This case is before this court pursuant to Section 6(f) of the Occupational Safety and Health Act of 1970 (“Act”), 29 U.S.C. § 655(f).1 The Forging Industry Association (“FIA”) petitions this court to review *212the Secretary of Labor’s promulgation of a “hearing conservation amendment” (“amendment”) to its occupational noise exposure standard, 29 C.F.R. § 1910.95 (“standard”). Finding that the Department of Labor’s Occupational Safety and Health Administration (OSHA) exceeded its authority in adopting the amendment, we vacate the amendment and remand.
I
An occupational noise exposure standard has existed since OSHA’s inception in 1971. The current standard, which is found at 29 C.F.R. § 1910.95, was originally promulgated under the Walsh-Healey Public Contracts Act, 41 U.S.C. § 35 et seq. for the purpose of protecting employees from workplace exposure to damaging levels of noise. The Walsh-Healey standard was adopted by OSHA pursuant to Section 6(a) of the Occupational Safety and Health Act, which allowed the Secretary to promulgate any established Federal standard within two years of the effective date of the Act without regard to established rulemaking procedure.
The standard establishes a permissible workplace limit of 90 decibels (db)2 calculated using an 8-hour time-weighted average.3 29 C.F.R. § 1910.95(a). If the 90 db exposure limit is exceeded, the employer must reduce noise to or below this level by using feasible engineering or administrative controls.4 Id. at § 1910.95(b)(1). If such controls are infeasible, employers may use hearing protectors, such as ear muffs or plugs, to reduce employee noise exposure to permissible limits. Id. Prior to amendment, the standard also contained a generally phrased requirement that employers administer “a continuing effective hearing conservation program” in workplaces where sound levels exceeded the permissible exposure level. Id. at § 1910.-95(b)(3) (1980).
When studies revealed that many employees suffered significant hearing impairment at noise levels below the 90 db threshold, OSHA began the process of collecting and evaluating the information necessary to issue a comprehensive new regulation with a reduced permissible exposure level of 85 db. As an interim measure, OSHA adopted a hearing conservation amendment to replace the general conservation program requirement.
Despite its interim nature the requirements of the amendment are substantial. The amendment requires employers to determine which employees are exposed to or above an “action level” of 85 db measured as an 8-hour time-weighted average. 29 C.F.R. 1910.95(d). Such employees must be notified of the amount of sound they are exposed to and provided with an audiome-tric test to determine their hearing level. Id. at 1910.95(e), (g)(1). At least annually thereafter, the employer must provide the exposed employee with an additional test to determine whether the employee has suffered an average loss of hearing of 10 db, known as a standard threshold shift, or *213“STS.”5 Id. at § 1910.95(g)(6). If there has been an STS, the employer must take follow-up measures to prevent the employee from reaching the material impairment stage. These measures include fitting the employee with hearing protectors, providing training, and requiring the employee to use the protectors. Id. at 1910.95(g)(8). The protectors must reduce the employee’s exposure to an 8-hour TWA of 85 db or below. Id. at 1910.95(j)(3).
In addition, the employer must institute a training program on audiometric testing, hearing protectors, and effects of noise on hearing for all employees who are exposed to noise at or above an 8-hour TWA of 85 db. Id. at 1910.95(k). The employer must also retain records of employee exposure measurements and audiometric tests. Id. at 1910.95(m).
The provisions of the amendment apply to all employees covered by the Act, except those in construction, agriculture, and oil and gas well drilling and servicing. 46 Fed.Reg. 42622. OSHA estimates the annual cost of compliance for the amendment at $254,321,000.00. Final Regulatory Analysis of the Hearing Conservation Amendment, U.S. Department of Labor, Occupational Safety and Health Administration, Office of Regulatory Analysis (January 1981), part IV.
II
An initial inquiry that must be made in determining the validity of any regulation adopted by a federal agency is whether the regulation is within the scope of the agency’s statutory authority. Citizens to Preserve Overton Park, Inc. v. Volpe, 401 U.S. 402, 415, 91 S.Ct. 814, 823, 28 L.Ed.2d 136 (1971). Examining the language of the Occupational Safety and Health Act and the Supreme Court decisions interpreting it, we find it clear that Congress only authorized the Secretary to adopt those standards which relate to health and safety at the workplace.
The Act in its statement of findings and declaration of purpose and policy refers repeatedly to “working conditions”. 29 U.S.C. § 651(b). The Act defines the term “occupational safety and health standard” as “a standard which requires conditions ... reasonably necessary or appropriate to provide safe or healthful employment and places of employment.” (emphasis added). 29 U.S.C. § 652(8).
In addition, the Supreme Court stated in the first OSHA case it considered that: “The Act created a new statutory duty to avoid maintaining unsafe or unhealthy working conditions.” Atlas Roofing Co. v. OSAHRC, 430 U.S. 442, 445, 97 S.Ct. 1261, 1264, 51 L.Ed.2d 464 (1977) (emphasis added). In later cases, the Court further defined the scope of the Secretary’s authority under the Act. “[BJefore he can promulgate any permanent health or safety standard [emphasis in the original], the Secretary is required to make a threshold finding that a place of employment is unsafe.” Industrial Union Department v. American Petroleum Institute, 448 U.S. 607, 642, 100 S.Ct. 2844, 2864, 65 L.Ed.2d 1010 (emphasis added). Congress placed pre-eminent value on assuring employees “a safe and healthy working environment.” American Textile Mfrs. Institute v. Donovan, 452 U.S. 490, 540, 101 S.Ct. 2478, 2506, 69 L.Ed.2d 185 (1981) (emphasis added).
Most importantly, given the vast number of factors outside of the workplace that can potentially affect an employee’s health or safety (e.g. social and recreational activities, alcohol or drug use, defective eonsum*214er products), interpreting the Act to extend to hazards existing outside the workplace would place under OSHA’s control areas already subject to regulation by other federal agencies (the Alcohol, Drug Abuse and Mental Health Administration, the Consumer Product Safety Commission, the Environmental Protection Agency, the Food and Drug Administration and the National Highway Traffic Safety Administration to name but a few).
In light of the foregoing, we follow the approach of the Eleventh Circuit which is that “the conditions to be regulated [by OSHA] must fairly be considered working conditions, the safety and health hazards to be remedied occupational, and the injuries to be avoided work-related,.” Frank Diehl Farms v. Secretary of Labor, 696 F.2d 1325, 1332 (11th Cir.1983) (emphasis in the original) (OSH Act does not extend to hazards associated with housing provided to seasonal farm employees unless such housing is a condition of employment).
A standard is invalid if it requires an employer to take actions in regard to hazards existing outside the workplace. It is clear from the languge of the hearing conservation amendment, as well as the record before this court, that under the amendment employers may be subjected to requirements and penalties may be imposed as a result of non-workplace hazards. The amendment’s requirements are triggered whenever an employee suffers a standard threshold shift loss in hearing. It is obvious that such a hearing loss can result from non-oecupational noise exposure just as easily as it can from occupational exposure.6 Airplanes, hunting rifles, loud music and a myriad of other sources produce noise potentially as damaging as any at the workplace. Yet the Amendment makes no distinction between hearing loss caused by workplace sources and loss caused by non-workplace sources. The rule-making record clearly provides that once a hearing loss is found, the amendment requires the same actions by the employer “whether or not the [loss] is work-related,” 48 Fed.Reg. 9764/2, and that the subject rule contains no requirement that there be “a determination of work relatedness.”7 Id. at 9678/1.
Thus the hearing conservation amendment clearly imposes responsibilities on employers based on non-work-related hazards. Under the amendment, an employer whose workers are unaffected by work*215place noise may be subject to numerous requirements simply because its workers choose to hunt, listen to loud music or ride motorcycles during their non-working hours. Hearing loss caused by such activities is regrettable but it is not a problem that Congress delegated to OSHA to remedy. The amendment is therefore vacated and remanded to OSHA for the creation of a valid standard.
VACATED AND REMANDED.
. Section 655(f) provides that:
Any person who may be adversely affected by a standard issued under this section may at any time prior to the sixtieth day after such standard is promulgated file a petition challenging the validity of such standard with the United States court of appeals for the circuit wherein such person resides or has his principal place of business, for a judicial review of such standard.....
. Decibels are a measure of sound loudness. The entire spectrum of audible sound pressure can be compressed into a logarithmic scale of 0 to 140 db. Hertz ("Hz”), in contrast, measure the frequency of sound. Frequency is determined by the number of times that a complete cycle of compressions and expansions occurs in a second. The audible range of frequencies for people with good hearing is 20 Hz to 20,000 Hz.
. The time-weighted average (TWA) combines noise level and duration of exposure to measure the accumulation of noise levels experienced by an employee over a workshift. OSHA computes the relationship between noise level and exposure time by using a 5 db "exchange rate.” This means that for each 5 db increase in noise level, the exposure time must be cut in half. For example, an employee who works for 4 hours in continuous noise of 95 db would be exposed to an 8 hour TWA of 90 db, as would an employee exposed to 100 db for 2 hours. 46 Fed.Reg. 4080/1; 29 C.F.R. § 1910.95, Table G-16.
. Engineering controls involve modification of plant, equipment, processes, or materials to reduce noise; for example, adding a muffler to a vehicle. Administrative controls involve modification of work assignments to reduce employee exposure to noise; for example, rotating employees so that they work in noisy areas for a short time. 48 Fed.Reg. 7473/3.
. Hearing loss is measured by an audiometer. Audiometers produce pure tones at specific frequencies (e.g., 250, 500, 1000, 2000, 3000, 4000, 6000, and 8000 Hz) and at specific sound levels. The record of a given individual’s hearing sensitivity is called an audiogram. An audiogram shows hearing threshold level measured in decibels as a function of frequency in hertz. It indicates how intense or loud a sound at a given frequency must be before it can be perceived. Thus under the amendment, follow up measures are required whenever the quietest sound an employer can hear at 2000, 3000 and 4000 hz is an average 10 db louder than it was when the baseline audiometric test was performed.
. As the Department of Labor itself acknowl-. edges:
There are few places you can go now to escape it. In any urban area, large or small, it’s the roar of traffic, the thud of a pile driver, the staccato of a pneumatic drill, the shriek of a fire engine, the blast of a motorcycle, the blare of a rock and .roll group, the whine of a jet overhead. Noise has become an inescapable component of modern, mechanized life.
Noise. The Environmental Problem. A Guide to OSHA Standards U.S. Department of Labor, Occupational Safety and Health Administration (OSHA 2067) (reprinted from the July-August issue of Safety Standards magazine).
. In a letter to this Court following oral argument, the Secretary refers to Section 8(g)(8)(ii) of the Amendment in support of his contention that the requirements of the hearing conservation amendment are not triggered by non-occupational noise. Section 8(g)(8)(ii) provides (emphasis added)
Unless a physician determines that the standard threshold shift is not work related or aggravated by occupational noise exposure, the employer shall ensure that the following steps are taken when a standard threshold shift occurs . . . .
This clause is of little effect. An earlier draft of the amendment required that the professional reviewing employee audiograms determine whether any significant threshold shifts detected were caused by occupational noise exposure. In deleting this requirement in the final version, OSHA emphasizes:
Commenters stated that in some cases it is very difficult, even for an audiologist or oto-laryngologist, to determine the cause, or work relatedness, of a significant threshold shift because of the similarity between an occupational and nonoccupational audiometric hearing loss configuration on the audiogram.
48 Fed.Reg. 9764/1 (citations to exhibits omitted). Thus it is apparent that OSHA itself places little confidence in a physician’s ability to identify those workers whose hearing loss is not work related or aggravated by occupational noise exposure.