Texas Air Control Board
              Austin                       Texas
                           Memorandum

To:  Combustion Permit Engineers and Regional Directors
From:  Jim Crocker, P.E., Director, Combustion Division
Date:  May 9, 1991
Subject:  Best Available Control Technology (BACT) For Small
          On-site Medical Waste Incinerators

It has come to my attention that there is some confusion
between Regulation I requirements and BACT requirements for
newly permitted, on-site medical waste incinerators.  The
following information is intended to set forth the position of
the Combustion Division of the Permits Program.

As you are aware, Rule 116.110(a) requires all new facilities
to either obtain a permit to construct or satisfy the
conditions for exempt facilities.  The only standard exemption
that is applicable for the incineration of any type of medical
waste is Standard Exemption No. 90 (SE 90).  SE 90 allows for
the incineration of pathological waste (Type IV) only. 
Because of the restricted nature of the definition of
pathological waste, SE 90 is used in only very limited
applications.  All other facilities that burn medical waste
must obtain a construction permit before the facility is
constructed.  Rule 116.111(3) requires that a facility must
utilize BACT before a permit to construct can be granted.  At
this time, BACT guidelines for on-site medical waste
incinerators with a capacity of less than 225 pounds per hour
require no add-on controls, such as scrubbers or baghouses,
unless the atmospheric dispersion modeling predicts
exceedances of TACB effects screening levels, property line
standards or national ambient air quality standards.  However,
these facilities are not exempt from all control requirements. 
BACT guidelines for permitted units less than 225 pounds per
hour require process controls such as:

1.  Secondary chamber temperature of 1800F minimum,
2.  Secondary chamber retention time of one second minimum and
3.  Particulate matter emissions not to exceed 0.08 grains per
      dry standard cubic foot, corrected to seven percent
      oxygen, front- and back-half of the sampling train.

Regardless of the type of Regulation VI authorization, all
pathological and medical waste incinerators must meet the
requirements of Regulation I.