As per IS 10500:2012 drinking water standards, what is the PERMISSIBLE limit (in the absence of any alternate source) for total hardness in drinking water?

• A 1000 mg/L
• B 600 mg/L ✓
• C 400 mg/L
• D 200 mg/L

Explanation

IS 10500:2012 sets the acceptable limit for total hardness at 200 mg/L and the permissible limit in the absence of alternate sources at 600 mg/L. Beyond this, scaling of pipes and unpleasant taste become significant. Option D is the acceptable limit, not the permissible one, and is the classic trap. Nitrate has an acceptable limit of 45 mg/L, which is unrelated to hardness.

Reference: Bureau of Indian Standards, IS 10500:2012, Second revision ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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