delivered the opinion of the court:
The petitioner, the Board of Certified Safety Professionals of the Americas, Inc. (Board), is a not-for-profit corporation that issues certificates to safety professionals who pass examinations it conducts. In October 1981, the Board purchased land in Savoy, Illinois, on which it constructed its corporate office. In August 1982, the Board applied for a partial real estate tax exemption, which was denied by the Champaign County board of review in March 1983. The Illinois Department of Revenue affirmed the denial. On review of the Department’s decision, the Director of the Department again denied the Board’s request for a tax exemption.
*544The Board then filed a complaint for administrative review in the circuit court of Champaign County. The circuit court held that the legislative exemption for property used for “mechanical” purposes in section 19.10 of the Revenue Act of 1939 (Ill. Rev. Stat. 1983, ch. 120, par. 500.10) is unconstitutional because it exceeds the scope of article IX, section 6, of the Illinois Constitution of 1970 (Ill. Const. 1970, art. IX, sec. 6); that the record supported the Department’s finding that the Board’s property was not used exclusively or primarily for charitable or educational purposes; and that the denial of a tax exemption to the Board did not violate equal protection. The circuit court thus affirmed the Department’s decision and entered a judgment against the Board. Pursuant to Supreme Court Rule 302(a) (103 Ill. 2d R. 302(a)), the Board appealed directly to this court from the circuit court’s order declaring the statutory exemption for property used for mechanical purposes (Ill. Rev. Stat. 1983, ch. 120, par. 500.10) unconstitutional.
According to its articles of incorporation, the Board was established by the American Society of Safety Engineers in 1969 “[f]or charitable, scientific, and educational purposes and to promote the advancement of safety through the issuance of a certificate to any individual competent to be designated as a ‘Certified Safety Professional’ ***.” The Board is now sponsored by four organizations: the American Society of Safety Engineers, the American Industrial Hygiene Association, the Systems Safety Society, and the Society of Fire Protection Engineers.
To achieve its purposes, the Board offers an examination twice a year at 25 to 30 locations throughout the United States and overseas. The exam is prepared in conjunction with another organization known as the Professional Examination Service and consists of two parts: a core exam covering six areas of knowledge (basic and *545applied sciences, safety-program management and evaluation, fire prevention and protection, equipment and facilities, environmental agents, and systems product safety), and an advanced exam leading to certification as a “safety professional” in one of five categories (comprehensive practice, engineering, management, systems safety, or products safety). The core exam may be taken by any applicant who has achieved the required academic training in the field of safety and has at least one year of professional safety experience. If an applicant is currently a registered professional engineer or is certified by the American Board of Industrial Hygiene or the American Board of Health Physics, the core exam is waived. Only a person who has passed the core exam or who meets the criteria for waiver may take the advanced exam and be certified as a “safety professional.” The Board charges a fee to take an exam, to retake a section that an applicant has failed, and to renew a certification.
There are currently about 5,500 safety professionals in good standing residing in all 50 States and 16 foreign countries, 358 of whom live in Illinois. In addition to the preparation and administration of the exams, the Board maintains a library of standards and publications relating to the safety profession and publishes a newsletter three times a year.
The Board contends that its property is exempt from taxation because its activities fall within the statutory exemption for property used for school “or other educational purposes” (Ill. Rev. Stat. 1983, ch. 120, par. 500.1). Relying on Association of American Medical Colleges v. Lorenz (1959), 17 Ill. 2d 125, the Board argues that a taxpayer need not be a school offering classroom instruction to qualify for an exemption for “educational purposes,” and that, like the taxpayer in American Medical Colleges, the Board uses its property to improve ed*546ucational standards in its field, to publish newsletters, to administer examinations, and to maintain a library of relevant material.
However, the Board’s reliance on American Medical Colleges is misplaced. The holding in that case was that an organization that is created by tax-exempt institutions that join together to function more efficiently is also entitled to an exemption. (See Association of American Medical Colleges v. Lorenz (1959), 17 Ill. 2d 125, 129.) In the present case, the organizations that sponsor the Board are not themselves tax exempt. Moreover, since the State does not license or register safety professionals, the Board’s'activities do not “ ‘substantially lessen[ ] what would otherwise be a governmental function and obligation.’ ” (Milward v. Paschen (1959), 16 Ill. 2d 302, 308.) The Board cannot claim an exemption for activities that would not entitle its sponsors to an exemption. Thus, the Board does not meet the requirements for an exemption for property used for educational purposes.
Similarly, the Board’s contention that it is entitled to a tax exemption because its property is used exclusively for charitable purposes (Ill. Rev. Stat. 1983, ch. 120, par. 500.7) must fail. The criteria for determining whether an organization qualifies for this exemption as set out in Methodist Old Peoples Home v. Korzen (1968), 39 Ill. 2d 149, 156-57, include the requirements that the organization benefit the public at large, reduce the burdens of government, and derive its funds from public and private charity. However, the Board’s activities benefit primarily a particular class of people, namely safety professionals, and only indirectly the general public. Moreover, the public benefits of the activities of the members of the safety profession are the result of services rendered by those members, who would perform the same function with or without Board certification. Further, the Board’s *547activities do not reduce the State’s burdens since, as noted above, the State does not license or register safety-professionals. Finally, the Board derives its funds from examination and renewal fees, and not from public or private charity.
The Board next contends that the legislative exemption for property used for “mechanical” purposes in section 19.10 of the Revenue Act of 1939 (Ill. Rev. Stat. 1983, ch. 120, par. 500.10) is constitutional and applicable to its property. According to the Board, the word “mechanical” has historically denoted “scientific” or “related to the study of engineering.” Because its primary function consists of certifying persons educated in various fields of science and technology, the Board argues that its property falls within the statutory exemption for property used for “mechanical” purposes. Further, the Board argues, the respondents have failed to overcome the presumption of constitutionality that must be accorded to legislative enactments (Livingston v. Ogilvie (1969), 43 Ill. 2d 9, 12), and have failed to sustain their burden of showing that the statute is invalid (Pozner v. Mauck (1978), 73 Ill. 2d 250, 255).
However, statutes granting tax exemptions must be construed strictly in favor of taxation (Coyne Electrical School v. Paschen (1957), 12 Ill. 2d 387, 390), and the party claiming an exemption has the burden of proving clearly and conclusively that the property in question falls within both the constitutional authorization and the terms of the statute under which the exemption is claimed (Coyne Electrical School v. Paschen (1957), 12 Ill. 2d 387, 390; People ex rel. Kelly v. Avery Coonley School (1957), 12 Ill. 2d 113, 115). In the present case, the Board has not met its burden.
Article IX, section 6, of the 1970 Illinois Constitution provides in pertinent part:
*548“The General Assembly by law may exempt from taxation only *** property used exclusively for *** school, religious, cemetery and charitable purposes.” (Ill. Const. 1970, art. IX, sec. 6.)
The language used to describe property that is eligible for exemption with appropriate legislation does not authorize an exemption for “mechanical purposes.” In International College of Surgeons v. Brenza (1956), 8 Ill. 2d 141, this court struck down a legislative exemption for property used for “philosophical” purposes. Similarly, we hold an exemption for property used for “mechanical” purposes invalid because such an exemption exceeds the scope of article IX, section 6, of our constitution. Even if “mechanical purposes” is deemed a subcategory of “scientific purposes,” the exemption is still invalid because the constitution does not authorize an exemption for property used for scientific purposes, either.
Finally, the Board argues that denying its claim to a tax exemption violates equal protection because it is similarly situated to other organizations that have been granted tax-exempt status. However, in the cases cited by the Board, the court found that the taxpayers were entitled to a constitutionally authorized statutory exemption. In this respect, the Board is not similarly situated to those organizations, and its equal protection argument must therefore fail.
For the foregoing reasons, the judgment of the circuit court is affirmed.
Judgment affirmed.