MOM guidelines for protecting employees from haze set out what employers should do at each 24-hour PSI band. At 101 to 200, outdoor work should be reduced or avoided depending on the group of workers, with measures such as job rotation, indoor rest breaks and enough water. At 201 to 300, healthy employees should avoid prolonged or strenuous outdoor work, and where outdoor work cannot be avoided the employer is strongly urged to provide masks; above 300, masks or appropriate respirators should be provided. The guidelines say it is the employer duty to provide suitable masks such as N95 where warranted, to carry out mask fit testing for employees who must still work outdoors, and to keep at least a one-week supply of N95 masks in their haze business continuity plan. Masks make breathing harder, so MOM also tells employers to give regular breaks and keep workers hydrated. If your employer will not provide a mask when you have to work outdoors in poor air, raise it with HR or your union, and you can contact MOM if it is not resolved.