Additional information:
- hydrochloric acid: Concentrated hydrochloric acid (fuming hydrochloric acid) forms acidic mists. Both the mist and the solution have a corrosive effect on human tissue, with the potential to damage respiratory organs, eyes, skin, and intestines irreversibly. Upon mixing hydrochloric acid with common oxidizing chemicals, such as sodium hypochlorite (bleach, NaClO) or potassium permanganate (KMnO4), the toxic gas chlorine is produced.
- polyacrylamide: Concerns have been raised that polyacrylamide used in agriculture may contaminate food with the nerve toxin acrylamide.
- Ethylene glycol (the stuff in antifreeze): Ethylene glycol is moderately toxic with an oral LDLO = 786 mg/kg for humans.[8] The major danger is due to its sweet taste. Because of that, children and animals are more inclined to consume large quantities of it than of other poisons. Upon ingestion, ethylene glycol is oxidized to glycolic acid which is, in turn, oxidized to oxalic acid, which is toxic. It and its toxic byproducts first affect the central nervous system, then the heart, and finally the kidneys. Ingestion of sufficient amounts can be fatal if untreated.
- glutaraldehyde: As a strong disinfectant, glutaraldehyde is toxic and a strong irritant
- Isopropyl alcohol (I think this stuff is in aerosol deodorant and hairspray): Isopropyl alcohol and its metabolite, acetone, act as central nervous system (CNS) depressants. Symptoms of isopropyl alcohol poisoning include flushing, headache, dizziness, CNS depression, nausea, vomiting, anesthesia, and coma.
I am not familiar with all of those, but hydrochloric acid, ethylene glycol, and isopropyl alcohol will decompose to basic elements within days if not hours.
The are only dangerous if you actually ate the concentrated solution. Put them in the ground, and they'll be harmless within days - really, days - hours even for some of them.
I looked up the other two.
Polyacrylamide is used in water treatment. Yes, the water you drink, and it's used in soft contact lenses, and mixed into soil on farms. The concern is from the potential 0.05% contamination, and in the small amounts used, plus the dilution underground 0.05% is nothing.
Oh, and on top of that acrylamide decomposes rapidly in soil so there will be none left by the time it reaches the surface.
I looked up glutaraldehyde and it decomposes within 48 hours in the presence of oxygen, and 24 hours to a week without oxygen.
I guess I should thank you for posting this, because if this is the extent of the worrisome chemicals used then there is nothing to worry about - all them are completely harmless within days. For some reason I thought they were using dangerous chemicals, but I guess not.
Edit: source: http://en.wikipedia.org/wiki/Proppants_and_fracking_fluids
They apparently don't just use water, like some people might expect they could, because it doesn't work. Many people are concerned about contamination from the fracking fluid, correctly or not.