It is a civil rights violation:
For the purposes of this subdivision (A-5), "language" means a person's native tongue, such as Polish, Spanish, or Chinese. "Language" does not include such things as slang, jargon, profanity, or vulgarity.
Nothing in this Section prohibits an employer from enacting a dress code or grooming policy that may include restrictions on attire, clothing, or facial hair to maintain workplace safety or food sanitation.
For the purposes of this subdivision (J), "reasonable accommodations" means reasonable modifications or adjustments to the job application process or work environment, or to the manner or circumstances under which the position desired or held is customarily performed, that enable an applicant or employee affected by pregnancy, childbirth, or medical or common conditions related to pregnancy or childbirth to be considered for the position the applicant desires or to perform the essential functions of that position, and may include, but is not limited to: more frequent or longer bathroom breaks, breaks for increased water intake, and breaks for periodic rest; private non-bathroom space for expressing breast milk and breastfeeding; seating; assistance with manual labor; light duty; temporary transfer to a less strenuous or hazardous position; the provision of an accessible worksite; acquisition or modification of equipment; job restructuring; a part-time or modified work schedule; appropriate adjustment or modifications of examinations, training materials, or policies; reassignment to a vacant position; time off to recover from conditions related to childbirth; and leave necessitated by pregnancy, childbirth, or medical or common conditions resulting from pregnancy or childbirth.
For the purposes of this subdivision (J), "undue hardship" means an action that is prohibitively expensive or disruptive when considered in light of the following factors:
No employer is required by this subdivision (J) to create additional employment that the employer would not otherwise have created, unless the employer does so or would do so for other classes of employees who need accommodation. The employer is not required to discharge any employee, transfer any employee with more seniority, or promote any employee who is not qualified to perform the job, unless the employer does so or would do so to accommodate other classes of employees who need it.
775 ILCS 5/2-102