What is Carcinogens

Carcinogens: Recently, popular brands of aerosol dry shampoo were recalled, after it was found that they were contaminated with a chemical called benzene that can cause cancer.

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What is Carcinogens Mean

The term “carcinogen” denotes a chemical substance or a mixture of chemical substances which may induce cancer or increase its incidence.

Categories of Carcinogens

Chemical Carcinogens (including those from Biological Sources):

A variety of chemical effluents from industry and environmental pollutants from automobiles, residences, and factories eg. Acrylamide chemicals in tobacco smoke, benzene etc.
The majority of chemical carcinogens require metabolic activation for their carcinogenic effects.

Physical Carcinogens:

Physical carcinogens include ultraviolet rays from sunlight and ionizing radiation from X-rays and from radioactive materials in industry and in the general environment.
Repeated local injury (e.g., wounding) or recurring irritation (e.g., chronic inflammation) to a part of the body are other examples of potential physical carcinogens.

Oncogenic (cancer-causing) Viruses:

A number of viruses are suspected of causing cancer in animals. Eg. human papillomaviruses, the Epstein-Barr virus, and the hepatitis B virus, all of which have genomes made up of DNA.
Human T-cell leukemia virus type I (HTLV-I), which is a retrovirus (a type of RNA virus), is linked to tumour formation in humans.

The International Agency for Research on Cancer (IARC), a branch of the World Health Organization that monitors cancer research, has listed more than 400 chemical agents as carcinogenic, probably carcinogenic, or possibly carcinogenic.

Carcinogen Benzene Effects

Benzene: colorless or light yellow liquid at room temperature. It has a sweet odor and is highly flammable.
Some industries use benzene to make other chemicals that are used to make plastics, resins, and nylon and synthetic fibers.
Benzene is also used to make some types of lubricants, rubbers, dyes, detergents, drugs, and pesticides.

Why is Benzene used in Dry Shampoos?

Spray-on personal-care products like dry shampoos often contain propellants like propane and butane, which are petroleum distillates made by refining crude oil.
In a typical aerosol, the propellant is a gas under pressure above the content.
The gas pushes down on the liquid, forcing it out of the valve when it is opened. The liquid is a mix of product and liquified gas.
Some of the most common propellants in deodorant body spray are hydrocarbons, eg. Butane, isobutane, propane.
Benzene is not intentionally added but appears as a contaminant while adding the other hydrocarbons.

Regulations on Chemicals used in Industries

Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH): A European Union regulation, REACH addresses the production and use of chemical substances, and their potential impacts on both human health and the environment.
The Toxic Substances Control Act (TSCA): It a US law that requires reporting, record-keeping and testing requirements, and restrictions relating to chemical substances.
Chemical Regulation in India: There is currently no REACH-like or TSCA-like regulations for chemicals in India. The two sets of regulations related to chemicals are:
- Manufacture, Storage And Import Of Hazardous Chemical (Amendment) Rules (2000)
- Ozone Depleting Substance (R&C) Rules (2000)