Specifications

Ver SG 9/200 17 Sharp Electronics Corporation
____________________________________________________
Microwave Safety
____________________________________________________
Public Law 90-602, the Radiation Control for Health and Safety Act of 1968 was passed
by Congress, October 18, 1968. One of the purposes of this law was to establish
standards for various electronic products’ radiation so that the public could not be
exposed unnecessarily to excessive amounts of radiation of various kinds given off by
these products. Items such as television sets, sun lamps, microwave ovens and various
other products are covered by this law. Standards for microwave ovens went into effect
October 6, 1971. Under these standards, radiation leakage from microwave ovens cannot
exceed one (1) milliwatt per square centimeter (mW/cm
2
) measured two (2) inches from
the oven prior to factory release, and five (5) mW/cm
2
thereafter. The measuring
equipment to be used is also specified in the standards.
Before the standard for microwave ovens went into effect, industry had operated with a
voluntary standard 10mW/cm
2
. Standards were established in order to protect
technicians working around radar sites from being exposed to possibly dangerous levels
of microwave radiation. Experiments with animals had shown that continuous exposure
at relatively high levels of radiation could raise body temperature to a fatal level. The
10mW/cm
2
standard had a considerable margin of safety built in. This standard for radar
workers was based on what is called “whole body” radiation: that is, conditions under
which each square centimeter of the body is exposed to radiation. It is said that body
temperature will rise 1°F. if exposed long enough at this power level. By way of
contrast, solar energy reaching the Earth on a sunny day may be 60 to 100 mW/cm
2
.
Staring at the sun represents a far greater hazard than exposure to 10 mW/cm
2
of
microwave radiation. Serious eye damage, even blindness has been known to occur from
improper observation of a solar eclipse. On the other hand, microwave diathermy at the
same frequency used in microwave ovens is used for treatment of certain eye diseases.
The level of energy employed is much greater than 10mW/cm
2
and for periods longer
than one would stand in front of a microwave oven. Dr. James Ban Allen, a well known
authority of radiation technology has expressed the microwave hazard from the operation
of a microwave oven, as “about the same as the likelihood of getting a skin tan from
moonlight.” Even the Surgeon General of the United States has publicly stated that no
injuries from microwave oven use have been reported.