{"paper_id":"34db346f-4ebb-41da-b4fd-6fc0c9fe3952","body_text":"Menstrual\nproducts are essential for half of the world′s\npopulation to maintain hygiene, prevent infections, provide comfort,\nand allow access to educational, occupational, and social activities\nduring menstruation.  However, menstrual\nproducts can contain chemicals of concern for human health, such as\ndioxins, pesticides, per- and polyfluoroalkyl substances, and phthalic\nacid esters (PAEs). \n − \n \n \n \n \n \n  From a human exposure perspective this is a concern, since these\nproducts are used for several days each month from menarche (average\nage 12 \n , \n ) to menopause (average age 51 ), and the vaginal and vulvar tissues have a\nhigher chemical absorption capacity compared to other skin tissues.  Additionally, these products are used during\nfertile life stages, which can be a sensitive time frame for human\nexposure, since exposure to endocrine-disrupting chemicals (EDCs)\ncan be relevant for gynecological and reproductive conditions, such\nas endometriosis, adenomyosis, and uterine fibroids. \n ,\nAmong the chemicals of concern found in menstrual products\nthere\nare PAEs, \n − \n , \n  a group of plastic additives\nincluding chemicals classified as EDCs. \n , \n  Exposure to\nsome PAEs, like the bis­(2-ethylhexyl) phthalate (DEHP), has also been\nassociated with increasing risk of cancer.  Due to these concerns, some PAEs have been regulated in several\ncountries.  In particular, since 2020,\nthe European Union limited the use of 4 PAEs, including DEHP, dibutyl\nphthalate (DnBP), diisobutyl phthalate (DiBP), and benzyl butyl phthalate\n(BBzP), in consumer products, \n , \n  to concentrations below\n0.1% by weight in plasticized materials.  These regulations have been shown to be effective in reducing human\nexposure to these chemicals. \n − \n \n \n \n  However, PAEs are still widely used in products, and high molecular\nweight PAEs, like the diisononyl phthalate (DiNP) and the diisodecyl\nphthalate (DiDP), have emerged as alternatives to the regulated ones,\neven if these substances are also showing associations with potential\nadverse effects.\nDespite the detection\nof high concentrations of PAEs in menstrual\nproducts, data on the occurrence of other plastic additives are lacking.\nAmong plastic additives, two additional classes of interest for human\nexposure are organophosphate esters (OPEs) and alternative plasticizers\n(APs). These two classes of plastic additives have been previously\ndetected in consumer products (face-masks,  textiles,  and food contact materials ) but have not been analyzed in menstrual products,\nso far. The presence of OPEs in consumer products is a concern because\nthese compounds have been linked to various health effects, including\nimmunotoxicity, neurotoxicity, and endocrine disruption.  Additionally, chlorinated OPEs, like tris­(2-chloroethyl)\nphosphate (TCEP) and tris­(2-chloroisopropyl) phosphate (TCIPP), have\nbeen classified as carcinogenic.  APs\ninclude a variety of novel plasticizers, such as citrates, adipates,\nand trimellitates, which have become widely used as a response to\nthe toxicological concerns surrounding OPEs and PAEs. \n , \n  However, information about APs toxicological properties is still\nscarce, and recent studies are showing that some of these chemicals\ncan also be linked to adverse effects. For example, acetyl tributyl\ncitrate (ATBC) and tri- n -butyl citrate (TBC) showed\nneurotoxic effects in animal studies and ATBC, diisononyl cyclohexane-1,2-dicarboxylate\n(DINCH), and di­(2-ethylhexyl) (DEHA) have shown potential thyroid\ndisruption. \n ,\nThe goals of the present\nstudy were (1) to investigate the occurrence\nof 3 classes of plastic additives, including PAEs and, for the first\ntime, OPEs and APs in different types of single-use and reusable menstrual\nproducts; (2) to assess the contribution of dermal contact with these\nproducts to plastic additives human exposure; (3) to evaluate the\nhuman health and environmental impacts associated with the use of\ndifferent menstrual products.\n\nChemicals and\nconsumables are listed in  Supporting Information .\nA total of 41 menstrual\nproducts purchased in 2024 were analyzed. Most products were purchased\nfrom local supermarkets (Barcelona, Spain) and online stores with\nnational distribution, ensuring that the sampling was representative\nof the menstrual products market in Spain. Most brands sampled are\nalso distributed in EU countries other than Spain, and brands with\nan online store provide distribution to other countries within and\noutside the EU. Some samples were obtained from products distributed\nfor free to residents of the Catalan region (Spain) as part of a regional\ngovernment health initiative to promote access to reusable menstrual\nproducts.  Since these products were obtained\nfrom brands distributed in Spain, these are also considered representative\nof the Spanish market. The products selected included single-use (10\nsanitary pads, 8 panty liners, and 9 tampons) and reusable (4 reusable\nsanitary pads, 4 menstrual underwear, and 6 menstrual cups) products.\nThis distribution reflects product usage patterns in Spain, where\nsanitary pads are the most used (60.6%), followed by panty liners\n(49.7%), menstrual cups (48.4%), tampons (42.6%), reusable pads (15.0%),\nand menstrual underwear (8.7%).  Additionally,\nto ensure the sampling was representative of the menstrual products\nmarket, samples for each product type were selected to cover different\nbrands, product lines (products from the same brand, marketed with\ndifferent names because of different properties, like scent and comfort),\nsizes, and prices (detailed information in  Table S2 ). Brands included were both commercial and private brands\nfrom different supermarket chains, allowing the coverage of a wide\nrange of price categories. Including products with different costs\n(including some distributed for free) supports representativeness\nof the sampling, since product cost significantly influences menstrual\nproduct choice due to the widespread problem of menstrual poverty.  For the single-use products, the plastic packaging\nwas also analyzed. Single-use products and packaging were analyzed\nseparately.\nFor analysis,\nrepresentative portions of each menstrual product were cut into pieces\nand weighed in glass tubes to reach a sample weight of 0.1 g. For\nsanitary pads, panty liners, reusable sanitary pads, and menstrual\npanties, 1 cm 2  squares were cut from different parts of\nthe products ( Figure S1-a ), always including\nall layers (layer in contact with the skin, absorbent layer, and external\nlayers, which included adhesives in single-use products) to obtain\nconcentrations representative of the whole product. Tampons, menstrual\ncups, and packaging samples were cut in small pieces of approximately\n1 cm 3  (tampons and cups) or 1 cm 2  (packaging),\nand pieces were randomly selected to achieve the sample amount needed\n( Figure S1-b ).\nThe extraction for\nmenstrual products and packaging was adapted from a method for plastic\nadditives in face masks.  Briefly, samples\nwere spiked with 15 μL of 1 ng/μL plastic additives internal\nstandard mixture ( Table S1 ), left to equilibrate\nfor at least 2 h, and extracted twice with 40 mL of hexane:acetone\n(1:1) using sonication for 15 min. Extracts were filtered with a glass\nfunnel filled with glass wool to remove large fibers, combined, and\nevaporated with a Turbovap evaporator to reach a volume of ∼5\nmL. The extracts were transferred to 2 mL vials with Pasteur pipettes\nin multiple steps, in which the solvent was gradually evaporated with\nnitrogen to allow the transfer of the entire extract. The empty extract\ntubes were rinsed with ∼3 mL of clean hexane:acetone to ensure\nquantitative transfer. The samples were then evaporated to incipient\ndryness using a gentle flow of nitrogen, and 500 μL of methanol\nwas added. Samples were filtered with a PTFE 0.2 μm syringe\nfilter and stored at −20 °C until analysis. Plastic additives\nwere analyzed using an ultrahigh pressure liquid chromatography triple-quadrupole\nmass-spectrometer (UHPLC-MS/MS) with a previously published method  (more details in  Supporting Information ).\nTo minimize\nblank contamination, the use of plastic labware was avoided using\nglassware washed with acetone and ethanol and burnt at 400 °C\nfor 4 h. Since contamination from plastic additives cannot be completely\navoided, each batch of samples included a method blank (empty extraction\ntube). Limits of detection (LODs) were established as the minimum\nanalyte quantity that produced a signal-to-noise ratio of 3. For samples\nabove the LOD, the blank concentrations were subtracted. The method\nwas validated in terms of recovery, sensitivity, and reproducibility\n(see  SI ). Recoveries were between 53 and\n94% for PAEs, 44–83% for OPEs, and 47–105% for APs ( Table S3 ). For some analytes (TEP, TPrP, RDP,\n4IPPDPPP, TECP, ATEC, DIPA), recoveries between 40 and 50% were considered\nacceptable, since reliable quantification was ensured using a matching\ninternal standard or a close eluting internal standard for quantification\n( Table S1 ). LODs were between 0.72 and\n71.9 ng/g for PAEs, 0.06–12.5 ng/g for OPEs, and 0.83–93.4\nng/g for APs ( Table S4 ). The RSDs for the\ntriplicate recovery experiments were <20% for all analytes except\nDBP, for which a higher variability can be expected since this compound\nis quantified as the sum of two isomers (DiBP and DnBP) ( Table S3 ). In addition, for sanitary pads, which\npresent a heterogeneous composition, reproducibility of the method\nwithin the same product and within the same batch was evaluated. The\nreproducibility within the same product was <15% and within the\nsame batch was <25% ( Table S5 ), showing\nthat the sampling strategy was representative and that no variability\nin plastic additives content was to be expected within a product batch.\nThe concentrations of plastic additives found\nin menstrual products were used to calculate the estimated daily intakes\n(EDIs) through dermal contact with these products (i.e., the intake\nof plastic additives during 1 single day of product use), using  eq  \n , adapted from previous\nstudies. \n , , \n \n \n 1 \n E D I ( n g k g b w * d a y ) = [ C ( n g p r o d u c t ) * N ( p r o d u c t d a y ) * ERF ( dimensionless ) * AF ( dimensionless ) ] / [ N U ( dim e n s i o n l e s s ) * B W ( k g b w ) ] \n where  C  is the plastic additive\nconcentration in ng/product (obtained multiplying the ng/g concentration\nby the product weight);  N  is the number of products\nused in 1 day; ERF is the easily releasable fraction, i.e., the fraction\nof chemical that is released from a product and reaches the skin;\nAF is the absorption factor, i.e., the fraction of chemical that from\nthe skin surface can be absorbed and reach systemic circulation; NU\nis the number of uses for an individual product; and BW is the average\nbody weight of women living in Spain expressed in kg.  Table S6  provides the values used for each parameter.\nGiven that the average body weight of women varies from menarche until\nmenopause, EDIs were calculated for 3 different age groups: 12–18\nyears old, 19–40 years old, and 41–51 years old. \n , \n \n  Since dermal exposure through menstrual\nproducts is still poorly understood, plastic additives ERFs for menstrual\nproducts and AFs for the vaginal and vulvar tissues are not available\nin the literature. Therefore, ERFs and AFs were set to 1 for all plastic\nadditives, assuming a worst-case scenario of 100% release of the additives\nfrom the menstrual products and 100% absorption through the skin.\nFor some of the additives included in this study, there are published\nERFs for clothing \n , \n  and AFs for normal skin. \n , \n  However, while using a worst-case scenario assumption introduces\nuncertainties, using these ERFs and AFs for menstrual products was\nconsidered inappropriate. ERFs for clothing are unreliable for textile-based\nmenstrual products, which consist of multiple layers, unlike single-layer\ngarments. Moreover, for products like sanitary pads, panty liners,\ntampons, and menstrual cups, ERFs likely differ due to different material\ncompositions. Similarly, using AFs for regular skin would underestimate\nexposure, as vaginal and vulvar skin show higher absorption, particularly\nfor low molecular weight compounds.  Under\nthis worst-case scenario assumption, the introduction of the number\nof products used in a day ( N ) in  eq  \n  is equivalent to assuming 100%\nrelease from each individual product. Zeng et al.  observed ERFs between 0.39 and 0.97 from t-shirts in dermal\nmigration experiments with a contact time of 10 h, and Wang et al.  observed ERFs between 0.06 and 0.75 in dermal\nmigration experiments with a duration of 8 h. Therefore, it is possible\nthat for some chemicals in menstrual products the ERFs could be close\nto 100% during the time that only one product is used (this time ranges\nfrom 4 to 6 h). The NU variable was added to the EDI denominator to\naccount for the fact that each reusable product will release 100%\nof its content of plastic additives over its entire product lifespan\nrather than in a single day of use. NU is a dimensionless parameter\nequal to 1 for single-use products, while for reusable products NU\nwas estimated by multiplying the average product lifespan (5 years\nfor reusable sanitary pads and menstrual underwear, 10 years for menstrual\ncups ) by the average number of menstrual\nbleeding days in 1 year (50.3 days).\nFor compounds with established\ntoxicological thresholds, risk assessment was performed in terms of\nnoncarcinogenic and carcinogenic effects using established guidelines. \n − \n \n  Briefly, noncarcinogenic risk was assessed by calculating a hazard\nquotient (HQ) for each plastic additive. The HQ was calculated by\ndividing the average daily dose (ADD) by the noncancer health reference\ndose (RfD), minimal risk level (MRL), or tolerable daily intake (TDI)\n( Table S7 ). For those compounds with more\nthan one toxicological threshold defined, the most conservative value\nwas chosen. A potential noncarcinogenic risk is considered when the\nHQ is higher than 1; otherwise, the risk is considered negligible.\nSince the RfDs, MRLs, and TDIs used are derived from chronic exposures,\nthe ADD had to be calculated for a chronic exposure duration (1 year\nor longer). The ADD was calculated with  eq  \n  using established guidelines: \n \n 2 \n A D D ( n g k g b w * d a y ) = E D I ( n g k g b w * d a y ) * EF ( d a y y e a r ) * ED ( year ) A T ( d a y ) \n where EDI is the estimated daily intake ( eq  \n ), EF is the exposure frequency,\nED is the exposure duration, and AT is the averaging time. As mentioned\nabove, EDI is the intake of plastic additives during 1 single day\nof product use. EF is the number of days these products are used in\na year. EF was set to 365 for panty liners (these products can be\nused daily), while for all other products (only used during menstruation),\nthe average menstrual bleeding duration (50.3 days/year) was used.\nED is the time that an individual is exposed to plastic additives\nthrough the use of menstrual products. As for EDIs, ADD calculations\nwere age-specific due to changes in body weight between menarche and\nmenopause, and ED was set to the exposure years considered: 7 years\n(12–18 years old), 22 years (19–40 years old), and 11\nyears (41–51 years old). AT is the time over which exposure\nis averaged and for noncarcinogenic risk is equal to the ED.  Therefore, AT was set to 2190 days (12–18\nyears old), 8030 days (19–40 years old), and 4015 days (41–51\nyears old).\nCarcinogenic risk was calculated only for carcinogenic\nadditives\nwith an available oral slope factor (SFO) ( Table S7 ). Since the SFO represents the incremental cancer risk over\na lifetime,  carcinogenic risk was evaluated\nby multiplying the lifetime average daily dose (LADD) of a plastic\nadditive by the specific SFO and by 10 –6  for unit\nconversion. If the product is lower than 10 –6 , the\ncancer risk is considered negligible; if it is between 10 –6  and 10 –4 , there is a potential cancer risk; and\nif it is higher than 10 –4  there is a high-potential\ncancer risk. The LADD was calculated using  eq  \n : \n 3 \n L A D D ( n g k g b w * d a y ) = ∑ ( E D I a g e i ( n g k g b w * d a y ) * E F a g e i ( d a y y e a r ) * E D a g e i ( year ) ) A T ( d a y ) \n where EDI is the estimated daily intake ( eq  \n ), EF is the exposure frequency,\nED is the exposure duration, and AT is the averaging time. For carcinogenic\nrisk, a cumulative dose over a lifetime is considered. Therefore,\nexposure at different life stages of a menstruator is summed together,\nand AT is set to a lifetime (as established by US EPA guidelines ), using the average life expectancy of women\nin Spain in 2024 (86.4 years).\nFor all chemicals included in this study, the toxicological thresholds\nare defined for ingestion and not for dermal uptake since there is\nnot sufficient data from human and animal studies focusing on this\nexposure pathway. Therefore, the present risk assessment has uncertainties\nrelated to extrapolation from oral to dermal exposure.\nThe\nenvironmental impact was assessed by calculating the plastic additives\nemissions from menstrual products used in Spain using  eq  \n : \n 4 \n A d d i t i v e s e m i s s i o n s ( k g y e a r ) = [ ( C ( n g p r o d u c t ) + C P ( n g p r o d u c t ) ) * N ( p r o d u c t d a y ) * U F ( d a y s y e a r ) * N W * 10 − 12 ] / [ N U ] \n where  C  is the plastic additive\nconcentration in ng/product;  C \n P  is the\nplastic additive concentration in the single-use products packaging\nin ng/product;  N  is the number of products used in\n1 day ( Table S6 ); UF is the number of days\nin a year in which the products are used (365 days for panty liners,\n50.3 days for the other products only used during menstruation); NW\nis the number of women in Spain that menstruate (12,154,865 women\nwith age between 12, average age of menarche, and 51 years, average\nage of menopause, in 2024 ); 10 –12  is the conversion factor from ng to kg; NU is the number of uses\nfor an individual product ( Table S6 ).\nStatistical\nanalyses were performed using R version 4.3.2 (R Core Team). Prior\nto statistics calculations, concentrations below LOD were substituted\nwith LOD/√2. Differences in concentrations of ∑PAEs,\n∑OPEs, ∑APs, and total plastic additives between different\ntypes of menstrual products were assessed using the Kruskal–Wallis\nrank sum test and pairwise comparisons with the Wilcoxon rank sum\nexact test with correction for multiple testing. Associations between\nplastic additives concentrations in the menstrual products and in\nthe packaging were evaluated using Spearman’s rank correlation\ncoefficients only for those compounds with a detection frequency ≥\n50% in both products and packaging (TNBP, ATBC, and TBC). Statistical\nsignificance was set at  p  < 0.05.\n\nAll\nmenstrual products had detectable concentrations of plastic additives,\nand a total of 5 PAEs, 16 OPEs, and 7 APs were detected ( Tables S8–S10 ). PAEs were detected in\nall reusable sanitary pads and menstrual cups, but showed lower detection\nfrequencies in other products. OPEs were detected in 100% of all products,\nexcept menstrual cups (detection frequency: 17%). Finally, for APs\nthe detection frequency was 100% across all products, reflecting a\nmore widespread use. Indeed, many APs are used as substitutes for\nPAEs and OPEs that are regulated or considered of concern for environmental\nand human health. \n ,\nPlastic additives concentrations\nvaried depending on the product type ( Figure  \n ). Differences were observed in terms of\nboth ng/g and ng/product concentrations (obtained by multiplying ng/g\nconcentrations by the product weights) ( Figure S2 ). For total plastic additives, significant differences were\nobserved among different products (Kruskal–Wallis rank sum\ntest:  p -value < 0.05,  Table S11 ). The highest total plastic additive concentrations were\nfound in reusable sanitary pads (median: 31856 ng/g; range: 6140 −47174\nng/g) followed by sanitary pads (median: 10014 ng/g; range: 4310–16197\nng/g) ≈ panty liners (median: 2075 ng/g; range: 271–13998\nng/g) ≈ menstrual underwear (median: 1960 ng/g; range: 424–4283\nng/g) ≈ menstrual cups (median: 1116 ng/g; range: 326–2454\nng/g) > tampons (median: 263 ng/g; range: 243–1027 ng/g).\n( Figure  \n ,  Table S11 ).\n∑ PAEs, ∑ OPEs, ∑APs,\nand total plastic additives\nconcentrations (∑ PAEs + ∑ OPEs + ∑ APs) (ng/g)\nin sanitary pads, panty liners, tampons, reusable sanitary pads, menstrual\nunderwear, and menstrual cups (note the different scales).\nConsidering the different classes of additives\nanalyzed,\nreusable\nsanitary pads had the highest concentrations of PAEs (median: 28856\nng/g; range: 5019–42193 ng/g) and OPEs (median: 1906 ng/g;\nrange: 158–4068 ng/g), but the highest concentrations of APs\nwere observed in the single-use sanitary pads (median: 8873 ng/g;\nrange: 2830–11455 ng/g). Tampons had the lowest concentrations\nof PAEs (median: < LOD ng/g; range: < LOD-616 ng/g) and APs\n(median: 145 ng/g; range: 113–525 ng/g), while the lowest OPEs\nconcentrations were found in menstrual cups (median: < LOD ng/g;\nrange: < LOD-98.0 ng/g) ( Figure  \n ). The differences in concentrations between different\nproducts were significant for all classes of additives (Kruskal–Wallis\nrank sum test:  p -value <0.05). However, even if\nclear differences in median concentrations were observed among product\ntypes, pairwise comparisons showed statistically significant differences\nonly between certain types ( Tables S12, S13, S14 ). The differences in concentrations might be attributed to product\ndesign. Tampons consist of an absorbent material covered by a thin\nsynthetic fiber to facilitate application, while sanitary pads and\npanty liners have multilayer compositions with one or more plastic\nlayers. Despite the similar design of sanitary pads and panty liners,\ntheir composition can differ, since sanitary pads are designed for\nregular/abundant menstrual flow, while panty liners are made to retain\nsmall losses of blood/urine. Reusable sanitary pads and menstrual\nunderwear are different from single-use products since these are made\nof textiles, often including synthetic fibers and a waterproof layer.\nLastly, menstrual cups differ from all other products and are made\nsolely of silicone or thermoplastic elastomer (TPE). Differences in\nconcentrations might also be due to the use of different polymers\nand materials. However, since most products are composed of a combination\nof multiple polymers that varies between different brands ( Table S2 ), it is not possible to conclude if\ndifferences in plastic additive concentrations are driven by the materials\nused.\nAPs were the main plastic additives in sanitary pads,\npanty liners,\nand menstrual underwear, but not in tampons, in which OPEs were the\ndominant compounds, and reusable sanitary pads and menstrual cups,\nin which PAEs were the dominant compounds ( Figure  \n ). As mentioned earlier, APs are used as\nreplacements of PAEs and OPEs in many applications, including plastic\nand textile materials, \n , \n  and their more widespread detection\nmight reflect this shift. In most menstrual products, PAEs concentrations\nwere higher than OPEs, similar to other plastic-based products, such\nas face masks, \n , \n  textiles, \n , \n  and food contact materials. \n , \n  Only in tampons and\nmenstrual underwear were OPEs found in higher concentrations than\nPAEs. Despite the regulation of some PAEs, these compounds are still\nwidely used in consumer products. It has been hypothesized that the\npresence of PAEs in menstrual products, such as sanitary pads and\npanty liners, might be coming from the plastic materials used on the\ntop/bottom layers. PAEs might also be used in sanitary pads and panty\nliners in the adhesives added to these products or as fragrance fixatives,\nsince previous studies have observed higher PAEs concentrations in\nsanitary pads with a scent applied compared to those without a scent. \n , \n  The sample selection of the present study included both products\nwith and without a scent applied, but no clear differences in PAEs\nconcentrations and profiles were observed between scented and unscented\nproducts ( Figure S3 ). However, since the\npresence of scents was not a factor driving the sample selection,\nthis comparison might be limited by the low number of samples of sanitary\npads without a scent and panty liners with a scent applied. PAEs are\nalso widely used in the textile industry to produce synthetic fibers\nand to give textiles waterproof properties.  A waterproof layer is always included in reusable menstrual products,\nand most of the products included in this study had at least one textile\nlayer made of a synthetic fiber, such as rayon, polyester, and elastane\n( Table S2 ). Additionally, PAEs’\npresence in menstrual underwear and reusable sanitary pads might be\ndue to the presence of these compounds in dyes, textiles inks, and\nother processing aids and water used during textiles and product production.  Previous studies also hypothesized that PAEs\nin menstrual products might be coming from the product packaging.\nIn the present study PAEs, OPEs, and APs were detected in the packaging\nof single-use products ( Table S15 ), and\na positive correlation between the concentrations in the product and\nin the packaging was significant only for TBC and ATBC in panty liners\n( Table S16 ). This suggests that the packaging\nmight indeed be a source of plastic additives in menstrual products\nbut that this might depend on the materials used in the product and/or\npackaging since associations were only observed for panty liners.\nAverage\npercentage contribution of PAEs, OPEs, and APs to total\nplastic additives concentrations in sanitary pads, panty liners, tampons,\nreusable sanitary pads, menstrual underwear, and menstrual cups.\nVariability in composition between different products\nwas also\nobserved within the three classes of additives analyzed. Among the\n5 PAEs detected in menstrual products, DEHP and DiNP were the major\ncomponents in reusable sanitary pads and menstrual underwear ( Figure  \n ). DEHP concentrations\nin reusable sanitary pads (median: 22825 ng/g; range: 4913–41929\nng/g) were at least 1 order of magnitude higher than in menstrual\nunderwear (median: 161 ng/g; < LOD-400 ng/g). DiNP was only detected\nin one sample of reusable sanitary pads (14135 ng/g) and one sample\nof menstrual underwear (2077 ng/g) from the same brand, but at high\nconcentrations. As for DEHP, DiNP concentrations in reusable sanitary\npads were higher than in menstrual underwear. This is consistent with\nseveral studies reporting DEHP and DiNP among the main PAEs detected\nin textile materials. \n − \n \n \n  DEHP is the PAE consumed in greatest quantities by the textile industry,\nand, similar to our findings, most of the literature on textile-based\nproducts found DEHP to be the PAE present in the highest concentrations.  An additional PAE, DiDP, was detected in all\nreusable sanitary pads but at low concentrations (median: 91.1 ng/g;\n54.7–192 ng/g) compared to DEHP and DINP. This PAE has also\nbeen detected in other textile products. \n , , \n  DEHP (median: 116 ng/g; 36.1–1003\nng/g) and DiNP (median: < LOD ng/g; < LOD-1477 ng/g) were also\nmajor components in menstrual cups, but with lower concentrations\nthan other reusable products. Additionally, in menstrual cups DBP\nwas found as a major additive, since it was detected in 5 out of 6\nmenstrual cups (median: 138 ng/g). DiDP was also detected in half\nof the menstrual cups. Interestingly, DiNP was detected only in TPE\ncups ( Figure S4 ). The presence of PAEs\nin menstrual cups can be expected since these compounds are often\nused to improve the flexibility of plastic materials. For single-use\nproducts, DBP, DEHP, DiNP, and DiDP were also the compounds most frequently\ndetected, but the detection frequencies were lower, and their contribution\nchanged depending on the product type.\nHowever, PAEs results\nin sanitary pads, panty liners, and tampons\ndiffered from those of previous studies \n − \n \n  ( Tables S17, S18 ). DBP was not detected in single-use sanitary\npads from our study but was detected in all sanitary pads analyzed\nin previous studies. These studies reported the DBP isomers separately\nwith median concentrations between 73.0 and 1424 ng/g for DiBP and\nbetween 83.3 and 909 ng/g for DnBP. Additionally, DEHP (detected only\nin one sample from our study) and DMP (not analyzed in our study)\nwere also detected in most of the sanitary pads from previous studies.\nPAEs in tampons and panty liners were only reported in one study by\nGao and Kannan.  For DEHP, concentrations\nfrom the Gao and Kannan study (mean: 744 ng/g for tampons, 2070 ng/g\nfor panty liners) were at least 1 order of magnitude higher than those\nin our study (mean: 14.5 ng/g for tampons, 121 ng/g for panty liners).\nIn the Gao and Kannan study, DiBP and DnBP were quantified separately\nand found to be in both product types. In our study, DiBP and DnBP\nwere not found in tampons but were quantified together in several\npanty liners with concentrations lower than those reported in the\nliterature. These differences, observed between our study and previous\nliterature reports, might be due to changes in PAEs legislation and\nproduction since the products in our study were collected during 2024,\nwhile the products in previous studies were bought between 2016 and\n2019. \n − \n \n  The differences might also be due to differences\nin PAEs legislation between the countries where the samples were purchased.\nFor example, the EU limits the application of BBzP, DBP, DEHP, and\nDiDP in most consumer products, while the US regulates the same PAEs\nonly in child toys.  Further, the analyzed\nPAEs in the current study differ from those of previous studies, and\nthis discrepancy might also affect the differences observed in terms\nof ∑ PAE concentrations.\nOPEs also differed between\ndifferent menstrual products ( Figure  \n ). TNBP was detected\nonly in single-use products and was the dominant OPE in sanitary pads\nand panty liners with concentrations between 110 and 319 ng/g (median:\n236 ng/g) and between < LOD-193 ng/g (median: 22.4 ng/g), respectively.\nTNBP was also widely detected in tampons (detection frequency: 78%)\nbut at lower concentrations (median: 11.1 ng/g; range: < LOD-99.7\nng/g). A wide variety of other OPEs were detected in sanitary pads\nand panty liners, but with detection frequencies <50% and concentrations\nat least 1 order of magnitude lower than TNBP ( Table S9 ). TNBP is one of the OPEs most widely used as plasticizer\nand this might explain its wide detection only in single-use products.  In tampons, the dominant OPE was TCEP (median:\n24.6 ng/g; range: 11.7–82.7 ng/g), which was detected in all\nsamples with concentrations comparable to those of TNBP. TCEP was\nalso detected in one sample of menstrual underwear at a high concentration\n(216 ng/g). However, the main OPE in reusable sanitary pads and menstrual\nunderwear was TPHP, which was detected in 100% of both types of products\nat high concentrations (median: 820 ng/g in reusable sanitary pads;\n316 ng/g in menstrual underwear). TPHP is known to have applications\nin textiles and textile coatings.  In\nmenstrual cups, TEP was the only OPE detected, but only in one of\nthe samples analyzed.\nLastly, among the APs, ATBC was the dominant\ncompound in all single-use\nproducts and menstrual cups ( Figure  \n ). The highest ATBC concentrations were found in sanitary\npads (range: 2714–11314 ng/g) and panty liners (range: <\nLOD-13563). ATBC is a popular alternative to DEHP and is currently\nwidely used as plasticizer in various applications, including medical\ndevices, cosmetics, and food packaging.  Therefore, its widespread detection at high concentrations in plastic-based\nmenstrual products is perhaps not surprising. In textile-based menstrual\nproducts, ATBC was detected only in one reusable sanitary pad, and\nthe dominant AP was DEHA, which was detected in all samples of these\nproducts. DEHA concentrations ranged between 71.3 and 1663 ng/g in\nreusable sanitary pads and 148–1926 ng/g in menstrual underwear.\nDEHA was also detected in some samples of sanitary pads and menstrual\ncups but at lower concentrations ( Table S10 ). DEHA is another popular AP with various applications, including\ntextile materials.  DINCH, detected in\na few single-use products, was detected in all TPE menstrual cups\nand not in the silicone ones ( Figure S4 ). DINCH is a plasticizer used to produce flexible plastic articles,  and this might explain its presence in TPE cups,\nwhich need to be flexible to ensure functionality.\nTo\nestimate the contribution of dermal contact with menstrual products\nto plastic additive exposure, the EDIs for the different product types\nwere calculated ( Table  \n ).\nThe highest EDIs were\nobserved for the youngest age group since\nthe average body weight is the lowest for this group. Looking at the\ndifferent types of products, the highest EDIs were observed for single-use\nsanitary pads, and the lowest were observed for menstrual cups for\nall classes of additives. While some reusable products had higher\nPAEs and OPEs concentrations than single-use products ( Figure  \n ), the EDIs for these additives\nin reusable products were lower than in single-use products. This\nis due to the different use habits. An individual who menstruates\nwill use approximately 6 single-use sanitary pads during a day, and\nin this study, the worst-case scenario (100% of the additive in the\nproduct is released to the skin) was assumed. For reusable products,\nthe worst-case scenario assumption was similar, but it was considered\nthat each product will release 100% of the additives through its entire\nlife cycle. This was achieved by introducing in the EDI formula denominator\n( eq  \n ) the number of\nuses for an individual product and therefore assuming that the plastic\nadditives in reusable products will be released in a constant amount\nat each use. This is an assumption that might not reflect real-life\nsituations since part of the chemicals will be released during the\ncleaning of these products between uses. Additionally, the release\nof plastic additives might change at different stages of use of the\nproducts. It has been shown that the highest amounts of microfibers\nare released from clothes during the first 1–4 washes. \n , \n  This might also be the case for plastic additives. Additionally,\nthe abrasion of reusable menstrual product fibers during washing might\nalso influence the release of these chemicals from the product to\nthe skin.\nWhen dermal contact with menstrual products was compared\nto other\nexposure routes, it was observed that the use of some menstrual products\nmight contribute significantly to human exposure to plastic additives.\nStarting from PAEs, mean EDIs for sanitary pads ( Table  \n ) were comparable to those for\nexposure through the diet, which is considered the main route of exposure\nto these compounds. \n − \n \n \n  Mean EDIs for dietary intake vary between 104 and 13000 ng/kg bw/day\nfor DEHP \n , , − \n \n  and 212–61000 ng/kg bw/day for DiNP. \n , , \n  Mean EDIs for reusable sanitary pads were\ncomparable to the lowest estimates reported in the literature for\ndust ingestion, another major PAEs exposure route (range: 99 and 3980\nng/kg bw/day \n − \n \n ). EDIs for PAEs in panty liners, tampons, and menstrual\nunderwear were of the same order of magnitude of the lowest estimates\nfor air inhalation (range: 6.35–360 ng/kg bw/day \n , , , \n ) and dermal exposure measured with skin wipes (range:10–1220\nng/kg bw/day \n , , \n ). Only for menstrual cups were ∑ PAEs EDIs well below estimates\nfor other exposure routes. Considering the OPEs, the highest mean\nEDIs were observed for sanitary pads. The mean EDI for ∑ OPEs\nin sanitary pads were higher than those reported for dietary intake\n(range: 0.97–103 ng/kg bw/day \n , − \n \n \n \n \n \n ), which is considered the main exposure route for OPEs. EDIs for\nall other types of products except menstrual cups were comparable\nto those reported for ∑ OPEs through other exposure routes,\nincluding air inhalation (range: 1.75–9.2 ng/kg bw/day \n − \n \n \n ), dust ingestion (range: 0.07–23 ng/kg bw/day \n , , \n ), and dermal contact with dust\n(range: 5.89–17 ng/kg bw/day \n , \n ). For menstrual\ncups, the EDIs for ∑ OPEs were at least 2 orders of magnitude\nlower compared to other menstrual products and other exposure routes.\nLastly, for APs, comparison with other exposure routes was more difficult\nto realize due to the limited amount of human exposure data for these\ncompounds. The highest EDIs for APs were observed for sanitary pads,\nand these might be comparable to EDIs for dietary intake. Two studies,\nincluding several APs in different food matrices, estimated median\nEDIs for ∑ APs through the diet of 244 ng/kg bw/day for adults\nliving in Spain and of 1515 ng/kg bw/day for adults living in Sweden. \n , \n  Additionally, a recent study, analyzing several APs in plant-based\nfood collected in Belgium, Germany and the UK, has calculated a mean\nEDI for ∑ APs of 610 ng/kg bw/day for a fully vegan diet.  However, other studies on food matrices reporting\nonly few APs found higher EDIs through food consumption (87000 ng/kg\nbw/day for DINCH intake through the diet  and 30000 ng/kg bw/day for DEHA through soft drink consumption ). EDIs for APs through dermal contact with other\nmenstrual products, except menstrual cups, were at least 1 order of\nmagnitude lower than for sanitary pads and were comparable to intake\nthrough other APs exposure routes: inhalation of indoor air (15–358\nng/kg bw/day for ATBC; 6.52–12.1 ng/kg bw/day for TBC)  and dust ingestion (2.16–14.4 ng/kg bw/day\nfor ∑APs). \n ,\nIn summary, in many cases,\nthe EDIs for plastic additives through\ndermal contact with menstrual products were comparable to those estimated\nfor other important exposure pathways. However, it is important to\nhighlight that the EDI calculations were performed assuming a worst-case\nscenario of 100% dermal uptake, which probably differs from a realistic\ncase. Previous studies measuring the release of chemicals from clothing\nfound ERFs ranging between 0.06 and 0.75 for OPEs, 0.28–0.98\nfor PAEs, and 0.33–0.57 for APs. \n , \n  Similar ERFs\nvalues might be expected for menstrual products, especially those\nmade of textiles, but they might vary depending on the material composition.\nAlso, AFs for plastic additives are expected to be lower than 1, since\nAFs measured these chemicals through regular skin are comprised between\n0.13 and 0.75. \n ,\nNoncarcinogenic\nrisk estimates were well below thresholds for toxicological effects\nfor all types of menstrual products ( Figure  \n ). The noncarcinogenic risk was negligible\neven when the different additives were added together, since the highest\nHQ value obtained for the total plastic additives was 1.7 × 10 –2 . The noncarcinogenic risk was negligible for all\n3 age groups considered, since the risk estimates for the youngest\nage group (highest EDIs due to the lowest body weight) were well below\nthreshold. On the contrary, for the carcinogenic risk, some products\nwere above the threshold for cancer effects ( Figure  \n ). However, all carcinogenic risk values\nwere below 1 × 10 –4 , above which there would\nbe a high risk. The carcinogenic risk was above threshold for 3 out\n10 sanitary pads, 3 out of 8 panty liners, and 2 out of 4 reusable\nsanitary pads. The cumulative cancer risk was driven by the presence\nof high concentrations of DEHP and DEHA in these products. It is important\nto note that this assessment might overestimate the risks for human\nhealth since calculations were based on worst-case scenario estimates\nof 100% dermal uptake. Additionally, this assessment has the drawback\nthat toxicological thresholds used are defined for oral exposure and\nnot for dermal exposure and this adds additional uncertainties. However,\nit is important to highlight that dermal exposure through menstrual\nproducts use is only one of the human exposure pathways to plastic\nadditives. When added to other exposure pathways (e.g., food or dust\ningestion), the use of menstrual products might contribute to increasing\nplastic additives exposure to levels exceeding the thresholds for\nhuman health risks for people who menstruate. Further, it is important\nto consider that these products are used during fertile life stages,\nand this exposure might be relevant for reproductive health, since\nexposure to EDCs is a known risk factor for reproductive effects. \n ,\nNoncarcinogenic\n(age group 12–18 years old) and carcinogenic\nrisk estimates for total plastic additives concentrations in sanitary\npads, panty liners, tampons, reusable sanitary pads, menstrual underwear,\nand menstrual cups. The dashed red lines indicate the threshold over\nwhich a risk for human health is considered.\nAssuming\na worst-case scenario of 100% release to the environment, the highest\nestimates for the release of plastic additives from the use of menstrual\nproducts in Spain were found for single-use products ( Table S18 ). The estimates of the release of plastic\nadditives to the environment from sanitary pads (median: 225 kg/year;\nrange 76.9–213127 kg/year), panty liners (median: 82.1 kg/year;\nrange: 4.96–2039 kg/year), and tampons (median: 472 kg/year;\nrange: 12.1–1560 kg/year) were at least 1 order of magnitude\nhigher than for reusable menstrual products. This is due to the higher\nnumber of single-use products consumed and to the high concentrations\nof plastic additives found in the packaging of these products ( Table S15 ). Among the reusable products, reusable\nsanitary pads (median:7.33 kg/year; range: 1.37–12.5 kg/year)\nand menstrual underwear (median: 1.05 kg/year; range: 0.12–1.75\nkg/year) showed comparable environmental impact. Menstrual cups were\nthe products resulting in the lowest release estimates (median: 0.02\nkg/year; range: 0.01–0.03 kg/year). Despite the highest release\nestimates being found for single-use products, plastic additives release\nfrom reusable products might be more concerning (in particular, from\nreusable sanitary pads, which showed the highest plastic additives\nconcentrations). Single-use products are disposed of as waste directly\nafter use and are expected to enter a landfill or waste incineration.\nFor reusable products, the release of plastic additives to the environment\nis expected before these products enter the waste cycle, since some\nchemicals will be released during their washing between uses. Therefore,\nthe plastic additives in reusable products might be released to wastewater\nand enter the water cycle. This is of concern because wastewater treatment\nplants are not always efficient in reducing plastic additives contamination.\n\nThis study detected a\nwide range\nof plastic additives, including\nPAEs, OPEs, and APs, in both single-use and reusable menstrual products.\nWhile PAEs have been previously reported in single-use products, \n − \n \n  this is the first study to detect them in reusable products. Moreover,\nwe report for the first time the presence of OPEs and APs in menstrual\nproducts, which had not been investigated until now. Since more than\n13.000 plastic additives exist,  it is\nto be expected that more of these chemicals might be in use in these\nproducts. In many menstrual products, APs were the dominant additives,\nreflecting their widespread use. However, despite their growing use\nin consumer products, information about human exposure to these chemicals\nis still scarce, and more information about their toxicological properties\nis needed.\nThe EDIs presented in this study show that the dermal\ncontact with\nmenstrual products might be a significant exposure pathway. This is\nof concern for the health of people who menstruate, as they are already\nexposed to PAEs, OPEs, and APs through other routes (e.g.; diet, air\ninhalation). As a consequence, people who menstruate might suffer\nhigher cumulative exposure to these additives, increasing their vulnerability\nto the associated health effects. However, these calculations were\nbased on a worst-case scenario that probably does not reflect real-life\nsituations. The main factor hindering the calculation of realistic\nestimates is the lack of knowledge about dermal exposure. To better\nunderstand dermal exposure through menstrual products, it is important\nto test the release of plastic additives from these products under\nrealistic conditions. The release of some of these chemicals from\nother types of consumer products, such as clothing or other fabric\nproducts, has been tested using migration experiments with sweat and\nsebum to simulate the surface layer of the skin. \n , \n  These migration assays should be adapted to menstrual products to\nalso study the effects of vaginal and menstrual fluids on the release\nof these chemicals. Additionally, to complete the description of dermal\nexposure to plastic additives through menstrual products, AFs for\nvaginal and vulvar tissues should be derived. It has been demonstrated\nthat some plastic additives can be absorbed into the skin. However,\nthe vulvar and vaginal tissues are known to have a higher absorption\ncapacity for chemicals, and new models might be needed to measure\nabsorption through this type of skin. Since the worst-case scenario\nestimates showed that some products might be associated with carcinogenic\nrisks, future studies focusing on the determination of these dermal\nexposure parameters are a priority to provide a more realistic risk\nassessment.\nAnother important aspect to consider about the presence\nof plastic\nadditives in menstrual products is the potential environmental impact.\nThe use of all types of menstrual products might contribute to the\nrelease of plastic additives to the environment through waste disposal\nand the washing of reusable products. The highest release of plastic\nadditives from menstrual products was found for single-use products,\nand this was partly due to their packaging, which is directly introduced\nin the waste-cycle. Even if the packaging might not contribute significantly\nto human exposure, since it is directly disposed, strategies to reduce\nthe content of chemicals of concern in the packaging as well as to\nreduce the packaging amount should be considered to reduce the impact\nof these products. However, the chemical content is only a part of\nthe environmental impact considerations for these products. This information\nshould complement life cycle assessment studies, considering other\nenvironmental aspects to properly assess the impact of menstrual\nproducts.","source_license":"CC-BY-4.0","license_restricted":false}