Introduction

Context

Every day, millions of people use cosmetics, makeup, lotions, nail polish, shampoos and other personal care products, without thinking twice before using them. Yet many of these everyday products may contain chemicals linked to cancer, birth defects or serious health risks. This raises a question, Can we trust the products that are FDA-approved and placed on shelves in stores? To explore this we will analyze data from CSCP to identify the amount and types of harmful or potentially harmful ingredients found in cosmetic products. By examining these patterns, we hope to better understand how transparent and safe the industry truly is.

Research Questions

Which categories of products contain the most hazardous chemicals?

Which companies report the most products with harmful ingredients?

What hazardous chemicals are most commonly reported?

Data

This data comes from the California Safe Cosmetics Program (CSCP), which is a part of the California Department of Public Health (CDPH). The role of CSCP is to collect and publicize information on “hazardous and potentially hazardous ingredients in cosmetic products sold in California”. This information was gathered through self-reporting. The state of California has a Senate Bill called the California Safe Cosmetics Act that was passed in 2005. This act requires cosmetic manufacturers to report all products sold that contain ingredients that cause cancer, reproductive or developmental harm. However, this data does not contain all of these products as it is still up to the manufacturers on if they choose to report. It is also stated that only companies with aggregate sales of one million dollars or more and have sold cosmetic products in California after 2006 must report, leaving many products unaccounted for. The data table consists of 22 columns and 114635 rows, with each column representing a variable and each row representing the product reported. The variables include: company/manufacturer names, product brand names, product categories, names of reported chemical ingredients, the number of reported chemicals for each product, dates of reporting, and product discontinuation or reformulation if applicable.

Results

This is a bar graph showing the relationship between the primary product type and the amount of products with harmful chemicals. On the x axis is the amount of product with harmful chemical ranging from 0 to 7000. On the y axis are the primary product types, with products like makeup, nail products and skin care products. The bar shows a significantly larger bar for the makeup category.

Figure 1: This figure displays a bar chart of the type of product and the number products that contain harmful ingredients. Harmful ingredients are self reported chemicals that have been proven to cause cancer, reproductive or developmental harm. Type of product are categorized by the type of personal care or hygiene products, for example: makeup, fragrances, skin care etc…

Based on this figure we can see that out of the primary categories for product type, makeup products (non-permanent) have by far the most products containing harmful chemicals, with around 70,000 products. Since the difference between the amount of products for makeup is so much larger than the other categories, the next largest having less than 20,000, we can analyze makeup products more in depth using the subcategories.

A horizontal bar chart displaying the ten most frequently reported hazardous ingredients in cosmetic products. The x-axis ranges from 0 to roughly 7,500 reports. The y-axis lists ingredients such as Titanium Dioxide, Silica, Retinol, and Mica. Titanium Dioxide has the longest bar, followed by Silica and Crystalline Silica. The bars show large differences between companies, with a few having drastically more reports than the rest. The appearance reveals that hazardous-ingredient reporting is uneven across companies, with certain companies contributing a much larger share of the reported products.

Figure 2: This graph shows the top five most frequently reported hazardous ingredients in cosmetic products, including Titanium Dioxide, Retinol, Silica, and Mica. Values represent simple counts of how many times each chemical was reported in the California Safe Cosmetics Program database. Each bar displays descriptive frequencies only; no statistical tests were used.

This figure shows that Titanium Dioxide is the most frequently reported hazardous ingredient, with Silica and Retinol following closely behind. These ingredients are widely used in products such as powders, foundations, lipsticks, and eye shadows, which helps explain their high frequency in the dataset. Because these chemicals, especially in airborne or inhabitable forms, have been linked to respiratory issues and potential carcinogenic risks, their widespread presence raises concerns about consumer health and industry transparency.

A horizontal bar chart showing the number of hazardous-ingredient reports by makeup subcategory. Bars are color-filled by chemical type. The x-axis shows report counts ranging from 0 to approximately 1,500, and the y-axis lists subcategories such as Lip Color, Foundations and Bases, Eye Shadow, Mascara, and others. Lip Color, Foundations and Bases, and Eye Shadow have the highest numbers of reports. Titanium dioxide appears most frequently across the majority of subcategories.

Figure 3: This graph displays the number of hazardous-ingredient reports across makeup subcategories, including Lip Color, Foundations and Bases, Eye Shadow, and others. The data come from the California Safe Cosmetics Program and are represented as simple counts. Each bar reflects descriptive frequencies only, with no statistical analysis performed.

This figure shows that Lip Color products, Foundations and Bases, and Eye Shadow account for the highest number of hazardous-ingredient reports among makeup categories. These products are applied near sensitive areas such as the mouth and eyes, which increases the potential for exposure. The high number of reports suggests that some of the most commonly used and frequently purchased makeup items may also be more likely to contain potentially harmful ingredients.

Analysis of the graph also shows that titanium dioxide is present in a large proportion of makeup products. According to the International Agency for Research on Cancer (IARC) 1, as cited by the Campaign for Safe Cosmetics, titanium dioxide (TiO₂) is classified as a carcinogen based primarily on studies showing increased lung cancer risk from inhalation exposure in animals. While these studies raise ethical concerns, they suggest that humans may also be inhaling harmful chemicals without being fully aware of their potential long-term health effects.

This is a scatterplot showing the relationship between the total number of products each company has and their propotion of discontinued or altered products. On the x axis is total number of products ranging from one to 6,00, and on the y axis is the proportion of discontinued or altered products ranging from 0 to 1. There are a large number of points around 0,0 however, on average the companies with the highest proportion tend to have a small number of products staying around the 1 to 500 range, whereas the companies with higher amounts of products have a much smaller proportion.

Figure 4: This figure shows that on average that the more products a company produces the smaller their proportion of discontinued or altered products. Each point on the graph represents a different company and they are plotted by the total number of products that company has produced and the proportion of discontinued or altered products they have. These values were self reported to the California Safe Cosemetics Program.

By looking at the trends of the points on this figure we can start to make assumptions about the relationship between the number of products a company has and the proportion of those products that have been discontinued or the hazardous chemical was removed. One of these trends is that most of the companies that have a high proportion of changed products also tend to have a smaller amount of total products. The other trend is that as the total number of products grew the proportion of changed products stayed close to zero. Based on these observations we can see that bigger or more corporate companies with high amounts of products tend to care less about changing them or discontinuing them and therefore less about the health and safety of their customers. On the other hand the smaller companies, those with less products, seem to care more about the health and safety of their customers as they tended to have the highest proportion of discontinued or altered products.

Conclusion

Being able to trust that the products used every day are safe often feels like a given. No one expects that using something as seemingly harmless as eye shadow could increase the risk of cancer or cause reproductive or developmental harm later in life. The goal of this project was to examine how much trust consumers can reasonably place in personal care products. To do this, we analyzed which types of products were most frequently associated with hazardous ingredients, identified the chemicals involved and their potential health impacts, and examined how company size influenced accountability. Increased awareness of ingredients such as titanium dioxide, identified in our research as being present in many makeup products, can help consumers make more informed decisions about which products to trust and purchase. Additionally, research from the Center for Science in the Public Interest 2 shows that titanium dioxide is not limited to cosmetics, as it is also found in popular foods such as Skittles and powdered donuts. In the United States, there is often an assumption that products available in stores are inherently safe to use or consume; however, these findings demonstrate that potentially hazardous chemicals are common in everyday products, highlighting the need for greater transparency and consumer awareness.

Currently the US is far behind the rest of the world when it comes to protecting consumers from potentially dangerous or dangerous chemicals, however they are falling far behind the rest of the world. Many nations around the world have cracked down on their regulations for ingredients in cosmetic and personal care products, restricting or even completely banning more than 1,600 chemicals from cosmetic products. The FDA however, only has nine chemicals restricted or banned.3 This data set is a representation of the inadequacy of the FDA, the fact that these chemicals were proven to cause cancer, reproductive and developmental harm but it was left up to the companies themselves to report rather than it being mandated. Instead of taking a step in the right direction and restricting or banning these harmful chemicals they have decided to take one off the list. As of November 2025 the FDA is ending the rule proposed last year “that would require testing for toxic asbestos in talc-based cosmetics”.4 That is why right now it is crucial to take a second look at the products you buy and what you use, because unfortunatly there isn’t much trust to be had.

References

  1. Safe Cosmetics. (2022, June 2). Titanium dioxide. https://www.safecosmetics.org/chemicals/titanium-dioxide/#ref22↩︎

  2. Center for Science in the Public Interest. (2025, October 21). Titanium dioxide: Hiding in Halloween candy, dairy, and more. https://www.cspi.org/cspi-news/titanium-dioxide-hiding-halloween-candy-dairy-and-more↩︎

  3. Inouye, B. (2021, August 10). On protecting consumers from Toxics in cosmetics, U.S. lags at least 80 countries | environmental Working Group. EWG. https://www.ewg.org/news-insights/news/2021/08/protecting-consumers-toxics-cosmetics-us-lags-least-80-countries↩︎

  4. Perkins, T. (2025, November 28). FDA poised to kill proposal that would require asbestos testing for cosmetics. The Guardian. https://www.theguardian.com/environment/2025/nov/28/fda-proposal-asbestos-testing-talc-cosmetics↩︎