Do dish detergents contain toxic ingredients?
I’m pretty sure it’s a bad idea to injest it. Remember the whole Tide Pod fiasco? Though that was laundry detergent, which I’d imagine is more concentrated the dish detergent. But I’m no expert.
Yes. They do. Saponification requires chemicals. Some detergents have more than others.
Dawn ingredients - Ingredients
Alcohol Denatured, C10-16 Alkyldimethylamine Oxide, Colorants, Fragrances, Methylisothiazolinone, PEI-14 PEG-24/PPG-16 Copolymer, Phenoxyethanol, PPG-26, Sodium Chloride, Sodium Hydroxide, Sodium Laureth Sulfate, Sodium Lauryl Sulfate, Water, C9-11 Pareth-8
Without going to a wall of text - some references
Two cites from the scary end-
If you want to make your own or more natural -
https://tinyurl.com/ycdsh4ly
If you’re worried use very little and rinse very well.
Dishwasher detergent is even worse than liquid dish soap. That crap will kill you dead! 
I am only asking because someone on the Quora Q&A website said it was not advisable to wash vegetables with dish washing (not dishwasher) detergent,as it contained toxic ingredients that would be absorbed by the vegetable. I have no qualms about using it for general cleaning.
As a Chemical Engineer, I’ve seen the rise of not trusting Science when it comes to chemicals or household products. This is the same as not trusting Science when it comes to Climate change. You cannot have it both ways. Both are Science deniers.
For toxicity of any product, you can lookup the MSDS - the Material Safety Data Sheet. This is the method agreed by all scientists to identify health and other hazards associated with almost all products. Scientists have put a lot of effort into developing these lists, so before you put your faith in some website called treehugger, I urge you to reconsider.
Here is the MSDS for Dawn dish detergent http://sds.chemtel.net/webclients/cheneybrothers/540015SDS.pdf
Here is the toxicological information -
Product Information
Information on likely routes of exposure
Inhalation No known effect.
Skin contact No known effect.
Ingestion No known effect.
Eye contact Irritating to eyes.
Delayed and immediate effects as well as chronic effects from short and long-term exposure
Acute toxicity No known effect.
Skin corrosion/irritation No known effect.
Serious eye damage/eye irritation Irritating to eyes.
Skin sensitization No known effect.
Respiratory sensitization No known effect.
Germ cell mutagenicity No known effect.
Neurological Effects No known effect.
Reproductive toxicity No known effect.
Developmental toxicity No known effect.
Teratogenicity No known effect.
STOT - single exposure No known effect.
STOT - repeated exposure No known effect.
Target Organ Effects No known effect.
Aspiration hazard No known effect.
Carcinogenicity No known effect.
For Chemicals → Poly(oxy-1,2-ethanediyl), alpha-sulfo-omega-hydroxy-, C10-16-alkyl ethers, sodium salts, the LD50 listed is >2001 mg/kg. For an average American male (191lb /87 kg ) and American female (159 lb / 72 kg) this works out to 174,000 mg and 144,000 mg.
In simple terms, if 100 American males were to drink greater than 6 oz (174,000 mg), about half of them have a chance of dying. For females the number is 5 oz.
@am77494
Thank you for a much needed voice of sanity and reason on this message board.
Dawn dish detergent (the blue kind) is the standard treatment for de-oiling sea birds and mammals caught in an oil spill. They probably wouldn’t use it if it was toxic.
I think they use Dawn specifically because it’s safer than some of the others. So I’d presume that it varies by product.
I can’t imagine how raw vegetables could absorb enough dishwashing detergent during washing to do you any harm.
I wash vegs like tomatoes, peppers, etc. when I get home. I wash my hands with Ivory soap, rinse, then soap them up again and basically give the vegs a soapy fondle all around, then rinse 'em off.
Give supermarket cucumbers a little extra time, they’re coated with wax, it’s gross.
My chemical engineer cousin-in-law keeps correcting me whenever I don’t use the modern “SDS” term.
So does breathing.
And saponified fats are soaps. IIRC the most common household detergents are alkylbenzene sulfonates.
^^^Well, yeah.
And if you want to be really gross, under many conditions, human bodies saponify as they decompose. Don’t use it (*sometimes called ‘grave wax’) to wash your dishes or vegetables.
Ewwwww😲
Food is made of chemicals. 
So is water and even air. We are clearly doomed.
Remember the adage. The dose makes the poison. Or more completely: “All things are poison, and nothing is without poison; the dosage alone makes it so a thing is not a poison.”
Older types of dishwasher detergents were known for being dangerously alkaline. Great way to clean off fats. Not so good in raw concentrated powder form if eaten. So don’t eat the raw powder.
I would never wash produce with any product that contains an added scent in the first place. I’m sure I’d be able to detect it in the produce even after rinsing.
I’ve read where using a dilute vinegar solution is an option.
Right. Mix it in with your coffee first.
Um, “no known effect” doesn’t mean what you think it does.
I also don’t see how being a “Chemical Engineer” indicates any expertise in toxicology, even if you capitalize it. Some chemical engineers work with OSHA Process Safety Management (PHAs/LOPAs/HAZOPs/HAZIDs/HAZWOPERs), but these all involve evaluation of chemical processes, not of the toxicology of the substances themselves.
Also MSDSs are no longer in use as of 2015.