Federal law (29 CFR 1606.7(a) greatly restricts the extent to which English-only rules are acceptable. Federal law provides that a rule requiring employees to speak English only at all times (including breaks and meal periods, as you noted) is a burdensome term and condition of employment For an English-only rule to be acceptable while the employees are actually working, it would need to be narrowly tailored to address business necessity. Situations in which business necessity would justify an English-only rule would include:
- For communications with customers, coworkers, or supervisors who only speak English. This doesn't mean you can require employees to speak English at all times because some workers don't speak an alternate language; it means that you can require an employee to speak English when speaking directly to an employee who speaks only English.
- In emergencies or other situations in which employees must speak a common language to promote safety. For instance, a rule requiring employees to speak only English in the event of an emergency and when performing their work in specific areas of the workplace that might contain flammable chemicals or other potentially dangerous equipment is narrowly tailored to safety requirements and does not violate Title VII.
- For cooperative work assignments in which the English-only rule is needed to promote efficiency. For example a rule requiring investigators (some of whom only speak English) to speak only English when working as a team to compile a report or prepare a case for litigation would not likely violate Title VII.
- To enable a supervisor who only speaks English to monitor the performance of an employee whose job duties require communication in English with coworkers or customers. A rule requiring employees to speak only English with English speaking coworkers and customers when a supervisor is present to modify their work performance would be narrowly tailored to promote the efficiency of business operations, but the rule would not be able to apply to employees' casual conversations when they are not performing job duties.
The fact that other employees feel uncomfortable when coworkers converse in another language is not reason enough for an English-only rule.