4 ms·

What Are FD&C Dyes and Lakes (and How Do They Differ)?

21 points by hammock 3y ago

542458 3y ago
One thing not explained here is what “FD&C” means - it’s Food, Drug and Cosmetic Act. It just means the dye is FDA approved as being safe for humans.
- blendergeek 3y ago
  For the headline, "What Are FD&C Dyes ..." I was disappointed to see nothing about what FD&C dyes are (as opposed to a regular dye which I assumed is something like "a chemical that exhibits coloring power when dissolved").
crazygringo 3y ago
This page leads to more questions than it answers. After reading it, I still have no idea what the difference is between a dye and a lake, or why it matters, but now I realize I also don't know what blooming is, whether it matters if a dye is water- or oil-soluble, what tinting by dispersion is (and why it matters if that's different from a dye), or why I should care about "dye load". Since those all seem to be involved in the answer to the main question. Maybe there's a better page to submit to HN on this topic, because this one seems awfully confusing.
- hn_throwaway_99 3y ago
  Are you reading the same article? Literally all the questions you ask are answered, clearly, in the article, with perhaps an exception to some of the "why it matters" questions. If you see the "about" page for this company you can see that their colorants are for things like bath bombs, soaps, makeup, etc., and so you'd want different things depending on what you're trying to color (e.g. if you're coloring an oil/fat vs. water in a bath).
  - crazygringo 3y ago
    Literally the second sentence is: > Dyes must be "bloomed" before use. It does not define blooming. I still have no idea what that means. Maybe if you're an expert in this stuff already then it all makes sense. But I'm already lost when it starts by talking about blooming -- and then once it gets to aluminum salts, and strongly emphasizing that it's not elemental aluminum (which matters to the reader why...?), I realize that this is not written for the layperson.
    - margalabargala 3y ago
      Context clues tell me "blooming" probably means "putting it in water and letting it dissolve", but that's just my guess. It would be nice if they defined it.
      - eindiran 3y ago
        The article doesn't make this very clear and the way it phrases it is confusing. > Dyes must be "bloomed" before use. In their unbloomed state (i.e. in the jar) they are different color than in use. With the evident meaning: "bloomed" -> out of the jar, in the water. But blooming means precipitating the dye in whatever solution it will be in, usually using a salt like sodium bicarbonate. [EDIT] The Wiki page on lakes makes it clearer: https://en.wikipedia.org/wiki/Lake_pigment https://en.wikipedia.org/wiki/Lake_pigment
    - hn_throwaway_99 3y ago
      The paragraph is this: > Dyes must be "bloomed" before use. In their unbloomed state (i.e. in the jar) they are different color than in use. For example, our Bright Green Dye is brown in the jar, then turns a vibrant bright green when bloomed in water. It does a pretty good job, together with the rest of the article, explaining that blooming means letting it dissolve in water, at which point the color changes. I'm not familiar with dyeing at all, but "blooming" is used in a bunch of other contexts that mean similar things, e.g. "coffee blooming" (adding water to freshly ground coffee), even things like "algae blooms".
- fatbird 3y ago
  > whether it matters if a dye is water- or oil-soluble "Dyes are water soluble, and will not mix with oils." > what the difference is between a dye and a lake "Lakes are produced by coloring an aluminum salt... substrate using FD&C dyes." So a dye is soluble material; lakes are an insoluble material colored with dyes. > tinting by dispersion is Lakes disperse in the liquid; dyes dissolve into it. Presumably if you're interested in actually using dyes, this is a distinction you're already familiar with. > why I should care about "dye load" "Remember: in general, the higher the dye load, the less you'll need to achieve the color you're going for. Don't make the mistake of comparing a 70% dye load product to one with a 90% dye load."
Dwedit 3y ago
Alright, but it didn't explain what an FD&C dye was...
- djbusby 3y ago
  First paragraph: What's A Dye? A dye is a chemical that exhibits coloring power when dissolved. Dyes are water soluble, and will not mix with oils.
  - margalabargala 3y ago
    Exactly. It's talking about general dyes, while the title names a (presumably) specific sort of dye, an "FD&C" dye. Are all dyes FD&C dyes? What does FD&C mean? Those are not questions answerable by someone who read this article without further research.
    - Clamchop 3y ago
      All articles presume that the audience has some knowledge going in, but I have no explanation for why dye needs definition but the even more specific FD&C dye doesn't. (shrug)
  - kwhitefoot 3y ago
    That doesn't explain what an FD&C dye is unless you already know what FD&C stands for.
    - dylan604 3y ago
      If you're shopping at Mad Micas, you probably are. This is like someone typically that shops at Mad Mica coming to a site you are probably more custom to using and asking what LLM, CNN, etc means. A lot of the articles I've seen about the topic just naturally assume the reader already has some context and just uses acronyms without ever spelling it out nor even attempting to define on a ELI5 kind of a situation which for some reason you are expecting this site to do for you
  - 3y ago
jlas 3y ago
(Not) fun fact that I learned recently is some dyes like Red 40 are made from petroleum! https://en.wikipedia.org/wiki/Red#:~:text=The%20most%20common%20synthetic%20food,is%20mostly%20made%20from%20petroleum https://en.wikipedia.org/wiki/Red#:~:text=The%20most%20commo...
- hn_throwaway_99 3y ago
  Why is this not a fun fact? Guess I shouldn't let you know where petroleum jelly comes from...
- fatbird 3y ago
  You realize, I hope, that all plastics are also petroleum products.
  - dekhn 3y ago
    (except plastics which are not, like PLA)
- Clamchop 3y ago
  The majority of flavors, fragrances, medications, and synthesized organic chemicals of all purposes use petroleum as a precursor at some stage of their manufacture. It's a very cheap source of hydrocarbons and doesn't at all mean there is petroleum in the product.
nielsbot 3y ago
Thought the use of the word "lake" here was interesting. (Of course, not the same as a lake you can swim in): From French laque (“lacquer”), from Persian لاک‎ (lâk), from Hindi लाख (lākh), from Sanskrit लक्ष (lakṣa, “one hundred thousand”), referring to the number of insects that gather on the trees and make the resin seep out. Doublet of lakh, lac and lacquer. (https://en.wiktionary.org/wiki/lake#Etymology_4 https://en.wiktionary.org/wiki/lake#Etymology_4)
- semi-extrinsic 3y ago
  In Lower German, Norwegian and Swedish (at least), "lake" means "brine", as in pickling liquid. E.g. "saltlake" means specifically a brine that has a lot of salt. And this again comes from "lake" as in "body of water". Curious if the etymology that lake is coming via the French "lacquer" is actually the correct one, when the alternative that is coming from proto-Germanic "laki" is much closer to the actual chemical composition and way of preparation of the dye lake?

21 points by hammock 3y ago

One thing not explained here is what “FD&C” means - it’s Food, Drug and Cosmetic Act. It just means the dye is FDA approved as being safe for humans.

blendergeek 3y ago
For the headline, "What Are FD&C Dyes ..." I was disappointed to see nothing about what FD&C dyes are (as opposed to a regular dye which I assumed is something like "a chemical that exhibits coloring power when dissolved").

crazygringo 3y ago

This page leads to more questions than it answers. After reading it, I still have no idea what the difference is between a dye and a lake, or why it matters, but now I realize I also don't know what blooming is, whether it matters if a dye is water- or oil-soluble, what tinting by dispersion is (and why it matters if that's different from a dye), or why I should care about "dye load". Since those all seem to be involved in the answer to the main question. Maybe there's a better page to submit to HN on this topic, because this one seems awfully confusing.

hn_throwaway_99 3y ago
Are you reading the same article? Literally all the questions you ask are answered, clearly, in the article, with perhaps an exception to some of the "why it matters" questions. If you see the "about" page for this company you can see that their colorants are for things like bath bombs, soaps, makeup, etc., and so you'd want different things depending on what you're trying to color (e.g. if you're coloring an oil/fat vs. water in a bath).
- crazygringo 3y ago
  Literally the second sentence is: > Dyes must be "bloomed" before use. It does not define blooming. I still have no idea what that means. Maybe if you're an expert in this stuff already then it all makes sense. But I'm already lost when it starts by talking about blooming -- and then once it gets to aluminum salts, and strongly emphasizing that it's not elemental aluminum (which matters to the reader why...?), I realize that this is not written for the layperson.
  - margalabargala 3y ago
    Context clues tell me "blooming" probably means "putting it in water and letting it dissolve", but that's just my guess. It would be nice if they defined it.
    - eindiran 3y ago
      The article doesn't make this very clear and the way it phrases it is confusing. > Dyes must be "bloomed" before use. In their unbloomed state (i.e. in the jar) they are different color than in use. With the evident meaning: "bloomed" -> out of the jar, in the water. But blooming means precipitating the dye in whatever solution it will be in, usually using a salt like sodium bicarbonate. [EDIT] The Wiki page on lakes makes it clearer: https://en.wikipedia.org/wiki/Lake_pigment https://en.wikipedia.org/wiki/Lake_pigment
  - hn_throwaway_99 3y ago
    The paragraph is this: > Dyes must be "bloomed" before use. In their unbloomed state (i.e. in the jar) they are different color than in use. For example, our Bright Green Dye is brown in the jar, then turns a vibrant bright green when bloomed in water. It does a pretty good job, together with the rest of the article, explaining that blooming means letting it dissolve in water, at which point the color changes. I'm not familiar with dyeing at all, but "blooming" is used in a bunch of other contexts that mean similar things, e.g. "coffee blooming" (adding water to freshly ground coffee), even things like "algae blooms".
fatbird 3y ago
> whether it matters if a dye is water- or oil-soluble "Dyes are water soluble, and will not mix with oils." > what the difference is between a dye and a lake "Lakes are produced by coloring an aluminum salt... substrate using FD&C dyes." So a dye is soluble material; lakes are an insoluble material colored with dyes. > tinting by dispersion is Lakes disperse in the liquid; dyes dissolve into it. Presumably if you're interested in actually using dyes, this is a distinction you're already familiar with. > why I should care about "dye load" "Remember: in general, the higher the dye load, the less you'll need to achieve the color you're going for. Don't make the mistake of comparing a 70% dye load product to one with a 90% dye load."

Dwedit 3y ago

Alright, but it didn't explain what an FD&C dye was...

djbusby 3y ago
First paragraph: What's A Dye? A dye is a chemical that exhibits coloring power when dissolved. Dyes are water soluble, and will not mix with oils.
- margalabargala 3y ago
  Exactly. It's talking about general dyes, while the title names a (presumably) specific sort of dye, an "FD&C" dye. Are all dyes FD&C dyes? What does FD&C mean? Those are not questions answerable by someone who read this article without further research.
  - Clamchop 3y ago
    All articles presume that the audience has some knowledge going in, but I have no explanation for why dye needs definition but the even more specific FD&C dye doesn't. (shrug)
- kwhitefoot 3y ago
  That doesn't explain what an FD&C dye is unless you already know what FD&C stands for.
  - dylan604 3y ago
    If you're shopping at Mad Micas, you probably are. This is like someone typically that shops at Mad Mica coming to a site you are probably more custom to using and asking what LLM, CNN, etc means. A lot of the articles I've seen about the topic just naturally assume the reader already has some context and just uses acronyms without ever spelling it out nor even attempting to define on a ELI5 kind of a situation which for some reason you are expecting this site to do for you
- 3y ago

jlas 3y ago

(Not) fun fact that I learned recently is some dyes like Red 40 are made from petroleum! https://en.wikipedia.org/wiki/Red#:~:text=The%20most%20common%20synthetic%20food,is%20mostly%20made%20from%20petroleum https://en.wikipedia.org/wiki/Red#:~:text=The%20most%20commo...

hn_throwaway_99 3y ago
Why is this not a fun fact? Guess I shouldn't let you know where petroleum jelly comes from...
fatbird 3y ago
You realize, I hope, that all plastics are also petroleum products.
- dekhn 3y ago
  (except plastics which are not, like PLA)
Clamchop 3y ago
The majority of flavors, fragrances, medications, and synthesized organic chemicals of all purposes use petroleum as a precursor at some stage of their manufacture. It's a very cheap source of hydrocarbons and doesn't at all mean there is petroleum in the product.

nielsbot 3y ago

Thought the use of the word "lake" here was interesting. (Of course, not the same as a lake you can swim in): From French laque (“lacquer”), from Persian لاک‎ (lâk), from Hindi लाख (lākh), from Sanskrit लक्ष (lakṣa, “one hundred thousand”), referring to the number of insects that gather on the trees and make the resin seep out. Doublet of lakh, lac and lacquer. (https://en.wiktionary.org/wiki/lake#Etymology_4 https://en.wiktionary.org/wiki/lake#Etymology_4)

semi-extrinsic 3y ago
In Lower German, Norwegian and Swedish (at least), "lake" means "brine", as in pickling liquid. E.g. "saltlake" means specifically a brine that has a lot of salt. And this again comes from "lake" as in "body of water". Curious if the etymology that lake is coming via the French "lacquer" is actually the correct one, when the alternative that is coming from proto-Germanic "laki" is much closer to the actual chemical composition and way of preparation of the dye lake?