OPINION

GRABER, Circuit Judge:

Plaintiffs Vivid Entertainment, LLC; Califa Productions, Inc.; Kayden Kross; and Logan Pierce are organizations and individuals who make adult films in Los Angeles County. The Los Angeles County Department of Public Health, whose director is a defendant here, sent Plaintiffs a letter stating its intention to enforce the voter-initiated County of Los Angeles Safer Sex in the Adult Film Industry Act (2012) (commonly known as Measure B) (codified at Los Angeles County, Cal., Code tit. 11, div. 1, ch. 11.39, and amending tit. 22, div. 1, ch. 22.56.1925). Measure B imposes a permitting system and additional production obligations on the makers of adult films, including a requirement that performers wear condoms in certain contexts. Plaintiffs sued for declaratory and injunctive relief, arguing that Measure B burdens their freedom of expression in violation of the First Amendment. Defendant Los Angeles County answered that, although it would enforce the ordinance unless ordered by a court not to, it did not intend to defend Measure B because it took a "position of neutrality" with respect to the ordinance's constitutionality. The official proponents of Measure B intervened to defend it.

The district court issued a preliminary injunction forbidding Defendants from enforcing Measure B's fee-setting provision, which gave Defendants discretion to set fees for permits; a provision that allowed warrantless searches by county health officers of any location suspected of producing adult films; and the broad permit modification, suspension, and revocation process. The court denied preliminary injunctive relief, though, for much of the ordinance, including its condom and permitting requirements. Plaintiffs appeal the district court's decision not to enjoin Measure B in full.1 We affirm.

FACTUAL AND PROCEDURAL HISTORY

The citizens of Los Angeles County enacted Measure B in November 2012 by means of the initiative process; it became law on December 14, 2012. The text of the ordinance declared that it was passed in response to documentation by the Los Angeles County Department of Public Health of the widespread transmission of sexually transmitted infections among workers in the adult film industry. Under Measure B, producers of adult films2 must obtain a newly designated "public health permit" before shooting an adult film in Los Angeles County.

Under Measure B as enacted, to obtain such a permit, producers of adult films must pay a fee, provide the Department with proof that certain employees have completed a county-approved training program concerning blood-borne pathogens, display the permit while filming, post a notice at the film site that the use of condoms is required, report to the Department any changes in the permitted business, and comply with all applicable laws, including title 8, section 5193 of the California Code of Regulations. Measure B 11.39.080, .090, .100, .110. Section 5193 mandates barrier protection for all employees who are exposed to blood-borne pathogens, which Measure B interprets to require condoms for performers who engage in vaginal or anal intercourse. Id. 11.39.090. Measure B also provides that a public health permit may be suspended or revoked, and fines or criminal penalties imposed, for failure to comply with all permitting requirements. Id. 11.39.110. A producer who faces modification, suspension, or revocation of a permit may apply for an undefined form of "administrative review." Id. 11.39.110(C).

In addition to providing for monetary and criminal penalties, Measure B allows enforcement of the permitting requirements through a surprise inspection by a Los Angeles County health officer at "any location suspected of conducting any activity regulated by this chapter." Id. 11.39.130. "[F]or purposes of enforcing this chapter," the health officer "may issue notices and impose fines therein and take possession of any sample, photograph, record or other evidence, including any documents bearing upon adult film producer's compliance with the provision of the chapter." Id. Measure B authorizes the district attorney to bring a civil enforcement action for injunctive relief against any producer who fails to cooperate with the health officer. Id. 11.39.140.

On the day that Measure B took effect, Defendant Department of Public Health mailed Plaintiffs a letter notifying them of the new ordinance and stating that it had established provisional permitting fees of $2,000 to $2,500 per year. Plaintiffs then filed this action challenging Measure B as facially unconstitutional under the First Amendment.3 Plaintiffs allege that Measure B's permitting scheme and its condom requirement operate as prior restraints on Plaintiffs' ability to create expression, in the form of adult films, which is protected by the First Amendment.

Over Plaintiffs' objection, the district court allowed supporters of Measure B to intervene. Following the Supreme Court's decision in Hollingsworth v. Perry, ___ U.S. ___, 133 S.Ct. 2652, 186 L.Ed.2d 768 (2013), Plaintiffs asked the court to reconsider because, they argued, Intervenors lacked Article III standing. The district court denied the motion to reconsider.

The district court granted in part and denied in part Intervenors' motion to dismiss, and granted in part and denied in part Plaintiffs' request for a preliminary injunction. In granting preliminary injunctive relief, the district court severed one chapter of Measure B in its entirety and severed portions of three other chapters. Appendix A contains Measure B and shows the parts that the district court enjoined and severed.

Plaintiffs timely appeal the denial of complete preliminary injunctive relief.4 They argue that the enjoined provisions are not properly severable, so the likely invalidity of some parts of the ordinance requires enjoining the entire ordinance. In the alternative, Plaintiffs argue that the district court erred in denying preliminary injunctive relief with respect to Measure B's requirements that producers: (1) acquire a permit before beginning production on an adult film; (2) demonstrate that employees have completed a county-approved training program concerning blood-borne pathogens as a condition precedent to issuance of the permit; and (3) require performers to use condoms "during any acts of vaginal or anal sexual intercourse."

STANDARD OF REVIEW

We review for abuse of discretion denial of a preliminary injunction. Alliance for the Wild Rockies v. Cottrell, 632 F.3d 1127, 1131 (9th Cir.2011). "As long as the district court got the law right, it will not be reversed simply because we would have arrived at a different result if we had applied the law to the facts of the case." A & M Records, Inc. v. Napster, Inc., 284 F.3d 1091, 1096 (9th Cir.2002) (internal quotation marks and brackets omitted). A district court abuses its discretion, however, if it applies an incorrect legal standard. Does 1-5 v. Chandler, 83 F.3d 1150, 1152 (9th Cir.1996). Accordingly, we review de novo the "legal premises underlying a preliminary injunction." A & M Records, 284 F.3d at 1096.

DISCUSSION

A. Jurisdiction

Citing Perry, Plaintiffs argue that we lack jurisdiction over this appeal, because Intervenors lack Article III standing. We disagree with their reading of Perry and with their contention that Intervenors must have standing for this appeal to proceed.

The Supreme Court has held that a party must have Article III standing both to initiate an action and to seek review on appeal. Arizonans for Official English v. Arizona, 520 U.S. 43, 64, 117 S.Ct. 1055, 137 L.Ed.2d 170 (1997). But an intervenor who performs neither of those functions and no other function that invokes the power of the federal courts need not meet Article III standing requirements. Yniguez v. Arizona, 939 F.2d 727, 731 (9th Cir.1991), vacated by Arizonans for Official English, 520 U.S. at 80, 117 S.Ct. 1055, as recognized in League of United Latin Am. Citizens v. Wilson, 131 F.3d 1297, 1305 n. 5 (9th Cir.1997); see also Perry, 133 S.Ct. at 2661 (citing Art. III, § 2) (holding that "any person invoking the power of a federal court must demonstrate standing to do so" (emphasis added)). Nothing in Perry, which concerned the question whether an intervenor who sought to appeal had Article III standing, affects that conclusion. Plaintiffs have standing, and it is they alone who have invoked the federal courts' jurisdiction. For that reason, we need not and do not decide whether Intervenors satisfy the requirements of Article III standing.

To the extent that Plaintiffs contend that the district court erred in granting intervention, we cannot consider their challenge. An order allowing intervention under Federal Rule of Civil Procedure 24(a) is not a final order and is not an interlocutory order appealable by statute, so an appeal on that issue is premature until entry of final judgment. Alsea Valley Alliance v. Dep't of Commerce, 358 F.3d 1181, 1187 (9th Cir.2004).

B. Severability

Plaintiffs next urge that, having held that they are likely to succeed on the merits with respect to some provisions of Measure B, the district court had to enjoin operation of the entire ordinance whether or not the remainder independently satisfies the standards for injunctive relief. For the reasons that follow, we disagree.

Federal courts should avoid "judicial legislation" — that is, amending, rather than construing, statutory text — out of respect for the separation-of-powers principle that only legislatures ought to make positive law. United States v. Nat'l Treasury Emps. Union, 513 U.S. 454, 479, 115 S.Ct. 1003, 130 L.Ed.2d 964 (1995). But, because of countervailing separation-of-powers principles, courts must respect the laws made by legislatures and, therefore, should avoid nullifying an entire statute when only a portion is invalid. Brockett v. Spokane Arcades, Inc., 472 U.S. 491, 502, 105 S.Ct. 2794, 86 L.Ed.2d 394 (1985). These concerns have led to the judicial doctrine of severability, that is, the "elementary principle that the same statute may be in part constitutional and in part unconstitutional, and that if the parts are wholly independent of each other, that which is constitutional may stand while that which is unconstitutional will be rejected." Id. (internal quotation marks omitted). The need for deference and restraint in severing a state or local enactment is all the more acute because of our respect for federalism and local control. See City of Lakewood v. Plain Dealer Publ'g Co., 486 U.S. 750, 772, 108 S.Ct. 2138, 100 L.Ed.2d 771 (1988).

Because a court may not use severability as a fig leaf for judicial legislation, courts have fashioned limits on when a statute may be severed. See Yu Cong Eng v. Trinidad, 271 U.S. 500, 518, 46 S.Ct. 619, 70 L.Ed. 1059 (1926) ("[I]t is very clear that amendment may not be substituted for construction, and that a court may not exercise legislative functions to save the law from conflict with constitutional limitation."). In keeping with federalism principles, the "[s]everability of a local ordinance is a question of state law." City of Lakewood, 486 U.S. at 772, 108 S.Ct. 2138.

California law directs courts to consider first the inclusion of a severability clause in the legislation. Cal. Redev. Ass'n v. Matosantos, 53 Cal.4th 231, 135 Cal.Rptr.3d 683, 267 P.3d 580, 607 (2011). "The presence of such a clause establishes a presumption in favor of severance." Id. "Although not conclusive, a severability clause normally calls for sustaining the valid part of the enactment...." Santa Barbara Sch. Dist. v. Superior Court, 13 Cal.3d 315, 118 Cal.Rptr. 637, 530 P.2d 605, 618 (1975) (internal quotation marks omitted).

Measure B contains this severability clause:

Measure B § 8. Section 8 states clearly that the people, acting in their legislative capacity, intended any provision and any part of a provision, if invalid or unconstitutional, to be severed from the ordinance. The district court thus properly held that Measure B's severability clause establishes a presumption of severability.

Next, California law directs courts to "consider three additional criteria: The invalid provision must be grammatically, functionally, and volitionally separable." Cal. Redev. Ass'n, 267 P.3d at 607 (internal quotation marks and brackets omitted). We will consider each criterion in turn.

"Grammatical separability, also known as mechanical separability, depends on whether the invalid parts can be removed as a whole without affecting the wording or coherence of what remains." Id. (internal quotation marks omitted). "[T]he `grammatical' component of the test for severance is met by the severability clause considered in conjunction with the separate and discrete provisions of [the statute]." Barlow v. Davis, 72 Cal.App.4th 1258, 85 Cal.Rptr.2d 752, 757 (1999). "To be grammatically separable, the valid and invalid parts of the statute can be separated by paragraph, sentence, clause, phrase, or even single words." People v. Nguyen, 222 Cal.App.4th 1168, 166 Cal.Rptr.3d 590, 609 (2014) (internal quotation marks omitted). "[Where] the defect cannot be cured by excising any word or group of words, the problem is quite different and more difficult of solution." Ex parte Blaney, 30 Cal.2d 643, 184 P.2d 892, 900 (1947); Santa Barbara Sch. Dist., 530 P.2d at 617.

Here, Plaintiffs contend that the district court abused its from the definition of an adult film. Specifically, the district court struck part of 11.39.010 of Measure B as follows:

In large part, as can be seen, the district court severed distinct clauses. The district court also severed some individual words but, grammatically, they are understood by the reader to include complete clauses. For example, the compound clause "engage in oral, vaginal, or anal penetration" means — and easily could have been drafted to say — "engage in oral penetration, engage in vaginal penetration, or engage in anal penetration." For that reason, the district court did, in fact, sever only distinct provisions from Measure B, and that severance did not alter the meaning of the remaining text in any way. California courts have long held that parts of a compound clause are grammatically severable from a statute if their omission would not affect the meaning of the remaining text. Ex parte Blaney, 184 P.2d at 900; Santa Barbara Sch. Dist., 530 P.2d at 617; see also Legislature v. Eu, 54 Cal.3d 492, 286 Cal.Rptr. 283, 816 P.2d 1309, 1335-36 (1991) (holding as grammatically severable "or serving in" from "elected to or serving in the Legislature on or after November 1, 1990"); Borikas v. Alameda Unified Sch. Dist., 214 Cal.App.4th 135, 154 Cal.Rptr.3d 186, 212 (2013) (holding as grammatically severable "residential" from "[o]n each taxable, residential parcel at the rate of $120 per year"); City of Dublin v. County of Alameda, 14 Cal.App.4th 264, 17 Cal.Rptr.2d 845, 850-51 (1993) (holding as grammatically severable "incorporated and" from "the geographic entity, including both the incorporated and unincorporated areas"). In short, the district court permissibly held that the disputed portions of Measure B are grammatically severable.5

Our next consideration, functional severability, "depends on whether the remainder [of the statute] is complete in itself." Santa Barbara Sch. Dist., 530 P.2d at 618 (internal quotation marks omitted). To be functionally severable, "[t]he remaining provisions must stand on their own, unaided by the invalid provisions nor rendered vague by their absence nor inextricably connected to them by policy considerations. They must be capable of separate enforcement." People's Advocate, Inc. v. Superior Court, 181 Cal.App.3d 316, 226 Cal.Rptr. 640, 649 (1986). Here, the district court enjoined the provisions of Measure B that allowed for modification, suspension, and revocation of permits; that authorized administrative searches; and that allowed discretion in setting fees. The rest of the ordinance remains intact: the permitting scheme, with its condom and educational requirements; and enforcement through fines and criminal charges. In addition, as the district court noted, even in the absence of the administrative search provision, Defendants can obtain a warrant to enforce Measure B. Because the remaining parts of Measure B operate independently, are not rendered vague in the absence of the invalid provisions, and are capable of separate enforcement, the district court permissibly ruled that the provisions are functionally severable.

Our final consideration, volitional severability, "depends on whether the remainder [of the statute] is complete in itself and would have been adopted by the legislative body had [it] foreseen the partial invalidation of the statute." Santa Barbara Sch. Dist., 530 P.2d at 618 (internal quotation marks omitted). With respect to ballot initiatives, the test for volitional severability "is whether it can be said with confidence that the electorate's attention was sufficiently focused upon the parts to be severed so that it would have separately considered and adopted them in the absence of the invalid portions." Gerken v. Fair Political Practices Comm'n, 6 Cal.4th 707, 25 Cal.Rptr.2d 449, 863 P.2d 694, 699 (1993) (internal quotation marks and emphasis omitted).

The district court preserved the requirements that producers of adult films in Los Angeles County obtain permits, train employees about the sexual transmission of disease, and require performers to wear condoms when engaged in vaginal or anal intercourse. The district court also preserved the enforcement mechanisms of fines and criminal penalties. As the court correctly noted, the "Findings and Declaration" section of the initiative emphasizes (1) a growing public concern over the spread of HIV/AIDS and other sexually transmitted infections in the adult film industry; (2) the importance of safe sex practices, and the use of condoms in particular, in limiting the spread of HIV/AIDS and other sexually transmitted infections; and (3) a failure to enforce current state laws mandating the use of condoms by performers in adult films. Measure B § 2. Thus, the Declaration demonstrates that the public's attention was focused primarily on heightening enforcement of the condom requirement. That is, even in the absence of the severed segments, the remaining provisions centrally address the voters' stated concerns. The district court permissibly concluded that the condom and permitting requirements are volitionally severable from the fee-setting, inspections, and administrative procedures.

Plaintiffs counter that the fee provisions are not volitionally severable, because the voters would not have passed Measure B as an "unfunded mandate." But the Declaration contained in Measure B says nothing about money or revenue neutrality. Rather, the text demonstrates that the core purpose of the initiative "was presented to the electorate as a distinct aim, separate and apart from the measure's funding mandate." McMahan v. City of San Francisco, 127 Cal.App.4th 1368, 26 Cal.Rptr.3d 509, 513 (2005) (holding that a funding provision was volitionally severable from the primary regulatory scheme).

In sum, the district court did not abuse its discretion in granting preliminary injunctive relief with respect to only certain parts of Measure B, while allowing enforcement of other provisions as severable. We now turn to Plaintiffs' assertion that, even if severance is permissible, the district court erred in denying preliminary injunctive relief with respect to additional parts of the ordinance: the condom mandate and the permitting requirement.

C. Denial of Preliminary Injunctive Relief

In deciding whether a preliminary injunction should issue, a district court must consider four factors: (1) whether the plaintiff has shown a likelihood of success on the merits; (2) whether the plaintiff has shown a likelihood of irreparable harm in the absence of preliminary relief; (3) whether the balance of equities tips in the plaintiff's favor; and (4) whether preliminary relief is in the public interest. Winter v. Natural Res. Def. Council, Inc., 555 U.S. 7, 20, 129 S.Ct. 365, 172 L.Ed.2d 249 (2008).

Thalheimer v. City of San Diego, 645 F.3d 1109, 1115-16 (9th Cir.2011). But even if the plaintiff demonstrates likely success on the merits, the plaintiff still must demonstrate irreparable injury, a favorable balance of equities, and the tipping of the public interest in favor of an injunction. Id. at 1128. That is, although

DISH Network Corp. v. FCC, 653 F.3d 771, 776 (9th Cir.2011).

1. Condom Mandate

The district court held that Plaintiffs are unlikely to succeed on the merits of their First Amendment challenge to the condom requirement. The court did not abuse its discretion in declining to enjoin the enforcement of the condom mandate. The condom mandate survives intermediate scrutiny because it has only a de minimis effect on expression, is narrowly tailored to achieve the substantial governmental interest of reducing the rate of sexually transmitted infections, and leaves open adequate alternative means of expression.

As a threshold matter, Plaintiffs argue that the district court applied the wrong standard — intermediate scrutiny — and that the condom mandate should be subject to strict scrutiny. We disagree.

The Supreme Court has recognized that nearly all regulation of the adult entertainment industry is content based. See City of Los Angeles v. Alameda Books, Inc., 535 U.S. 425, 448, 122 S.Ct. 1728, 152 L.Ed.2d 670 (2002) (Kennedy, J., concurring in the judgment). Content-based regulation of speech generally receives strict scrutiny, but we have fashioned an exception, grounded in Alameda Books, that applies intermediate scrutiny if two conditions are met. Ctr. For Fair Pub. Policy v. Maricopa County, 336 F.3d 1153, 1161, 1164-65 (9th Cir.2003) (citing Alameda Books, 535 U.S. at 434, 122 S.Ct. 1728) (recognizing Justice Kennedy's concurrence as controlling). First, the ordinance must regulate "speech that is sexual or pornographic in nature." Gammoh v. City of La Habra, 395 F.3d 1114, 1123, amended on denial of reh'g, 402 F.3d 875 (9th Cir.2005). Second, "the primary motivation behind the regulation [must be] to prevent secondary effects." Id. But even if those two conditions are met, strict scrutiny may still apply if the regulation amounts to a complete ban on expression. Dream Palace v. County of Maricopa, 384 F.3d 990, 1021 (9th Cir.2004).

We assume, but need not and do not decide, that Measure B's condom mandate is a content-based regulation of speech. Nonetheless, Measure B regulates sexual speech in order to prevent the secondary effects of sexually transmitted infections, thus falling within the Alameda Books exception. Plaintiffs argue that, despite that exception, the district court should have applied strict scrutiny because the condom mandate amounts to a complete ban on their protected expression.

As an initial matter, Plaintiffs' argument presupposes that their relevant expression for First Amendment purposes is the depiction of condomless sex. But "simply to define what is being banned as the `message' is to assume the conclusion." City of Erie v. Pap's A.M., 529 U.S. 277, 293, 120 S.Ct. 1382, 146 L.Ed.2d 265 (2000). In Pap's A.M., a plurality of the Supreme Court concluded that a general ban on public nudity, which required erotic dancers to wear at least pasties and a G-string while dancing, did not violate the First Amendment. Id. at 302, 120 S.Ct. 1382. In reaching that conclusion, the opinion rejected the argument that the pastiesand-G-string requirement functioned as a complete ban on the dancers' expression of "nude dancing." Id. at 292-93, 120 S.Ct. 1382. Instead, the opinion defined the relevant expression more broadly as "the dancer's erotic message." Id. at 301, 120 S.Ct. 1382. We undertook a similar analysis, albeit without reference to Pap's A.M., in Gammoh, in which we upheld an ordinance that required dancers to stay at least two feet away from patrons during their performances. 395 F.3d at 1123. The plaintiffs there argued that the ordinance completely banned their expression, which they defined as "proximate dancing." Id. In response, we stressed that "the `expression' at issue could always be defined to include the contested restriction," but "virtually no ordinance would survive this analysis." Id. We instead defined the relevant expression as "the dancer's erotic message" and upheld the ordinance. Id. at 1128.

In light of those cases, we must examine more carefully whether Plaintiffs' relevant expression is the depiction of condomless sex. Plaintiffs submitted declarations stating that condomless sex differs from sex generally because condoms remind the audience about real-world concerns such as pregnancy and disease. Under this view, films depicting condomless sex convey a particular message about sex in a world without those risks. The Supreme Court has cautioned, however, that "`[i]t is possible to find some kernel of expression in almost every activity a person undertakes-for example, walking down the street or meeting one's friends at a shopping mall-but such a kernel is not sufficient to bring the activity within the protection of the First Amendment.'" Barnes v. Glen Theatre, Inc., 501 U.S. 560, 570, 111 S.Ct. 2456, 115 L.Ed.2d 504 (1991) (quoting City of Dallas v. Stanglin, 490 U.S. 19, 25, 109 S.Ct. 1591, 104 L.Ed.2d 18 (1989)).

To determine whether conduct is protected by the First Amendment, we ask not only whether someone intended to convey a particular message through that conduct, but also whether there is a "great" likelihood "that the message would be understood by those who viewed it." Spence v. Washington, 418 U.S. 405, 410-11, 94 S.Ct. 2727, 41 L.Ed.2d 842 (1974) (per curiam). Here, we agree with the district court that, whatever unique message Plaintiffs might intend to convey by depicting condomless sex, it is unlikely that viewers of adult films will understand that message. So condomless sex is not the relevant expression for First Amendment purposes;6 instead, the relevant expression is more generally the adult films' erotic message. See Pap's A.M., 529 U.S. at 293, 120 S.Ct. 1382; Gammoh, 395 F.3d at 1123.

With Plaintiffs' expression so defined, we conclude that strict scrutiny is inappropriate because the condom mandate does not ban the relevant expression completely. Rather, it imposes a de minimis restriction. In Pap's A.M., the Supreme Court held that the pasties-and-G-string requirement did not violate the First Amendment because, even if the ban "has some minimal effect on the erotic message by muting that portion of the expression that occurs when the last stitch is dropped," that effect was de minimis. 529 U.S. at 294, 120 S.Ct. 1382 (emphasis added). That was so even though the ban "certainly ha[d] the effect of limiting one particular means of expressing the kind of erotic message being disseminated." Id. at 292-93, 120 S.Ct. 1382; see also Barnes, 501 U.S. at 571, 111 S.Ct. 2456 (noting that a requirement that erotic dancers wear pasties and G-strings "does not deprive the dance of whatever erotic message it conveys; it simply makes the message slightly less graphic").

Many of our sister circuits have relied on Pap's A.M. in upholding de minimis restrictions on speech using intermediate scrutiny. See, e.g., Sensations, Inc. v. City of Grand Rapids, 526 F.3d 291, 299 (6th Cir.2008) (upholding a nudity ban under intermediate scrutiny because Pap's A.M. and Barnes had characterized a similar regulation as de minimis); Fantasy Ranch Inc. v. City of Arlington, 459 F.3d 546, 562 (5th Cir.2006) (rejecting an argument that an ordinance requiring a certain distance between dancers and the audience enacted a "complete ban on proximate nude dancing"); Heideman v. S. Salt Lake City, 348 F.3d 1182, 1195-96 (10th Cir.2003) (applying Pap's A.M. to conclude that a ban on nude erotic dancing was not a "total ban" on speech). And, as noted, we followed this same analytical approach in Gammoh, 395 F.3d at 1122-23.

A similar analysis applies to the condom mandate. The requirement that actors in adult films wear condoms while engaging in sexual intercourse might have "some minimal effect" on a film's erotic message, but that effect is certainly no greater than the effect of pasties and G-strings on the erotic message of nude dancing. In light of Pap's A.M. and the other precedent cited above, we conclude that the restriction on expression in this case is de minimis. And a de minimis restriction on expression is, by definition, not a complete ban on expression, and so does not trigger strict scrutiny. Accordingly, the mandate is subject to intermediate scrutiny.

The district court properly exercised its discretion in concluding that the condom requirement likely would survive intermediate scrutiny. "A statute will survive intermediate scrutiny if it: (1) is designed to serve a substantial government interest; (2) is narrowly tailored to serve that interest; and (3) does not unreasonably limit alternative avenues of communication." Gammoh, 395 F.3d at 1125-26, as amended on denial of reh'g, 402 F.3d at 875, 876.

The purpose of Measure B is twofold: (1) to decrease the spread of sexually transmitted infections among performers within the adult film industry, (2) thereby stemming the transmission of sexually transmitted infections to the general population among whom the performers dwell. Plaintiffs do not contest that the government has a substantial interest in preventing certain secondary effects of the adult film industry, including the spread of sexually transmitted infections. See Rubin v. Coors Brewing Co., 514 U.S. 476, 485, 115 S.Ct. 1585, 131 L.Ed.2d 532 (1995) (stating that "the Government ... has a significant interest in protecting the health, safety, and welfare of its citizens"); Ctr. For Fair Pub. Policy, 336 F.3d at 1166 ("It is beyond peradventure at this point in the development of the doctrine that a state's interest in curbing the secondary effects associated with adult entertainment establishments is substantial."). Rather, Plaintiffs contend that Measure B's condom mandate is not narrowly tailored to serve the government's interest.

In order to be narrowly tailored for purposes of intermediate scrutiny, the regulation "`need not be the least restrictive or the least intrusive means' available to achieve the government's legitimate interests." Berger v. City of Seattle, 569 F.3d 1029, 1041 (9th Cir.2009) (en banc) (quoting Ward v. Rock Against Racism, 491 U.S. 781, 798, 109 S.Ct. 2746, 105 L.Ed.2d 661 (1989)). "Rather, the requirement of narrow tailoring is satisfied so long as the regulation promotes a substantial government interest that would be achieved less effectively absent the regulation." Colacurcio v. City of Kent, 163 F.3d 545, 553 (9th Cir.1998) (internal quotation marks and ellipsis omitted). This is not to say that narrow tailoring allows a regulation to burden more speech than is necessary to satisfy the interest, but we may not invalidate such a regulation "simply because there is some imaginable alternative that might be less burdensome on speech." United States v. Albertini, 472 U.S. 675, 689, 105 S.Ct. 2897, 86 L.Ed.2d 536 (1985).

Plaintiffs' narrow-tailoring argument rests largely on the proposition that Measure B duplicates a voluntary testing and monitoring scheme that already is in place in the industry. The adult film industry and its trade associations have established the Adult Protection Health & Safety Service, which has implemented a program whereby performers are tested, either monthly or more frequently, and the test results are made available in a database. In addition, if the Safety Service receives notification of a positive test result, it must inform the Department of Public Health. Adult film producers and performers have access to the database in order to verify that performers have been tested and that those tests have been negative. Certain employers require their performers, by contract, to submit to testing at various intervals. For example, Plaintiff Kross' contract requires testing every 15 days, Plaintiff Pierce is tested every 14 days, and all of Plaintiff Vivid Entertainment's performers are tested at least once every 28 days.

On the day of production, Plaintiff Vivid Entertainment requires each performer to provide identification, and each performer's test history is drawn from the Safety Service database. Plaintiff Vivid Entertainment allows participation in the production only by performers with a current test status and a negative result. Plaintiffs Kross and Pierce declare that they undertake this screening process before every explicit scene in which they perform, and both Plaintiffs Kross and Pierce declare that they would not take part in an explicit scene if the screening measures were not in place. Plaintiffs also provided testimony from industry officials that this testing system is effective.

The district court considered Plaintiffs' evidence and weighed it against contradictory evidence that the industry's testing scheme is ineffective. In particular, the district court considered a 2009 letter from the County of Los Angeles Department of Public Health to support the conclusion that Measure B, passed in 2012, was designed to address the spread of disease and is narrowly tailored to that end.7 The Findings and Declaration section of Measure B refers specifically to documentation by the Los Angeles County Department of Public Health of the spread of HIV/AIDS and other sexually transmitted infections in the adult film industry. Measure B § 2.

In the 2009 letter, the Department of Public Health reported that its analysis of 2008 data showed a markedly higher rate of sexually transmitted infections for performers within the adult film industry, 20%, than for the general public, 2.4%, and even for the county area with the highest rate of infection, 4.5%. The Department of Public Health also found that 20.2% of performers in adult films diagnosed with an infection were reinfected within one year. Further, the Department of Public Health opined that the data with respect to infection rates were likely underestimated, because rectal and oral screenings were not completed with regularity among workers in the industry.

The district court weighed all the evidence before it and, finding the 2009 letter especially compelling, held that Plaintiffs were unlikely to succeed on the merits in their First Amendment challenge to the condom mandate. In so doing, the district court did not abuse its discretion.8

On appeal, Plaintiffs also argue that Measure B's condom mandate is not narrowly tailored, and is largely ineffective, because makers of adult films can produce films across county lines without having performers wear condoms. As an initial matter, it bears noting that Plaintiffs offered evidence before the district court that Measure B has drastically reduced the number of adult films produced by the industry because the productions, which depend heavily on the "regular" film industry's infrastructure in Los Angeles County, cannot be moved elsewhere. That evidence undermines Plaintiffs' new contention that Measure B is ineffective because of the adult film industry's ready mobility.

But, more importantly, Plaintiffs' argument overstates the standard for narrow tailoring, which simply requires that the regulation "promote[] a substantial government interest that would be achieved less effectively absent the regulation." Colacurcio, 163 F.3d at 553. The regulation need not be the most effective way to achieve the government's substantial interest, nor must it be shown that the regulation cannot be circumvented. Rather, it suffices if the regulation helps to achieve the substantial government interest effectively. Id.

Finally, Plaintiffs contend that Measure B's condom mandate unconstitutionally forecloses alternative channels of communication. As we noted in Gammoh, "[t]his inquiry is analogous" to our analysis of whether the condom mandate is a complete ban on expression. 395 F.3d at 1128. In Gammoh, we held that the required two-foot separation between dancers and patrons left open alternative channels of communication because the requirement "slightly impaired [the message]," but "the dancer's erotic message [could] still be communicated from a slight distance." Id. The same is true here. Measure B is a minimal restriction on Plaintiffs' expression that "leaves ample capacity to convey [Plaintiffs'] erotic message." Pap's A.M., 529 U.S. at 301, 120 S.Ct. 1382. Accordingly, the district court did not abuse its discretion in holding that the condom requirement leaves alternative channels of expression available.

2. Permitting System

The portions of Measure B's permitting system left in place by the district court also survive constitutional scrutiny.9 Plaintiffs first argue that the remaining permitting requirements are impermissibly content based and therefore unconstitutional. But a licensing scheme that regulates adult entertainment is not unconstitutional simply because it is content based. See Dream Palace, 384 F.3d at 1001. Plaintiffs also argue "that the remnants of Measure B's permitting regime left intact are [not] narrowly tailored." See Forsyth County v. Nationalist Movement, 505 U.S. 123, 130, 112 S.Ct. 2395, 120 L.Ed.2d 101 (1992) (holding that "any permit scheme... must be narrowly tailored"). As discussed above, narrow tailoring requires only that the remaining portions of the permitting scheme "promote[] a substantial government interest that would be achieved less effectively absent the regulation." Colacurcio, 163 F.3d at 553 (internal quotation marks omitted). The permitting system's requirements that adult film producers complete training about blood-borne pathogens and post a permit during shooting still serve the County's interest in preventing sexually transmitted infections. That remains so even in light of the other portions of the permitting system that the district court enjoined. Finally, Plaintiffs argue that the permitting scheme grants county officials too much discretion, but the district court correctly concluded that the remaining permitting provisions leave little, if any, discretion to government officials. Accordingly, the district court did not abuse its discretion in denying preliminary injunctive relief with respect to Measure B's remaining permitting requirements.

CONCLUSION

We have jurisdiction over this appeal whether or not Intervenors have demonstrated Article III standing. The district court did not abuse its discretion in holding that the invalid portions of Measure B are severable. Nor did the district court abuse its discretion in denying a preliminary injunction with respect to the condom and permitting provisions of Measure B.

AFFIRMED.

APPENDIX A

The district court did not provide a line-edited version of its severance analysis. For purposes of clarity, we provide the attached interpretation of the district court's analysis.