In July 1997, Health Canada distributed a “Proposed Revision of Safety Code 6” amending its guidelines for evaluating the enviromnental effects of radio frequency (RF) electromagnetic ﬁelds. One of the areas discussed in Safety Code 6, and which Industry Canada is implementing, is compliance with the limits for safe exposure to RF emissions due to mobile and portable devices such as non-ﬁxed wireless transmitte|rs and hand-held cellular telephones. The new Health Canada guidelines differentiate between portable and mobile devices according to their proximity to exposed persons. For portable devices, RP evaluation must be based on speciﬁc absorption rate (SAR) limits. Human expostue to RF emissions ﬁ’om mobile devices can be evaluated with respect to Maximum Permissible Exposure (MPE) limits for ﬁeld strength or power density or with respect to SAR limits, whichever is most appropriate. The purpose of this document is to provide parties ﬁling applications for equipment authorization with guidance on complying with the new SAR requirements.
Currently, industry groups and other organizations are working to develop standardized product test procedures to evaluate RF exposure compliance with MPE and SAR limits.‘ Future revisions of this document may be issued, as appropriate. The Industry Canada rules require applicants for equipment authorization of certain portable and mobile devices to include an affirmative statement of compliance attesting that the devices comply with Health Canada limits for RF exposure. The rules also require that teclmical information be provided upon request for supporting compliance.
Sometimes it may be necessary to request certain technical data to support test procedures. A list of technical items that are normally used to evaluate SAR compliance will be developed to provide applicants with guidance on the type of information that is generally applicable for substantiating compliance.
Mobile and portable transmitting devices that operate in the Cellular Radiotelephone Services, the Personal Commtmications Services (PCS), the Satellite Commtmications Services, the General Wireless Communications Service, the Wireless Communications Service, the Maritime Services (ship earth stations only) and Specialized Mobile Radio Services are subject to routine environmental evaluation for RP exposure prior to equipment authorization or use. Unlicensed PCS, U-NII and millimeter Wave devices authorized by Industry Canada rules are also subject to routine environmental evaluation for RF exposure prior to equipment authorization or use. All of the above devices are covered by their respective Radio Speciﬁcation Standards (RSS series). For the purposes of RF exposure evaluation, a. mobile device is deﬁned as a transmitting device designed to be used in other than ﬁxed locations and to be generally used in such a way that a. separation distance of at least 20 centimeters is normally maintained between the transmitter’s radiating structures and the body of the user or nearby persons. In this context, the term “ﬁxed location” means that the device, including its anterma, is physically secured at one location and is not able to be easily moved to another location. Examples of mobile devices, as deﬁned above, would include cellular and PCS mobile telephones, other radio devices that use vehicle-mormted antemras and certain other transportable transmitting devices. Transmitting devices designed to be used by consumers or workers that can be easily re-located, such as Wireless devices associated with a personal computer and transportable cellular telephones (“bag” phones), are considered to be mobile devices if they meet the 20 centimeter separation requirement. These devices are normally evaluated for exposme potential with MPE. Mobile devices may also be evaluated with respect to the SAR limits given for RF exposrue compliance, but in such cases it is usually simpler and more cost-effective to evaluate compliance with respect to MPE limits based on ﬁeld strength or power density. Detailed SAR limits are given in the Safety Code 6 (draft). The most stringent are limits for general population and they include in section 2.3 below. SAR limits for general population are the base for certiﬁcation for the SAR.
All RF handheld commrmication devices operating at the distance of less than 200 mm ﬁom human body have to be certiﬁed to these requirements for non-ionizing radiation safety. Certiﬁcation should be based on measurements of SAR, unless a device is speciﬁcally exempt and shown to be safe by computations according to allowance for computational certiﬁcation (see Section 2.5 of this report). 0 General – spatial peak SAR not exceeding 1.6 W/kg averaged over 1 gram of tissue deﬁned as a tissue volume in shape of a cube 0 Hands, wrist, feet, ankles – spatial peak SAR not exceeding 4 W/kg averaged over 10 grams of tissue defmed as a tissue volume in shape of a cube 0 Eye – peak SAR not exceeding 0.2 W/kg averaged over eye volume.
With respect to SAR evaluation, the 1997 Health Canada exposure criteria, upon which the Industry Canada guidelines are based, recommend limits with respect to both
occupational/controlled and general population/rmcontrolled exposures. The compliance requirements for each category are based on a person’s awareness and ability to exercise
control over his or her exposure. In general, the occupational/controlled exposure limits are applicable to situations in which persons are exposed as a consequence of their employment, have been made fully aware of the potential for exposure and can exercise control over their exposure. This exposure category is also applicable when the exposure is of a transient nature due to incidental
passage through a location where the exposure levels may be higher than the general population/rmcontrolled limits, but the exposed person is fully aware of the potential for exposure and can exercise control over his or her exposure by leaving the area or by some other appropriate means. Awareness of the potential for RF exposure in a workplace or similar environment can be provided through speciﬁc training as part of an RF safety program. If appropriate, waming signs and labels can also be used to establish such awareness by providing prominent information on the risk of potential exposure and instructions on methods to minimize such exposure risks. The general population/uncontrolled exposure limits are applicable to situations in which the general public may be exposed or in which the persons who are exposed as a consequence of their employment may not be made fully aware of the potential for exposure or cannot exercise control over their exposure. Members of the general public would come rmder this category when exposure is not employment-related, for example, in the case of a wireless transmitter that exposes persons in its vicinity. Warning labels placed on low-power consumer devices such as cellular telephones are not considered sufﬁcient to allow the device to be considered rmder the occupational/controlled category, and the general population/uncontrolled exposure limits apply to these devices.