First 2 in each heat (Q) and the next 2 fastest (q)

First 2 of each heat (WQ) plus 2 fastest times (Wq) qualify to World Athletics Championships and World Athletics Relays Final

POS Rank Heat BIB ATHLETE COUNTRY RESULTS
1 1 2 ESP Spain ESPESP 42.18 WQ NR
2 2 2 JAM Jamaica JAMJAM 42.51 WQ SB
3 1 1 BEL Belgium BELBEL 42.80 WQ SB
4 1 3 USA United States USAUSA 42.86 WQ
5 2 1 GBR Great Britain & NI GBRGBR 42.92 WQ SB
6 3 2 GER Germany GERGER 42.98 Wq SB
7 2 3 CAN Canada CANCAN 43.11 WQ
8 3 3 NED Netherlands NEDNED 43.13 Wq SB
9 3 1 AUS Australia AUSAUS 43.15
10 4 1 FRA France FRAFRA 43.29 SB
11 4 3 ITA Italy ITAITA 43.30 SB
12 5 1 CHI Chile CHICHI 43.64 NR
13 5 3 POR Portugal PORPOR 44.18 SB
14 6 1 CIV Côte d’Ivoire CIVCIV 44.85 SB
2 LBR Liberia LBRLBR DNF
3 SUI Switzerland SUISUI DNF
2 POL Poland POLPOL DQ
2 CHN PR of China CHNCHN DQ