Neither the ANSI nor ASTM standards allows for the use of add-on type devices - strap-on foot, toe or metatarsal guards - as a substitute for protective footwear. According to the ANSI and ASTM standards, any protective toe caps or metatarsal guards must be designed, constructed and manufactured into the protective footwear during the manufacturing process and tested as an integral part of the footwear.
While ANSI and ASTM both exclude add-on devices, it doesn’t necessarily mean they’re not acceptable to OSHA. This paradox exists because OSHA states in 1910.136(b)(2) “Protective footwear that the employer demonstrates is at least as effective as protective footwear that is constructed in accordance with one of the above consensus standards will be deemed to be in compliance with the requirements of this section.” This means that if an employer can provide documentation, such as testing data proving their add-on devices provide protection equivalent to either the ANSI or ASTM performance standards, then the add-on devices are acceptable to OSHA. Most manufacturers of add-on devices have submitted their products to independent laboratories for testing. This data and its results can be obtained upon request