Greenhouse Ventilation Criteria

If ventilation restrictions apply, employers must ensure that one of the following ventilation criteria is met:

• The concentration of the pesticide in the air is measured to be less than or equal to any inhalation exposure level required on the label.
• If no inhalation exposure level is listed on the pesticide label, keep workers out until after ten air exchanges; two hours of ventilation using fans or other mechanical ventilating systems; four hours of ventilation using vents, windows, or other passive ventilation; 11 hours with no ventilation followed by one hour of mechanical ventilation; 11 hours with no ventilation followed by two hours of passive ventilation; or 24 hours with no ventilation.

After ventilation criteria are met and until the restricted-entry interval expires, employers must not allow workers into the treated area. Workers may, however, be allowed in the areas just outside of the treated area that were off-limits during the application.

To learn more about Pesticide Worker Safety visit our Pesticide Worker Safety Online Training web page.