder has two sections
in the slide plate where the molten
polymer flows through. The screen
packs on the machine can often be
changed during operation without
interrupting workflow or reducing
production time.
However, there are hazards associated
with this machine that
needed to be addressed. First,
there is the potential for third-degree
burns from the molten hot
polymer that flows through the machine.
Second, it provides a pinchpoint
hazard with the potential for
amputation of limbs. Both of these
safety hazards were addressed as
part of the risk mitigation strategy,
and the machinery was made safe
to meet standards and ensure the
safety of workers interacting with
this machinery with Class 1, Div. 2
non-contact safety switches and
other safety equipment.
Shrink/stretch wrapper. The
shrink/stretch wrapper machine
consists of a spinning table for
finished product on pallets to be
wrapped in stretch wrap. There are
a number of hazards associated
with this type of machine. There is
the potential for crushing hazards,
pinch-point hazard, and thermal
hazard. All of these can lead to broken
bones, potential amputation
and burns if not addressed properly
with safety measures. In order
to protect people from these hazards,
safety light curtains can be
implemented at the entrance and
exit of the machine with a requestto-enter
locked door. When someone
requests to enter, the rotating
arm that wraps the product will stop
moving when the door is opened.
Filter press. The filter press machine
consists of frames of cloth filters that
remove solids. The frames become
full of the solids and must be manually
cleaned. This is a high frequency
activity carried out by workers of the
global chemical company. Hazards
associated with this machinery include
crushing hazards, nip-point
hazards and impact hazards. These
have the potential for amputation or
fractures of limbs. These safety hazards
will be addressed to ensure the
continued safety of workers. This
is done by using a moveable interlock
guard to provide access to the
machine, but still allowing access to
the machine when necessary. When
someone enters the
work
area,
an output indicates a stop to the
FIGURE 4. Chemical products are loaded onto
pallets for shipping. This process carries the risk
for personnel injuries and product loss if certain
preventative measures are not taken
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Chemical Engineering August 2022
Table of Contents for the Digital Edition of Chemical Engineering August 2022
Chemical Engineering August 2022 - Intro
Chemical Engineering August 2022 - Cover1
Chemical Engineering August 2022 - Cover2
Chemical Engineering August 2022 - 1
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