What are some types of toxic cookware to avoid and safe alternatives?

Anything with PTFE or Teflon and Aluminium. Teflon is carcinogenic ( causes cancer ) when it flakes off and burns. Its non stick properties make it popular, but on GAS stoves people can easily burn the PTFE off.
Though many say other wise – Aluminium maybe linked to Alzheimer’s and will react with sulphur based foods like eggs and some greens, but also acidic foods such as fruits. Despite nearly every one saying – there is no link between aluminium and alzheimer’s – I have listed some science papers stating that there could be a link based on new findings. So if in doubt throw it out.
https://www.dementia.org.au/files/helpsheets/Helpsheet-DementiaQandA19-Aluminium_english.pdf
Aluminum exposure and Alzheimer’s disease.
Aluminum and Alzheimer’s disease: a new look.
The association of aluminum Alzheimer’s disease, and neurofibrillary tangles.
The risks of Aluminium cookware was warned about as far back as the 1950’s and manufacturers ignored it as it was CHEAP and no science evidence was made available. In time PTFE was placed over it as a low cost non-stick coating. however in recent years PTFE has become suspect – more so if it is over heated and flakes off. Here is one such article >
PTFE-coated non-stick cookware and toxicity concerns: a perspective.
As there is controversy on the above – I would recommend – Stainless steel, cast iron ( mainly for roasting / baking as it rusts easily ), porcelain china, baked clay, and pyrex glass – are the only ones I’d use for regular cooking.
Stainless being the most durable and costly. If you burn them they still work well and don’t give off toxic chemicals – as far as I’m aware.
Most quality cookware is stainless or may include a copper or aluminium insert base for heat conduction, but not as part of the food vessel area.
However if oil is used in the PTFE or Aluminium and the temperature is kept low, or it’s used for roasting then you will be ok.
With stainless steel – good quality stainless is not magnetic or very low at best, so when buying pots – take a small bar magnet with you.
Also use FOOD GRADE stainless which is coded as 304 and 316. 316 is for high corrosion resistant applications where salt is to be used. 304 is regular food grade stainless. So for example if you were cooking in sea water for certain seafood dishes or add salt to the water as my mother did, – then I would use 316 not 304.
if you were using normal tap water that had a balanced ph, then stainless 304 would be fine. Though this may sound technical – err on the side of caution and just outlay a bit extra and purchase 316 stainless pots for 99% of everyday cooking. > 3 Things You Need to Know About Food-Grade Stainless Steel

10 Pcs Non Stick Cooking Set w/ Frying Pans & Saucepans