**Core Concept**
The Occupational Safety and Health Administration (OSHA) has established threshold limit values (TLVs) for various workplace chemicals, including mercury, to protect workers from hazardous exposures. TLVs represent the maximum airborne concentration of a substance that is considered safe for an 8-hour workday and a 40-hour workweek.

**Why the Correct Answer is Right**
The TLV for mercury exposures is set at 0.05 mg/m³ to minimize the risk of mercury toxicity, which can cause neurological damage, kidney damage, and other health problems. Mercury is a potent neurotoxin that can accumulate in the body and cause long-term harm. The TLV for mercury is based on the American Conference of Governmental Industrial Hygienists (ACGIH) recommendations, which take into account the potential health effects of mercury exposure.

**Why Each Wrong Option is Incorrect**
**Option A:** 0.01 mg/m³ is too low to be a reasonable TLV, as it would likely be unachievable in many workplaces and would not provide adequate protection for workers.
**Option C:** 0.1 mg/m³ is too high, as it would increase the risk of mercury toxicity and health problems for workers.
**Option D:** 0.001 mg/m³ is an extremely low value, which is not practical or necessary for protecting workers from mercury exposure.

**Clinical Pearl / High-Yield Fact**
It's essential to note that the TLV for mercury is not the same as the permissible exposure limit (PEL), which is a legal limit set by OSHA. The PEL for mercury is also 0.05 mg/m³, but it's enforced more strictly than the TLV.

**✓ Correct Answer: B. 0.05 mg/ m3**