Cosmetic Preservatives: FDA Rules and MoCRA Requirements

The FDA’s rules on cosmetic preservatives sit inside the Federal Food, Drug, and Cosmetic Act and, since December 2022, the Modernization of Cosmetics Regulation Act (MoCRA). Preservatives do not need FDA approval before a product goes on sale, but the agency bans specific ingredients outright, requires manufacturers to have evidence that their products are safe, sets labeling standards that apply to every preservative on the ingredient list, and now has power to order recalls and demand reports of serious adverse reactions. The regulatory weight falls on the manufacturer; the FDA polices the result.

No Pre-Market Approval, But Real Legal Duties

Cosmetics are not drugs. A company can formulate a lotion, shampoo, or cream with any preservative it chooses and place it on the market without the FDA reviewing or certifying the ingredient. The only cosmetic ingredients that require specific FDA listing before use are color additives.¹

That freedom comes with liability. A cosmetic that is unsafe when used as directed is “adulterated” under 21 U.S.C. § 361, and one whose label is false, misleading, or missing required information is “misbranded” under 21 U.S.C. § 362.²³ Introducing either into interstate commerce is a prohibited act under 21 U.S.C. § 331.⁴ The FDA enforces after the fact, but the standard the company had to meet was in place from the moment the product shipped.

Preservatives the FDA Has Banned or Restricted

The FDA has used its authority under 21 CFR Part 700, Subpart B, to prohibit or restrict several substances that were once used as preservatives or antimicrobial agents in cosmetics.⁵

Mercury compounds are banned in cosmetics, with one narrow exception: they may be used as preservatives in eye-area cosmetics at no more than 65 parts per million, and only when no safe and effective alternative exists. Mercury compounds are exceptionally effective against Pseudomonas bacteria, which can cause serious eye infections including blindness, which is why the carve-out exists.⁶
Halogenated salicylanilides, including tribromsalan and dibromsalan, are prohibited at any concentration. They were previously used in soaps and skin products.
Bithionol, formerly used as an antibacterial agent in detergent bars, shampoos, creams, and lotions, is banned as a deleterious substance.

Other banned cosmetic ingredients, including chloroform, methylene chloride, vinyl chloride, and certain zirconium compounds in aerosol products, are not all preservatives but confirm that the FDA does remove dangerous ingredients from the market even without a pre-market review system.

Safety Substantiation and Challenge Testing

MoCRA codified what the industry already treated as a duty. A manufacturer must have “adequate substantiation of safety” for each cosmetic product and its ingredients: tests, studies, research, analyses, or other evidence that qualified scientific experts would consider sufficient to support a reasonable certainty of safety.⁷ A product without adequate substantiation is treated as adulterated.

Because the FDA does not run its own ingredient reviews, much of the substantiation record for common preservatives comes from the Cosmetic Ingredient Review, an independent scientific panel that evaluates published research on individual ingredients. CIR findings do not carry the force of law, but the FDA references them regularly and they function as the industry’s default safety authority.

Where the FDA has reason to believe a product is likely adulterated in a way that threatens serious health consequences or death, the agency can access the company’s records, including manufacturing records, analytical results, complaint records, and the safety substantiation file itself.⁸ Adverse event records must be retained for six years, or three years for qualifying small businesses.

Preservative Challenge Testing

Proving that a single ingredient is safe is not the same as proving that a finished product resists contamination. The standard method for the second question is the USP Chapter 51 Antimicrobial Effectiveness Test, often called a preservative challenge test. The product is deliberately inoculated with standardized doses of five organisms, including E. coli, Staph aureus, Pseudomonas, Candida albicans, and Aspergillus niger, and the preservative system has to knock the counts down on schedule.

For topical products such as lotions and creams (Category 2 in the USP framework), the preservative must achieve at least a 2.0 log reduction in bacteria within 14 days with no increase through day 28. Yeast and mold counts must not increase across the full testing period. Slowing microbial growth is not enough; the system has to actively reduce contamination the consumer introduces after opening the container.

Labeling Rules That Apply to Preservatives

The Fair Packaging and Labeling Act requires every retail cosmetic to carry an accurate ingredient declaration, and 21 CFR Part 701 sets out how it must be written.⁹ Ingredients appear under standardized names drawn from a hierarchy that begins with names established by the FDA Commissioner and then the dictionary published by the Personal Care Products Council, followed by the U.S. Pharmacopeia and other compendia. The industry-standard names from that dictionary are widely known as INCI names, which is why the label reads “Phenoxyethanol” rather than a trade name.

Order on the label follows concentration. Ingredients above one percent of the formula must be listed in descending order of predominance; ingredients at one percent or below can appear in any order after them.¹⁰ Preservatives are used in small amounts and almost always sit near the end of the list. If you are scanning for a specific one, read from the bottom up.

Products intended solely for licensed professionals can be exempt from the ingredient declaration, but only if they are not also sold to consumers for home use.¹¹ A product that fails the labeling standards is misbranded.

What Changed Under MoCRA

MoCRA, signed into law in December 2022, is the largest update to federal cosmetic regulation in decades. It filled several gaps that the FDA had lived with for years.

Facility Registration and Product Listing

Manufacturers and processors must register their facilities with the FDA and renew every two years. The “responsible person” named on the label must list each marketed product, including its ingredients, and update the listing annually.¹² Before MoCRA, the FDA had no systematic way to know what products were on the market or where they were made.

Good Manufacturing Practices

MoCRA directs the FDA to establish good manufacturing practice requirements for cosmetic facilities.¹³ For preservation, contamination during manufacturing can defeat even a well-designed preservative system, so GMPs matter directly. The FDA has issued draft guidance; final rules are still in development.

Mandatory Adverse Event Reporting

Responsible persons must report serious adverse events to the FDA within 15 business days of learning about them.¹⁴ A serious adverse event includes death, a life-threatening experience, hospitalization, persistent disability, a birth defect, an infection, or significant disfigurement such as serious rashes, second- or third-degree burns, or significant hair loss, along with any reaction that requires medical or surgical intervention to prevent one of those outcomes.¹³ New medical information that surfaces within a year of the initial report triggers another 15-business-day deadline for an update.

Preservative-related complaints are exactly where this new pipeline shows its value. Allergic contact dermatitis and chemical sensitivity are among the most common reactions to cosmetic ingredients, and preservatives like methylisothiazolinone have been linked to sensitization at certain concentrations. Reports that previously stayed inside company files now reach the FDA on a defined schedule.

Mandatory Recall Authority

Before MoCRA the FDA could ask for a voluntary recall and, if refused, go to court for an injunction or product seizure. MoCRA added the power to order a mandatory recall when there is a reasonable probability that a cosmetic is adulterated or misbranded and use could cause serious health consequences or death, provided the company has first been given a chance to act voluntarily and has refused.¹⁵

How the FDA Enforces the Rules

Enforcement escalates in steps. Warning letters are the most common opening move, putting the company on notice of an identified violation. If that does not resolve the problem, the FDA can seek a federal court injunction to stop manufacture or distribution, or arrange for U.S. Marshals to seize products the agency considers adulterated or misbranded. Mandatory recall sits on top of those options for products that pose a reasonable probability of serious health consequences and where the company has refused to act.¹⁵ Violations of § 331 can also trigger criminal penalties under 21 U.S.C. § 333, including fines and imprisonment.

In practice, most cosmetic enforcement runs through warning letters and voluntary compliance. Seizures and prosecutions are rare, and typically involve acute contamination rather than routine preservative disputes. What MoCRA changed is the toolkit behind the letter: registration data, adverse event reports, and recall authority give the FDA leverage in the conversation that it did not have before 2022.

1
Office of the Law Revision Counsel. 21 USC 379e – Listing of Colors
2
Office of the Law Revision Counsel. 21 USC 361 – Adulterated Cosmetics
3
Office of the Law Revision Counsel. 21 USC 362 – Misbranded Cosmetics
4
Office of the Law Revision Counsel. 21 USC 331 – Prohibited Acts
5
eCFR. 21 CFR Part 700 Subpart B – Requirements for Specific Cosmetic Products
6
eCFR. 21 CFR 700.13 – Use of Mercury Compounds in Cosmetics
7
Office of the Law Revision Counsel. 21 USC 364d – Safety Substantiation
8
U.S. Food and Drug Administration. FDA Records Access Authority for Cosmetics Products
9
eCFR. 21 CFR Part 701 – Cosmetic Labeling
10
eCFR. 21 CFR Part 701 – Cosmetic Labeling – Section 701.3
11
U.S. Food and Drug Administration. Summary of Cosmetics Labeling Requirements
12
U.S. Food and Drug Administration. Registration and Listing of Cosmetic Product Facilities and Products
13
U.S. Food and Drug Administration. Modernization of Cosmetics Regulation Act of 2022 (MoCRA)
14
U.S. Food and Drug Administration. How to Report a Cosmetic Product Related Complaint
15
Office of the Law Revision Counsel. 21 USC 364g – Mandatory Recall Authority