105 CMR 120.228
Control of Access to Very High Radiation Areas
(A) In addition to the requirements in 105 CMR 120.227, the licensee or registrant shall
institute measures to ensure that an individual is not able to gain unauthorized or inadvertent
access to areas in which radiation levels could be encountered at five grays (500 rads) or more
in one hour at one meter from a source of radiation or any surface through which the radiation
penetrates at this level. This requirement does not apply to rooms or areas in which diagnostic
x-ray systems are the only source of radiation.
(B) The registrant is not required to control entrance or access to rooms or other areas
containing sources of radiation capable of producing a very high radiation area as described in
105 CMR 120.228(A) if the registrant has met all the specific requirements for access and
control specified in other applicable parts of 105 CMR 120.000, such as, 105 CMR 120.300 for
industrial radiography, 105 CMR 120.430 for x-rays in the healing arts, and 105 CMR 120.700
for particle accelerators.