Toxic is a buzzword. I am not sure how long it has even been around, but it has enough of a kick to get results. If a household product is considered to have health risks, sales plummet. Foods that cause cancer are eschewed. 

Those people who are invested in avoiding such influences in their bodies and homes are motivated to buy differently, and eat alternate food groups. They will pay more for organic produce, and brands without GMOs. Death is in all of our futures, but there is no need to speed the process. And even while many people change their habits because of carcinogens there are others who don't. Often the packaging is attractive, marketing is clever, and the taste is appealing. So it gets tossed in the shopping cart.

I read an article on the Gottman website about three circumstances that can be poisonous to a marriage. One is when a person has an outside relationship that is kept in the shadows. Maybe they work together, and the conversations migrate from the current project to personal information. He or she becomes a confidant, and that increased trust is kept secret from the spouse. 

One book that describes this scenario is called Not Just Friends. Another is Close Calls. The authors offer details about what the dangers are, and how to avoid them. Neither of them prohibit friendships outside of marriage, but they articulate what qualities can unravel commitment. 

Emanuel Swedenborg has a list too. John and I read it in our early years, and it has been a guardrail. He includes such benchmarks as the marriage relationship being like the parent of the other friendship. Also there should not be one person who stands above others, in a special category. Thirdly, what should seem obvious, is that the interactions steer clear of physical expression. 

The sweet part is that within these parameters there is lots of elbow room for affection. Plus the marriage stays as the hub of other friendships.