Current through Register Vol. 49, No. 13, September 23, 2024
Subpart
1.
General.
The containment must be provided with a HEPA-filter equipped
ventilation system.
Subp.
2.
HEPA-filter equipped negative air requirements.
The HEPA-filter negative air machine must be equipped
with:
A. a calibrated pressure gauge
to measure the pressure drop across the filter;
B. an audible alarm or an automatic unit
shutdown mechanism activated in the event of a breach in the filter or in the
absence of a filter;
C. an audible
alarm or automatic unit shutdown mechanism activated when the differential
pressure across the filter exceeds a preset pressure; and
D. an automatic electrical power cutoff
switch so the unit will not operate if the HEPA-filter is not present or not
positioned correctly.
Subp.
3.
Continuous operation of HEPA-filter equipped ventilation
system.
The HEPA-filter equipped ventilation system must operate
continuously from the time of asbestos disturbance until results of analysis of
the clearance samples indicate the air inside the containment is at or below
the clearance standard or the alternative clearance standard.
Subp. 4.
HEPA-filter equipped system
criteria.
The HEPA-filter equipped ventilation system must be operated
according to the criteria in this subpart.
A. The amount of air exhausted from the
containment must provide for at least four air changes per hour within the
containment.
B. A negative pressure
of at least 0.02 inches of water must be established and maintained within each
containment with respect to the area outside of the containment.
C. The negative pressure must be measured by
a recording manometer.
(1) The recording
manometer must be placed as far from the intake of the HEPA-filter equipped
ventilation system as possible.
(2)
The recording manometer must be placed to ensure that the reading is of the
containment's negative pressure.
(3) The recording manometer must be monitored
every two hours throughout all abatement work shifts to ensure continuous
recording operation.
(4) The
recording manometer must be zeroed before work begins each day.
(5) Each recording manometer must be
calibrated at least annually.
(6)
In the event of a failure of a recording manometer during a project, the
following actions must be taken:
(a) an
operating recording manometer must be placed in service within 24 hours of the
failure of the initial recording manometer;
(b) until an operating recording manometer is
placed in service, hourly pressure readings must be documented for all work
shifts; and
(c) documentation must
be available at the work site for each failure of the recording
manometer.
Subp. 5.
Inability to establish or
maintain a negative pressure of at least 002 inches of water.
If it is not possible to establish or maintain a negative
pressure of at least 0.02 inches of water in the containment with respect to
the pressure outside the containment for a period of 15 minutes, items A to D
apply in addition to the requirements of subpart 4, item C.
A. A pressure as close to negative 0.02
inches of water as possible must be maintained from the time construction of
the containment is completed until results from clearance air samples are
obtained.
B. The amount of air
exhausted from the containment must be increased to at least six air changes
per hour within the containment.
C.
Documentation must be available on site for each case of the failure to
establish negative pressure or each case of failure to maintain a pressure of
negative 0.02 inches of water in the containment with respect to the air
pressure outside the containment. The documentation must specify the:
(1) probable cause of failure to establish or
maintain the required negative air pressure;
(2) date of failure to establish or maintain
the required negative air pressure;
(3) times of failure to maintain the required
negative air pressure; and
(4) name
of the asbestos site supervisor in charge of the site at the time of failure to
establish or maintain the required negative air pressure in the containment
with respect to the air pressure outside the containment.
D. Specific methods used to reestablish a
negative pressure of at least 0.02 inches of water in the containment with
respect to the air outside the containment must be documented and available for
review on site.
Subp. 6.
HEPA-filtered ventilation system exhaust.
The HEPA-filter equipped ventilation system must be
positioned to exhaust filtered air to the outside of the facility. If it is not
technically feasible to exhaust the HEPA-filter equipped ventilation systems
outdoors, there must be air monitoring every four hours during abatement
activity in the vicinity of the HEPA-filter equipped ventilation system
exhaust.
Statutory Authority: MS s
144.05;
326.70 to
326.81
