On the Skeptics stack exchange we have a question about burned toast being used as a treatment for poison, the idea being that burned toast acts as activated carbon.

We are skeptical due to the fact that gas activation requires heating to high temperature, but don't have the chemistry to rule out toast as a source of activated carbon.

My instinct tells me that:

  1. Toast is not good source of carbon
  2. Activation is not easily done in your average kitchen.

Can someone answer those 2 questions?

  1. Is toast a good source of carbon
  2. Can activated carbon be produced in your average kitchen without training or any special supplies?

1 Answer 1


Is toast a good source of carbon is quite a broad question without considering the type of toast we're referring to. Even if do stick to a particular toast, what makes a good carbon source sounds a little too vague.

As a side note, recent researches have led to the production of a low cost multi-functional carbon foam from bread. [Source]

As a rough estimate, let's consider we're talking about white bread. 100 grams of white bread consists of 49 grams (i.e. approximately 16%) of carbohydrates. [Source] For the sake of simplicity, let's assume all of the carbohydates to be monosaccharides, specifically glucose. (This definitely isn't the case). The molecular formula of glucose is $\ce{C6H12O6}$. If we calculate the percentage-by-mass composition of carbon in glucose, we get the value as 40%. 40% of 49 grams is 19.6 gram, or in other words, bread consists of (very roughly) 19.6% carbon.

I'm unsure of whether or not that makes it a good source. Reading this article tells me that a rough estimate for the carbon content in wood (it is about some conifers but nevertheless good for rough estimates) is about 45–50%.

The production of activated carbon is undertaken generally in two ways: [Source]

  • Physical activation: It requires an inert atmosphere of nitrogen or argon along with very high temperatures (600–1200 °C).
  • Chemical activation: Strong acids, bases or salts and a lower temperature is required (450–900 °C).

Theoretically the chemical method seems appealing but in a practical sense it is not advisable to carbonize materials in a home-kitchen as the fumes evolved contain carbon-monoxide which is extremely toxic.

  • $\begingroup$ So on a scale of 1 to 10, would you say that the average burnt toast would have properties of activated charcoal? vis adsorbtion powers? $\endgroup$
    – Nav
    May 8, 2017 at 16:16

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