Risk of spreading illnesses
As we've already mentioned, people with poor personal hygiene are likely to put their colleagues at risk of catching viruses and diseases (not just COVID-19). If 2 or 3 staff members have to go on sick leave due to an outbreak of sickness in the office, that could put a lot of pressure on those left behind. If everyone is conscious of their personal hygiene in the workplace, it dramatically reduces the risk of mass illnesses in the workforce.
The face of the business
Whether you work in an office, a shop, a restaurant or a laboratory - you are the face of your business. If you're in any role that's customer or client-facing then it's vital that you maintain a good level of personal hygiene because you're representing your company. People who are motivated to progress within their company are likely to take their personal hygiene seriously because they want to be involved in important meetings etc. If you take pride in your appearance and hygiene, it shows that you care about your work and want to portray yourself professionally, so don't slack on your personal hygiene if you're looking for a promotion!
Relationships with colleagues
Chances are if you're someone who regularly turns up to work unclean (and potentially smelly) then people are going to have a hard time interacting with you. If you want to build better relationships with your colleagues it's important that you maintain good personal hygiene. This includes washing your hair, brushing your teeth, wearing clean clothes and keeping your workspace tidy. More often than not, people who are messy are also disorganised and your mess might even distract the people sitting around you. So, if you want to have better relationships with people at work, make sure you're putting some time and effort into your personal hygiene.