Warning signs shall be printed in red on white background and shall contain the following statement in letters not less than two inches in height: “DANGER—FUMIGATION.” They shall also depict a skull and crossbones not less than one inch in height and shall state in letters not less than one-half inch in height the name of the fumigant. These signs shall also include in legible ink of any color, the date and time fumigant was injected, and the name, address, and telephone number of the registered company performing the fumigation. Warning signs placed under a tarpaulin shall not be required to state the time the fumigant was injected.