Title Are used goods imported by passengers liable to Customs duty charges?

Yes. All goods whether new or use, are subject to taxation. However different passenger categories have different concession and entitlements as here below;

Passenger Categorization
Category A. - This category includes all passengers on the first arrival who are bona fide changing their residences to Kenya whether as missionaries, military personnel or Aid Agencies or to take up appointments in commerce or industry. It also includes diplomats, students and other persons resident in Kenya but who have resided outside Kenya for a period long enough as prescribed to enable them to comply with the conditions prescribed in Parts A and B of the Fifth Schedule of EACCMA.
a) wearing apparel;
b) personal and household effects of any kind which were in his personal or household use in his former place of residence;
c) one motor vehicle, which the passenger has personally owned and used outside a Partner State for at least twelve months (excluding the period of the voyage in the case of shipment)

Category B. - Bona fide tourists and visitors to Kenya for periods not exceeding three months. This category includes not only tourists but temporary business and other visitors. Kenya Government has directed that every reasonable facility is to be given to such passengers in the interests of the tourist industry.
a) Non-consumable goods imported for his personal use during his visit which he intends to take out with him when he leaves at the end of his visit;
b) Consumable provisions and non-alcoholic beverages in such quantities and of such kinds as are inconsistent with his visit;
c) That the goods are imported by a returning resident being an employee of an international organization the headquarters of which are in a Partner State and who has been recalled for consultations at the organization?s headquarters.

Category C. - All returning Kenyan residents and passengers not included in Categories A and B above.
a) Wearing apparel;
b) Personal and household effects which have been in his personal use or household use.
Subject to the above entitlements, duty shall not be levied on the following goods imported by, and in the possession of a passenger:-
a) Spirits (including liquors) or wine, not exceeding one litre or wine not exceeding two litres;
b) perfume and toilet water not exceeding in all one-half litre, of which not more than a quarter may be perfume;
c) Cigarettes, cigars, cheroots, cigarillos, tobacco and snuff not exceeding in all 250 grammes in weight.

The import duty-free allowance shall be granted only to passengers who have attained the age of (18) eighteen years.

Category Customs