[Code of Federal Regulations]
[Title 21, Volume 8]
[Revised as of April 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR1030.10]
 
[Page 628-631]
 
                        TITLE 21--FOOD AND DRUGS
 
CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN 
                          SERVICES (CONTINUED)
 
PART 1030--PERFORMANCE STANDARDS FOR MICROWAVE AND RADIO FREQUENCY EMITTING PRODUCTS--Table of Contents
 
Sec. 1030.10  Microwave ovens.
 
    (a) Applicability. The provisions of this standard are applicable to 
microwave ovens manufactured after October 6, 1971.
    (b) Definitions. (1) Microwave oven means a device designed to heat, 
cook, or dry food through the application of electromagnetic energy at 
frequencies assigned by the Federal Communications Commission in the 
normal ISM heating bands ranging from 890 megahertz to 6,000 megahertz. 
As defined in this standard, "microwave ovens" are limited to those 
manufactured for use in homes, restaurants, food vending, or service 
establishments, on interstate carriers, and in similar facilities.
    (2) Cavity means that portion of the microwave oven in which food 
may be heated, cooked, or dried.
    (3) Door means the movable barrier which prevents access to the 
cavity during operation and whose function is to prevent emission of 
microwave energy from the passage or opening which provides access to 
the cavity.
    (4) Safety interlock means a device or system of devices which is 
intended to prevent generation of microwave energy when access to the 
cavity is possible.
    (5) Service adjustments or service procedures means those servicing 
methods prescribed by the manufacturer for a specific product model.
    (6) Stirrer means that feature of a microwave oven which is intended 
to provide uniform heating of the load by constantly changing the 
standing wave pattern within the cavity or moving the load.
    (7) External surface means the outside surface of the cabinet or 
enclosure provided by the manufacturer as part of the microwave oven, 
including doors, door handles, latches, and control knobs.
    (8) Equivalent plane-wave power density means the square of the 
root-mean-square (rms) electric field strength divided by the impedance 
of free space (377 ohms).
    (c) Requirements--(1) Power density limit. The equivalent plane-wave 
power density existing in the proximity of the external oven surface 
shall not exceed 1 milliwatt per square centimeter at any point 5 
centimeters or more from the external surface of the oven, measured 
prior to acquisition by a purchaser, and, thereafter, 5 milliwatts per 
square centimeter at any such point.
    (2) Safety interlocks. (i) Microwave ovens shall have a minimum of 
two operative safety interlocks. At least one operative safety interlock 
on a fully assembled microwave oven shall not be operable by any part of 
the human body, or any object with a straight insertable length of 10 
centimeters. Such interlock must also be concealed, unless its actuation 
is prevented when access to the interlock is possible. Any visible 
actuator or device to prevent actuation of this safety interlock must 
not be removable without disassembly of the oven or its door. A 
magnetically operated interlock is considered to be
 
[[Page 629]]
 
concealed, or its actuation is considered to be prevented, only if a 
test magnet held in place on the oven by gravity or its own attraction 
cannot operate the safety interlock. The test magnet shall be capable of 
lifting vertically at zero air gap at least 4.5 kilograms, and at 1 
centimeter air gap at least 450 grams when the face of the magnet, which 
is toward the interlock when the magnet is in the test position, is 
pulling against one of the large faces of a mild steel armature having 
dimensions of 80 millimeters by 50 millimeters by 8 millimeters.
    (ii) Failure of any single mechanical or electrical component of the 
microwave oven shall not cause all safety interlocks to be inoperative.
    (iii) Service adjustments or service procedures on the microwave 
oven shall not cause the safety interlocks to become inoperative or the 
microwave radiation emission to exceed the power density limits of this 
section as a result of such service adjustments or procedures.
    (iv) Microwave radiation emission in excess of the limits specified 
in paragraph (c)(1) of this section shall not be caused by insertion of 
an insulated wire through any opening in the external surfaces of a 
fully assembled oven into the cavity, waveguide, or other microwave-
energy-containing spaces while the door is closed, provided the wire, 
when inserted, could consist of two straight segments forming an obtuse 
angle of not less than 170 degrees.
    (v) One (the primary) required safety interlock shall prevent 
microwave radiation emission in excess of the requirement of paragraph 
(c)(1) of this section; the other (secondary) required safety interlock 
shall prevent microwave radiation emission in excess of 5 milliwatts per 
square centimeter at any point 5 centimeters or more from the external 
surface of the oven. The two required safety interlocks shall be 
designated as primary or secondary in the service instructions for the 
oven.
    (vi) A means of monitoring one or both of the required safety 
interlocks shall be provided which shall cause the oven to become 
inoperable and remain so until repaired if the required safety 
interlock(s) should fail to perform required functions as specified in 
this section. Interlock failures shall not disrupt the monitoring 
function.
    (3) Measurement and test conditions. (i) Compliance with the power 
density limit in paragraph (c)(1) of this section shall be determined by 
measurement of the equivalent plane-wave power density made with an 
instrument which reaches 90 percent of its steady-state reading within 3 
seconds, when the system is subjected to a step-function input signal. 
Tests for compliance shall account for all measurement errors and 
uncertainties to ensure that the equivalent plane-wave power density 
does not exceed the limit prescribed by paragraph (c)(1) of this 
section.
    (ii) Microwave ovens shall be in compliance with the power density 
limits if the maximum reading obtained at the location of greatest 
microwave radiation emission, taking into account all measurement errors 
and uncertainties, does not exceed the limit specified in paragraph 
(c)(1) of this section, when the emission is measured through at least 
one stirrer cycle. As provided in Sec. 1010.13 of this chapter, a 
manufacturer may request alternative test procedures if, as a result of 
the stirrer characteristics of a microwave oven, such oven is not 
susceptible to testing by the procedures described in this paragraph.
    (iii) Measurements shall be made with the microwave oven operating 
at its maximum output and containing a load of 275 15 
milliliters of tap water initially at 20 5  deg.centigrade 
placed within the cavity at the center of the load-carrying surface 
provided by the manufacturer. The water container shall be a low form 
600-milliliter beaker having an inside diameter of approximately 8.5 
centimeters and made of an electrically nonconductive material such as 
glass or plastic.
    (iv) Measurements shall be made with the door fully closed as well 
as with the door fixed in any other position which allows the oven to 
operate.
    (4) User instructions. Manufacturers of microwave ovens to which 
this section is applicable shall provide, or cause to be provided, with 
each oven, radiation safety instructions which:
    (i) Occupy a separate section and are an integral part of the 
regularly supplied users' manual and cookbook, if
 
[[Page 630]]
 
supplied separately, and are located so as to elicit the attention of 
the reader.
    (ii) Are as legible and durable as other instructions with the title 
emphasized to elicit the attention of the reader by such means as bold-
faced type, contrasting color, a heavy-lined border, or by similar 
means.
    (iii) Contain the following wording:
 
  Precautions To Avoid Possible Exposure To Excessive Microwave Energy
 
    (a) Do not attempt to operate this oven with the door open since 
open-door operation can result in harmful exposure to microwave energy. 
It is important not to defeat or tamper with the safety interlocks.
    (b) Do not place any object between the oven front face and the door 
or allow soil or cleaner residue to accumulate on sealing surfaces.
    (c) Do not operate the oven if it is damaged. It is particularly 
important that the oven door close properly and that there is no damage 
to the: (1) Door (bent), (2) hinges and latches (broken or loosened), 
(3) door seals and sealing surfaces.
    (d) The oven should not be adjusted or repaired by anyone except 
properly qualified service personnel.
 
    (iv) Include additional radiation safety precautions or instructions 
which may be necessary for particular oven designs or models, as 
determined by the Director, Center for Devices and Radiological Health 
or the manufacturer.
    (5) Service instructions. Manufacturers of microwave ovens to which 
this section is applicable shall provide or cause to be provided to 
servicing dealers and distributors and to others upon request, for each 
oven model, adequate instructions for service adjustments and service 
procedures, and, in addition, radiation safety instructions which:
    (i) Occupy a separate section and are an integral part of the 
regularly supplied service manual and are located so as to elicit the 
attention of the reader.
    (ii) Are as legible and durable as other instructions with the title 
emphasized so as to elicit the attention of the reader by such means as 
bold-faced type, contrasting color, a heavy-lined border, or by similar 
means.
    (iii) Contain the following wording:
 
Precautions To Be Observed Before And During Servicing To Avoid Possible 
                 Exposure To Excessive Microwave Energy
 
    (a) Do not operate or allow the oven to be operated with the door 
open.
    (b) Make the following safety checks on all ovens to be serviced 
before activating the magnetron or other microwave source, and make 
repairs as necessary: (1) Interlock operation, (2) proper door closing, 
(3) seal and sealing surfaces (arcing, wear, and other damage), (4) 
damage to or loosening of hinges and latches, (5) evidence of dropping 
or abuse.
    (c) Before turning on microwave power for any service test or 
inspection within the microwave generating compartments, check the 
magnetron, wave guide or transmission line, and cavity for proper 
alignment, integrity, and connections.
    (d) Any defective or misadjusted components in the interlock, 
monitor, door seal, and microwave generation and transmission systems 
shall be repaired, replaced, or adjusted by procedures described in this 
manual before the oven is released to the owner.
    (e) A Microwave leakage check to verify compliance with the Federal 
performance standard should be performed on each oven prior to release 
to the owner.
 
    (iv) Include additional radiation safety precautions or instructions 
which may be necessary for particular oven designs or models, as 
determined by the Director, Center for Devices and Radiological Health 
or the manufacturer.
    (6) Warning labels. Except as provided in paragraph (c)(6)(iv) of 
this section, microwave ovens shall have the following warning labels:
    (i) A label, permanently attached to or inscribed on the oven, which 
shall be legible and readily viewable during normal oven use, and which 
shall have the title emphasized and be so located as to elicit the 
attention of the user. The label shall bear the following warning 
statement:
 
    Precautions For Safe Use To Avoid Possible Exposure To Excessive 
                            Microwave Energy
 
    DO NOT Attempt to Operate This Oven With:
    (a) Object Caught in Door.
    (b) Door That Does Not Close Properly.
    (c) Damaged Door, Hinge, Latch, or Sealing Surface.
 
    (ii) A label, permanently attached to or inscribed on the external 
surface of the oven, which shall be legible and
 
[[Page 631]]
 
readily viewable during servicing, and which shall have the word 
"CAUTION" emphasized and be so located as to elicit the attention of 
service personnel. The label shall bear the following warning statement:
 
    Caution: This Device is to be Serviced Only by Properly Qualified 
Service Personnel. Consult the Service Manual for Proper Service 
Procedures to Assure Continued Compliance with the Federal Performance 
Standard for Microwave Ovens and for Precautions to be Taken to Avoid 
Possible Exposure to Excessive Microwave Energy.
 
    (iii) The labels provided in accordance with paragraphs (c)(6)(i) 
and (ii) of this section shall bear only the statements specified in 
that paragraph, except for additional radiation safety warnings or 
instructions which may be necessary for particular oven designs or 
models, as determined by the Director, Center for Devices and 
Radiological Health or the manufacturer.
    (iv) Upon application by a manufacturer, the Director, Center for 
Devices and Radiological Health, Food and Drug Administration, may grant 
an exemption from one or more of the statements (radiation safety 
warnings) specified in paragraph (c)(6)(i) of this section. Such 
exemption shall be based upon a determination by the Director that the 
microwave oven model for which the exemption is sought should continue 
to comply with paragraphs (c) (1), (2), and (3) of this section under 
the adverse condition of use addressed by such precautionary 
statement(s). An original and two copies of applications shall be 
submitted to the Dockets Management Branch (HFA-305), Food and Drug 
Administration, rm. 1-23, 12420 Parklawn Dr., Rockville, MD 20857. 
Copies of the written portion of the application, including supporting 
data and information, and the Director's action on the application will 
be maintained by the Branch for public review. The application shall 
include:
    (a) The specific microwave oven model(s) for which the exemption is 
sought.
    (b) The specific radiation safety warning(s) from which exemption is 
sought.
    (c) Data and information which clearly establish that one or more of 
the radiation safety warnings in paragraph (c)(6)(i) of this section is 
not necessary for the specified microwave oven model(s).
    (d) Such other information and a sample of the applicable product if 
required by regulation or by the Director, Center for Devices and 
Radiological Health, to evaluate and act on the application.
 
[38 FR 28640, Oct. 15, 1973, as amended at 40 FR 14752, Apr. 4, 1975; 40 
FR 52007, Nov. 7, 1975; 46 FR 8461, Jan. 27, 1981; 48 FR 57482, Dec. 30, 
1983; 50 FR 13566, Apr. 5, 1985; 53 FR 11254, Apr. 6, 1988; 59 FR 14365, 
Mar. 28, 1994]