ISO 17491-4:2008 specifies methods for determining the resistance of chemical protective clothing to penetration by sprays of liquid chemicals at two different levels of intensity:

• Method A: low-level spray test. This is applicable to clothing that covers the full body surface and which is intended to be worn when there is a potential risk of exposure to small quantities of spray or accidental low volume splashes of a liquid chemical.
• Method B: high level spray test This is applicable to clothing with spray-tight connections between different parts of the clothing and, if applicable, between the clothing and other items of personal protective equipment, which covers the full body surface and which is intended to be worn when there is a risk of exposure to sprayed particles of liquid.