Judgment, Supreme Court, New York County, entered October 7, 1972, in favor of plaintiffs on the issue of liability, is unanimously reversed, on the law, and vacated, and a new trial directed, with $60 costs and disbursements to abide the event. The trial court’s charge to the jury ón contributory negligence constituted reversible error. The court, at the request of counsel for the defendant, charged the jury: “Contributory negligence, to be a bar to this action need not be a substantial factor. Any contributory negligence contributing to the happening of the accident, no matter how slight, will bar recovery on the part of the plaintiff.” Immediately thereafter, upon request of counsel for the plaintiff, the court charged that: “Contributory negligence * ® * to be a bar to [plaintiffs’] recovery, must [be] * * * [the] proximate cause of the accident and that a proximate cause of an accident is defined as one which is a substantial factor in 1 inging about the accident.” Such charge, without further elaboration on the relevance of the term “ substantial factor ”, has been held to be error time and again.- (Gill v. Anderson, 39 A D 2d 941; Siegelman v. Truehon, 39 A D 2d 722; Maggio v. Mid-Hudson Chevrolet, 34 A D 2d obi) Ortiz v. Kinoshita & Co., 30 A D 2d 334; Bacon v. Celeste, 30 A D -3d 324.) As noted in the cases above cited, the problem with such charge, while perhaps technically correct, is that the use of the term “substantial factor” with respect to proximate cause may be considered by the jury to mean that plaintiff’s contributory negligence will bar recovery only if it is substantial in degree which, of course, is contrary to New York law. Hence, as discussed in Bacon V. Celeste (supra) when the words “ substantial factor ” are used in a charge in a negligence case, they should be used “ only in relation to a proper and adequate discussion of the issue of causal- relation or proximate cause”. (Bacon v. Celeste, supra, p. 325.) The charge herein was not limited in such manner nor was there adequate clarification of the terms used. Concur — Stevens, P. J., Murphy, Lane, Steuer and Tilzer, JJ.