The Secretary of Labor appeals the judgment of the district court dismissing its petition for a contempt order against Horn Seed Company, Inc. The contempt order was sought for Horn Seed’s failure to com *98 ply with a warrant previously issued by the district court pursuant to the Occupational Safety and Health Act, 29 U.S.C. §§ 651 et seq. We affirm the district court’s dismissal of the Secretary’s petition.
I.
On November 27,1978, Deborah A. Gann, a compliance officer for the Occupational Safety and Health Administration (OSHA), applied to the distriсt court for a warrant to inspect Horn Seed’s premises for possible violations of the Act. The affidavit supporting her application stated:
“On November 7 and November 15, 1978, complaints were received by the Oklahoma City Area Office of OSHA concerning the following hazards which were alleged to exist at the above-described employer’s work place: (1) No respiratory protection is provided for employees working with and around chemicals, insecticides, pesticides, etc.; (2) No safety belts used with ‘Pickers’; (3) No hard hats; (4) Truck drivers operate under influence of drugs; (5) Some trailers have faulty tires; Flammable storage tank (diesel) creates hazard by leakage; Excessive dust in storage areas.
". . .
“Based on the above complaints, I have reason to believe that there may be violations of the Occupational Safety and Health Act which could cause serious bodily injury or death to the employees exposed to the above.”
Rec., vol. I, at 127. On the basis of this application, Senior U.S. District Judge Luther Bohannon concluded there was probable cause for the inspection and issued a search warrant.
The dompliance officer attempted to inspect Horn Seed’s place of business, but the company refused to honor the warrant. The Secretary of Labor obtained an order to show cause why Horn Seed should not be held in civil contempt. Horn Seed responded by moving to quash the warrant. After a hearing, U.S. District Judge Ralph G. Thompson entered an order quashing the warrant and dismissing the civil contempt proceedings. He held “as a matter of law, there was no probable cause demonstrated, sufficient to support the issuance of an inspection warrant.” Rec., vol. I, at 132. His explanation was that “[ujnder any standard of probable cause, in OSHA inspection warrants based on complaint of employees or their representatives, there must be some knowledge of the facts surrounding the receipt of a complaint by the affiant, and a showing of the standing of the comрlainant as an employee or employee representative of respondent employer.” Id. Finding this issue controlling, the district court did not reach other questions raised by Horn Seed concerning the scope of the warrant and the method of its attempted execution.
The Secretary alleges on appeal that the district court erroneously tested the warrant application by a criminal standard of probable cause instead of “the relaxed notions of administrative probаble cause” governing OSHA inspections. Brief for Plaintiff at 14. We agree with the district court that probable cause to issue the warrant was missing, albeit for somewhat different reasons.
II.
Section 8 of the Occupational Safety and Health Act of 1970, 29 U.S.C. § 657, authorizes the Secretary of Labor to enter and inspect work places for occupational hazards. Specifically, section 8(a) provides:
“(a) In order to carry out the purposes of this chapter, the Secretary, upon presenting appropriate credentials to the owner, operator, or agent in charge, is authorized—
(1) to enter without delay and at reasonable times any factory, plant, establishment, construction site, or other area, workplace or environment where work is performed by an employee of an employer; and
(2) to inspect and investigate during regular working hours and at other reasonable times, and within reasonable limits and in a reasonable manner, any such place of employment and all рertinent conditions, structures, ma *99 chines, apparatus, devices, equipment, and materials therein, and to question privately any such employer, owner, operator, agent or employee.”
29 U.S.C. § 657(a). Further authorization is provided in section 8(f):
“(f)(1) Any employees or representative of employees who believe that a violation of a safety or health standard exists that threatens physical harm, or that an imminent danger exists, may request an inspection by giving notice to the Secretary or his authorizеd representative of such violation or danger.... If upon receipt of such notification the Secretary determines there are reasonable grounds to believe that such violation or danger exists, he shall make a special inspection in accordance with the provisions of this section as soon as practicable, to determine if such violation or danger exists.”
Id. § 657(f)(1).
Neither of these sections mentions the need for a warrant to inspect. But in
Marshall v. Barlow’s, Inc.,
Barlow’s
confirmed the holdings of
Camara v. Municipal Court,
“entitlement to inspect will not depend on his demonstrating probable cause to *100 believe that conditions in violation of OSHA exist on the premises. Probable cause in the criminal law sense is not required. For purposes of an administrative search such as this, probable cause justifying the issuance of a warrant may be based not only on specific evidence of an existing violation but also on a showing that ‘reasonable legislative or administrative standards for conducting an . . . inspection are satisfied with respect to a particular [establishment].’ ”
III.
A reasonableness test determines probable cause in an administrative search, for as the Court said in
Camara,
“reasonableness is .. . the ultimate standard.”
In the context of routine, periodic inspections of search sites randomly selected pursuant to a general legislative or administrative plan, the Court has repeatedly held that a showing of reasonableness does not depend upon a demonstration of probable cause that a
particular
dwelling contains violations of the regulatory stаndards being enforced.
See Barlow's,
When a warrant is sought to conduct an inspection according to a general administrative plan, it is reasonable that the magistrate not be concerned with questions of the reliability of evidence and the probability of violation. The reasonable balance between the need to search and the threat of disruption has already been struck by the legislative and administrative guidelines.
See Tyler,
*101 “A warrant showing that a specific business has been chosen for an OSHA search on the basis of a general administrative plan for the enforcement of the Act derived from neutral sources such as, for example, dispersion of employees in various types of industries across a given area, and the desired frequency of searches in any of the lesser divisions of the area would protect an employer’s Fourth Amendment rights.”
Barlow's,
“ ‘safeguarding] the privacy and security of individuals against arbitrary invasions by governmental officials.’ ”
Tyler,
These safeguards are not built in when a search is based on a specific complaint. In such instances, the government is not inspecting on the basis of neutral criteria derived from reasonable legislative or administrative standards. Unless it is possible to infer that the complaint was actually made and that it has some modicum of plausibility to it, the dаnger of arbitrary invasions by governmental officials exists. There are no administrative or legislative guidelines assuring us that the target was not chosen for purposes of harassment. An administrative warrant application based upon specific evidence is more analogous to an application for a criminal search warrant than to an application for a search warrant under a regulatory scheme. Without some sort of scrutiny of the reliability of the “specific evidence” serving as probable cause for an OSHA warrant, no real assessment of the need to search can be made. Absent a true balancing of that need against “the invasion which the search entails,”
Camara,
In
Michigan v. Tyler,
“To secure a warrant to investigate the cause of a fire, аn official must show more than the bare fact that a fire has occurred. The magistrate’s duty is to assure that the proposed search will be reasonable, a determination that requires inquiry into the need for the intrusion on the one hand, and the threat of disruption to the occupant on the other. For routine building inspections, a reasonable balance between these competing concerns is usually achieved by broad legislative or administrative guidelines specifying the purpose, frequency, scope, and manner of conducting the inspections. In the context of investigatory fire searches, which are not programmatic but are responsive to individual events, a more particularized inquiry may be necessary.”
Id.
at 507,
*102 It remains to determine the precise level of scrutiny the Amendment demands when a warrant application is founded on specific evidence of a violation instead of on conformance with a regulatory plan.
IV.
In the criminal setting, probable cause to issue a warrant is found only if the warrant application demonstrates three things. First, it must contain more than mere conclusions that probable cause exists. The magistrate must be “ ‘informed of some of the underlying circumstances’ ” supporting the affiant’s conclusions or those of his informants.
United States v. Ventresca,
As earlier noted,
5
the Supreme Court has indicated that probable cause in the criminal sense is not to be applied to a warrant application based on specific evidence of an OSH A violation. We ourselves have said in a case involving an employee complaint that “the issuance of search warrants in conjunction with administrative proceedings cаnnot be equated with the ‘probable cause’ requirement of the ‘traditional’ Fourth Amendment search in a criminal law setting.”
Marshall v. W & W Steel Co.,
But to say that the same degree of probable cause is not required is not to say that no consideration need be given to the concerns focused on in the criminal setting. Relaxation is not the same as abandonment. When the warrant application is grounded not upon conformance with administrative or legislative guidelines but upon “specific evidence” of violations such as an employee complaint, there must be some plausible basis for believing that a violation is likely to be found. The facts offered must be sufficient to warrant further investigation or testing.
By necessity, such a determination requires the magistrate to consider the reliability of the information tendered in support of the application. Again, a criminal standard is not imposed. Although a “substantial basis” is not required to credit the information’s reliability, there must be some basis for believing that a complaint
*103
was actually made, that the complainant was sincere in his assertion that a violation exists, and that he had some plausible basis for entering a complaint. It is not sufficient that the affiant, as was done in this case, simply state that a complaint was received and detail the conditions alleged to be unsafe. The warrant application must, of course, inform the magistrate of the substance of the complaint so that he can determine whether the alleged conditions, if true, constitute a violation.
See Burkart Randall Division of Textron, Inc. v. Marshall,
“The magistrate had before him the original signed written complaint of Herman Sedillo which stated that ventilation and respiratory protection measures in the tank welding area within W and W’s plant were inadequate. In addition, the magistrate also had the written narrative statement given by Sedillo to OSHA officials, as well as an independent verification of Sedillo’s status as an employee of W and W Steel Company. Finally, the compliance officer of OSHA filed with the magistrate his own affidavit setting forth the steps he had taken in an effort to check and verify the complaint. Such is sufficient in our view to support a finding of probable cause based on ‘specific evidence of an existing violation,’ as mentioned in Barlow’s.”
Ideally, the affidavit should state whether the complaint was received by the affiant personally or by some other specific OSHA official known to the affiant. While the name of the complainant need not be given, the magistrate should be informed as to the source of the complaint. Is the source an employee, a competitor, a customer, a casual visitor to the plant, or someone else? The magistrate should alsо be told whatever underlying facts and surrounding circumstances the complainant provided OSHA. If the complaint was received in written form, it should be attached to the application, although the complainant’s name may be deleted. The affiant should specify the steps he or other OSHA officials took to verify the information in the complaint. The affiant should relate any personal observations he has made of the premises and the employer’s past history of violations. Lastly, as the Supreme Cоurt has said, depending on the circumstances, it may be necessary to provide “the number of prior entries, the scope of the search, the time of day when - it is proposed to be made,” or other relevant factors.
Tyler,
We cannot agree with the Secretary that placing this burden "on OSHA would hamstring its efforts in performing the admittedly vital function of ensuring safety in the work place through prevention and prompt abatement of hazardous conditions. We only require that each warrant application relate what information OSHA has regarding each of these aspects, not that OSHA must always have or have done each of these things. For instance, we are not holding that the affiant must always have personally received the complaint or have personal knowledge of the facts surrounding the making of the complaint. Nor do we require thаt the affiant always have taken steps to verify the complaint. However, the degree of firsthand knowledge possessed by the affiant is certainly relevant to the magistrate’s determination of the complaint’s sincerity and to whether the complaint provides some basis for believing that a violation may exist. A signed, written employee complaint containing detailed information demonstrating first hand knowledge may be so compelling that further verification is unnecessary. On the other hand, more may be demandеd when the complaint is a simple allegation by a competitor or an unknown caller that an OSHA violation exists at a plant.
The approach we outline today has the advantage of leaving some discretion with *104 administrative officials. When the complaint carries its own indicia of sincerity and reliability, OSHA will not be saddled with the burdensome task of undertaking unnecessary corroborative efforts simply to satisfy rigid judicial mandate. But neither will OSHA have the unbridled discretion the Constitution condemns. OSHA’s judgment will be put to the test. Only if the mаgistrate agrees that the complaint appears genuine and provides some basis for believing that a violation may exist on the premises will the warrant issue. Anything less would make administrative probable cause, when based on a specific complaint rather than on conformance with a regulatory plan, not the “relaxed” standard of probable cause the Secretary speaks of, but a nonexistent one. The warrant process would be largely a sham, leaving unguarded the critical Fourth Amendment interests it is meant to protect.
Tested by these standards, the warrant application in this case did not supply probable cause to search. At the contempt proceedings, compliance officer Gann explained the circumstances behind the statements made in her affidavit. She indicated that she had not received the initial telephone complaints, nor was she even sure who had. While she testified that OSHA complaint forms were completed, signed, and returned by the complainants, these were not given to the judge who issued the warrant. Nor was the judge informed that the complainants were employees, or that their status as employees had been verified. The affidavit simply stated that complaints were received and described the conditions alleged to be unsafe and unhealthful. In ruling on the validity of a search warrant, the reviewing court may only consider the information provided the issuing magistrate or judge.
Cf. Spinelli,
Affirmed.
Notes
. The Court said that a warrant is not needed to search “closely regulated” industries, but emphasized that industries such as liquor and firearms represent the “exception” rather than the rule.
Barlow’s,
. Horn Seed argues that the Supreme Court intended the lesser standard of administrative probable cause to apply only to OSHA inspections pursuant to a regulatory plan, with criminal probable cause remaining the test for inspections based on specific evidencе. Whatever doubt remained after
Barlow's
was dispelled by
Michigan v. Tyler,
“In summation, we hold that an entry to fight a fire requires no warrant, and that once in the building, officials may remain there for a reasonable time to investigate the cause of the blaze. Thereafter, additional entries to investigate the cause of the fire must be made pursuant to the warrant procedures governing administrative searches.. . . Evidence of arson discovered in the course of such investigations is admissible at trial, but if the investigating officials find probable сause to believe that arson has occurred and require further access to gather evidence for a possible prosecution, they may obtain a warrant only upon a traditional showing of probable cause applicable to searches for evidence of crime.”
Id.
at 511-12,
. We reject Horn Seed’s contention and the views of the district court that the only complaints the Secretary can act upon are those from employees. In discussing section 8(f)(1), we believe the
Barlow’s
Court meant that employee complaints are an example of what can constitute specific • evidence demonstrating probable cause to search, not that employee complaints are the sole source of satisfactory evidence. See
. Some courts and commentators find it anomalous that when OSHA cites specific evidence of a violation, such as an employee complaint, a more particularized inquiry is needed than when probable cause for the search is grounded upon broad legislative or administrative guidelines drafted to cover a wide variety of cases. See
Burkart Randall,
. See note 2 supra.
