Does a defendant have a duty to instruct on his own motion concerning accident as an affirmative defense?

With respect to CALJIC No. 4.45, although acknowledging that he did not request this instruction, defendant contends the trial court had a duty to instruct on its own motion concerning accident as an affirmative defense. (See People v. Breverman, supra, 19 Cal.4th at p. 157, 77 Cal.Rptr.2d 870, 960 P.2d 1094 [discussing the limited duty of a trial court to instruct on its motion concerning defenses].) A claim of accident in response to a charge of murder, however, is not an affirmative defense that can trigger a duty to instruct on the court's own motion.