My employee wants me to pay for a very expensive air purifier/humidifier for her office as a reasonable accommodation to due to her recent lung transplant and her medical requirement to have humidified air – do I have to pay for this?

The answer is likely yes.   Under the American’s With Disabilities Act (ADA), an employer is responsible for making facilities accessible to qualified employees with disabilities unless it would pose an undue hardship.  The question here is whether the cost of the air purifier/humidifier is an undue hardship to the employer.  As a general rule of thumb, if an employer uses cost as reason not to provide an accommodation, it needs to be prepared to open up its financial records and prove that it doesn’t spend money in a more frivolous way.  For example, is the cost of the company holiday party or summer picnic more expensive than this air purifier?  If the answer is yes, the employer will have a difficult time proving that the cost of this air purifier is an undue hardship.  In addition, the employer should consider whether the potential cost of litigation would far exceed the cost of providing this necessary accommodation.