Assessment of Flame Retardancy of Polyurethane Foam Used in Furniture Manufacturing in Aba, Abia State

Polyurethane foam is extensively used in upholstered furniture manufactured in Aba, Abia State, one of Nigeria's most active industrial cities in South East Nigeria. However, concerns about fire safety performance of locally produced foam have not been systematically addressed. This study assesses the flame retardancy of polyurethane foam samples collected from twelve furniture manufacturers in Aba, evaluating whether flame retardant additives are incorporated and at what efficacy levels. Foam samples were subjected to horizontal and vertical burning tests in accordance with ASTM D1692 and FMVSS 302 standard methods. Limiting oxygen index measurements were conducted to quantify the minimum oxygen concentration required to sustain combustion. Scanning electron microscopy and energy-dispersive X-ray spectroscopy were employed to identify additive presence and chemical composition of residual char after burning. Results reveal that only three of twelve manufacturers incorporated flame retardant additives in their foam formulations. Untreated foam samples exhibited limiting oxygen index values as low as 17.2 percent, indicating high flammability under ambient conditions. Vertical burn tests showed rapid flame propagation in unprotected samples, with burn lengths exceeding 200 mm in less than 30 seconds. Char residue analysis confirmed the absence of phosphorus or nitrogen-based flame retardants in non-treated samples. The study recommends mandatory flame retardant specifications in procurement standards for foam used in public furniture, as well as regulatory enforcement by the Standards Organisation of Nigeria to protect consumers from fire hazard risks in South East Nigeria. Keywords: polyurethane foam, flame retardancy, limiting oxygen index, Aba, furniture safety