Ingredient
5-Bromo-5-Nitro-1,3-Dioxane
5-Bromo-5-Nitro-1,3-Dioxane is flagged for pregnancy, breastfeeding, postpartum, trying to conceive, PCOS and general use. The concern behind the strongest flag is absorbed into the body and known teratogen.
- Bronidox
- 2-Bromo-2-nitropropane-1,3-diol (related compound)
- Bronopol derivative
Verdict by profile
Truva checks every ingredient against six profiles. Jump to any of them for the full assessment.
- Strongest verdict
- Not Recommended
- Its verdict for pregnancy, the profile this one is worst in
- Profiles flagged
- 6 of 6
- Counting avoid, high risk and medium risk
- Irritancy
- 4 of 5
- Higher means more likely to sting or redden
5-Bromo-5-Nitro-1,3-Dioxane and pregnancy
Not Recommended
- Absorbed into the body
- Known teratogen
- Carcinogen concern
5-Bromo-5-nitro-1,3-dioxane is a preservative that releases formaldehyde, a known human carcinogen. It was historically used in cosmetics but has been banned in the EU since 2019 due to significant safety concerns. According to ECHA and international regulatory bodies, this ingredient poses serious health risks including carcinogenicity and severe skin sensitization. Formaldehyde-releasing ingredients are of particular concern during pregnancy because formaldehyde is classified as a Category 1B carcinogen and has been associated with adverse reproductive outcomes in occupational exposure studies. The compound can also form carcinogenic nitrosamines. No level of exposure is considered safe during pregnancy. The EU has completely prohibited this ingredient in cosmetics, and ACOG guidance recommends avoiding all formaldehyde-releasing ingredients during pregnancy. Any product containing this ingredient should not be used. If you have older cosmetic products, check ingredient lists and discard any containing 5-bromo-5-nitro-1,3-dioxane or Bronidox.
5-Bromo-5-Nitro-1,3-Dioxane and breastfeeding
Not Recommended
- Infant exposure
- Carcinogen concern
- Absorbed into the body
As a formaldehyde-releasing preservative, 5-bromo-5-nitro-1,3-dioxane poses significant health risks to both the mother and potentially to breastfed infants through skin contact or inhalation exposure. The ingredient releases formaldehyde, a known carcinogen. According to the EU and ECHA, this ingredient is banned from cosmetic use due to severe safety concerns. Formaldehyde can be absorbed through skin and inhaled, creating potential exposure pathways for breastfed infants who have close skin contact with their mothers. The AAD and lactation consultants strongly advise against use of formaldehyde-releasing preservatives. This ingredient should not be present in any modern cosmetic products following current safety regulations. If you have older products containing this ingredient, discard them immediately. Choose products with safer, modern preservative systems that are explicitly labeled as formaldehyde-free.
5-Bromo-5-Nitro-1,3-Dioxane and postpartum
Not Recommended
- Carcinogen concern
- Irritant
- Common allergen
5-Bromo-5-nitro-1,3-dioxane is a banned preservative that releases formaldehyde, a known human carcinogen. This ingredient poses serious health risks regardless of pregnancy or breastfeeding status. The EU has prohibited this ingredient in cosmetics since 2019 due to its severe irritation potential, high sensitization rate, and release of carcinogenic formaldehyde. Postpartum women should not use products containing this ingredient. Check older cosmetic products and discard any containing 5-bromo-5-nitro-1,3-dioxane or Bronidox.
5-Bromo-5-Nitro-1,3-Dioxane and trying to conceive
Not Recommended
- Carcinogen concern
- Absorbed into the body
Women trying to conceive should absolutely avoid 5-bromo-5-nitro-1,3-dioxane due to its release of carcinogenic formaldehyde and overall safety profile. This ingredient is banned in the EU and should not be present in modern cosmetic products. The ingredient's carcinogenic properties and potential for systemic absorption make it completely inappropriate for use during the preconception period. If you have older cosmetic products, check ingredient lists carefully and discard any containing this preservative. Choose products with modern, safe preservative systems when preparing for pregnancy.
5-Bromo-5-Nitro-1,3-Dioxane and PCOS
Not Recommended
- Carcinogen concern
- Irritant
5-Bromo-5-nitro-1,3-dioxane is a banned preservative ingredient with serious safety concerns that apply to all users, including women with PCOS. The ingredient releases formaldehyde and is classified as a human carcinogen. According to the EU Cosmetics Regulation, this ingredient is completely prohibited in cosmetic products. Women with PCOS should avoid this ingredient just as all consumers should. There are no circumstances under which use of this ingredient is considered safe or appropriate. Check all cosmetic products, especially older items, and discard any containing this ingredient. Modern formulations use safer preservative systems. If you have PCOS and are looking for acne or skincare products, choose formulations with safe, contemporary preservatives.
5-Bromo-5-Nitro-1,3-Dioxane and general use
Not Recommended
- Carcinogen concern
- Irritant
- Common allergen
5-Bromo-5-nitro-1,3-dioxane (Bronidox) is a preservative that was used in cosmetics and personal care products but has been banned in the EU since 2019. It is a formaldehyde-releasing preservative that poses serious health risks. According to ECHA and the EU Scientific Committee on Consumer Safety, this ingredient causes severe skin irritation and allergic reactions. It releases formaldehyde, which is classified as a Category 1B carcinogen by the International Agency for Research on Cancer (IARC). The ingredient can also form carcinogenic nitrosamines under certain pH conditions. High rates of contact dermatitis and sensitization were documented with this preservative. This ingredient is prohibited in cosmetic products sold in the EU and should not be present in products following current safety standards. Consumers should check ingredient lists on older products purchased before 2019 and discard any containing 5-bromo-5-nitro-1,3-dioxane or Bronidox. Modern cosmetics use safer preservative alternatives that do not release formaldehyde. If you experience irritation from any product, discontinue use and consult a dermatologist.
Everything else flagged for the same profiles
Related ingredients
Ingredients suggested in place of 5-Bromo-5-Nitro-1,3-Dioxane, each one with its own page here.
Ingredients that raise the same concerns.
Where this came from
Truva summarises published guidance from bodies including ACOG, the FDA, the EU SCCS and the Cosmetic Ingredient Review. It has no access to your medical history and it is not a substitute for your doctor, dermatologist or midwife. These assessments have not been reviewed by a clinician, and nothing here is a diagnosis or a prescription. If you are pregnant, breastfeeding or being treated for PCOS, take the ingredient list to the person looking after you.
Assessment last pulled from the ingredient database on .
One ingredient is the easy case.
A label has thirty of them. Truva reads the whole list at once and answers for the profile you set: pregnancy, breastfeeding, postpartum, trying to conceive, PCOS, or general use.
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