If you're interested in the biological or health effects of various chemicals, try to look up the Safety Data Sheet, or "SDS" or "MSDS", for that chemical compound.
Going to your favorite search engine and plugging in your chemical of interest to the search term "SDS" or "MSDS" will almost always get you to some kind of answer — either what you're looking for has a safety data sheet or it doesn't!
In the case of 70% isopropyl alcohol, there are SDSs/MSDSs out there that will tell you what potential health effects are. Here's one example for 70% isopropyl alcohol:
Potential Health Effects
Eye: Produces irritation, characterized by a burning sensation, redness, tearing, inflammation, and possible corneal injury. May cause transient corneal injury. In the eyes of a rabbit, 0.1 ml of 70% isopropyl alcohol caused conjunctivitis, iritis, and corneal opacity.
Skin: May cause irritation with pain and stinging, especially if the skin is abraded. Isopropanol has a low potential to cause allergic skin reactions; however, rare cases of allergic contact dermatitis have been reported. May be absorbed through intact skin. Dermal absorption has been considered toxicologically insignificant. The cases of deep coma associated with skin contact are thought to be a consequence of gross isopropanol vapor inhalation in rooms with inadequate ventilation, rather than being attributable to percutaneous absorption of isopropanol per se.
Ingestion: Causes gastrointestinal irritation with nausea, vomiting and diarrhea. May cause kidney damage. May cause central nervous system depression, characterized by excitement, followed by headache, dizziness, drowsiness, and nausea. Advanced stages may cause collapse, unconsciousness, coma and possible death due to respiratory failure. Aspiration of material into the lungs may cause chemical pneumonitis, which may be fatal. The probable oral lethal dose in humans is 240 ml (2696 mg/kg), but ingestion of only 20 ml (224 mg/kg) has caused poisoning.
Inhalation: Inhalation of high concentrations may cause central nervous system effects characterized by nausea, headache, dizziness, unconsciousness and coma. May cause narcotic effects in high concentration. Causes upper respiratory tract irritation. Inhalation of vapors may cause drowsiness and dizziness.
Chronic: Prolonged or repeated skin contact may cause defatting and dermatitis.
Safety data sheets sound terrible! But in reality, people use rubbing alcohol with common sense, without putting into their eyes, without drinking it, etc.
Mainly the point of this answer is to help you find the answer for yourself, if you want to find out about this or other chemicals you might be worried about.
