Workplace politeness concerns the structural, interactional and individual level. Using the example of mobbing, it is illustrated how small acts of impoliteness can lead to the destruction a person psychologically and physically. Particularly, so-called downward mobbing is an increasing problem worldwide; most of the cases are orchestrated by superiors, the people subordinates depend on the most. Data clearly illustrate the social toxin created by up to 45 seemingly small actions in five areas of work life. These actions result in health hazards and ultimately loss of jobs. By example of workplace harassment, it is illustrated how systematic acts of impoliteness are used to manipulate a person's emotion and identity, to ensure anxiety-born solidarity in others while abusing power, with high costs for the target, the organisation, and society. The discussion gives way to considerations about intercultural cooperation at the workplace, showing similarities between subtle devaluations in intercultural communication called microaggression and what has been discussed as mobbing. Overall, impoliteness is deconstructed as a sign of degrading social bonds, security and health, thereby raising awareness of the importance of intercultural interaction without microaggression. The practical value of linguistic impoliteness research and its connection to work psychology becomes apparent.