Evidence map›Paper›PMID 42240731›Full record

ArticleCurrent environmental health reports2026

Chemicals of Concern in Chemical Hair Straightening Products: A Scoping Review.

Emily Weaver, Marissa Chan, Lariah Edwards, Ami R Zota

Abstract readScoping Review
In one paragraph

Article in Current environmental health reports, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

4 authors.

Emily Weaver *Department of Environmental Health Sciences, Columbia University Mailman School of Public Health, New York, NY, 10032, USA. ebw2145@cumc.columbia.edu.
Marissa Chan *Department of Environmental Health Sciences, Columbia University Mailman School of Public Health, New York, NY, 10032, USA.
Lariah EdwardsDepartment of Environmental Health Sciences, Columbia University Mailman School of Public Health, New York, NY, 10032, USA.
Ami R ZotaDepartment of Environmental Health Sciences, Columbia University Mailman School of Public Health, New York, NY, 10032, USA.

Funding

California Breast Cancer Research Program B28TP5728, 23UB-651
6 · The paper itself

Abstract

purpose of reviewChemical hair straighteners may contribute to adverse health outcomes, particularly among women of color, due to their higher use of these products. However, there is limited research on which chemical ingredients and contaminants may be the most putative agents. We conducted a scoping review to summarize the existing exposure assessment literature on chemicals of concern in two popular types of chemical hair straighteners (chemical relaxers and keratin treatments) and provide recommendations for future research. RECENT

findingsTwenty-one studies and reports used one or more of the following methods to identify chemicals of concern: product testing, ingredient label analysis, biomonitoring, and air monitoring. Multiple chemicals were characterized in these products including formaldehyde, formaldehyde releasing preservatives (FRPs), volatile organic compounds, fragrance ingredients, metals, and endocrine-disrupting chemicals (EDCs) (e.g., phthalates, phenols, and parabens). Chemical composition varied by product type, with keratin treatments more frequently containing formaldehyde or FRPs and relaxers containing EDCs and fragrance ingredients. In addition to assessing potential exposures for consumers, several studies highlighted the potential for higher exposures in salon workers. Multiple chemicals of concern, including endocrine active and carcinogenic chemicals, were identified in these products, and composition varied by product type. Future research should use new approaches, such as exposomics, to understand the full extent of environmental exposures among consumers and salon workers. Community-informed interventions are also imperative for reducing chemical exposures of concern and related health outcomes.

Indexed as

Environmental ExposureHair PreparationsEndocrine DisruptorsFormaldehydeHumansPerfumeEndocrine DisruptorsFormaldehydeHair PreparationsPerfumeChemical straightenersEndocrine disrupting chemicalsFormaldehydeKeratin treatmentsPersonal care productsRelaxersWomen’s health

Identifiers

PMID42240731
PMCPMC13236817

What OpenQuestion holds

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LicenceCC BY-NC-ND
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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.