10.5 Safety Codes, Standards & Voluntary Guidelines (OSHA, ANSI, NIOSH, MIL-STD) and DART Rate Calculations

10.5 Safety Codes, Standards & DART Rate Calculations

The specification lists safety codes, standards, and voluntary guidelines (ANSI, OSHA, MIL STD, NIOSH) and DART rate calculations, including the information needed to compute the rate. Industrial engineers design work and workplaces, so they are responsible for building safety into the design and for measuring results.

---

1. Who Writes What

The general duty clause. Section 5(a)(1) of the OSH Act requires each employer to provide a workplace free from recognized hazards likely to cause death or serious physical harm. OSHA uses it when no specific standard applies, often citing consensus standards as evidence that a hazard is recognized.

MIL-STD-882E defines system-safety risk with a matrix of severity (catastrophic, critical, marginal, negligible) and probability (frequent, probable, occasional, remote, improbable, eliminated) and requires hazards to be tracked to acceptance. MIL-STD-1472H gives human engineering design criteria such as control and display arrangement, anthropometric accommodation, workspace dimensions, labeling, and environmental limits.

---

2. The Hierarchy of Controls

NIOSH ranks hazard controls from most to least effective:

1. Elimination: remove the hazard, for example by redesigning a task so no one works at height.
2. Substitution: replace it with something less hazardous, such as a water-based solvent.
3. Engineering controls: isolate people from the hazard with guards, ventilation, lift assists, or interlocks.
4. Administrative controls: change how people work, through procedures, training, job rotation, or warning signs.
5. Personal protective equipment (PPE): gloves, hearing protection, respirators. These are the last line of defense.

Higher levels work regardless of human behavior. PPE fails silently when it is worn incorrectly.

---

3. Key OSHA General Industry Requirements

---

4. OSHA Recordkeeping (29 CFR Part 1904)

Recordable cases are work-related injuries and illnesses that result in any of:

• death
• days away from work
• restricted work or transfer to another job
• medical treatment beyond first aid
• loss of consciousness
• a significant injury or illness diagnosed by a physician or other licensed health care professional

Records:

• Form 300, the log of cases. Column H marks days-away cases, column I job transfer or restriction cases, and column J other recordable cases.
• Form 300A, the annual summary, posted from February 1 to April 30 of the following year.
• Form 301, the incident report for each case.
• Records are kept for 5 years. Many employers with 10 or fewer employees, and certain low-hazard industries, are partially exempt.

Day counting: count calendar days away or restricted, not including the day of injury, and cap each case at 180 days.

Reporting: call OSHA within 8 hours of a work-related fatality, and within 24 hours of an in-patient hospitalization, an amputation, or the loss of an eye.

---

5. Incidence Rate Calculations

All OSHA rates are normalized to 200,000 hours, the hours worked by 100 full-time employees in a year (40 hours/week × 50 weeks):

$\text{Rate} = \frac{\text{Number of cases (or days)} \times 200{,}000}{\text{Total hours worked by all employees}}$

Use actual hours worked from payroll records, including overtime and excluding vacation, holiday, and sick leave.

Worked example: A plant with about 450 employees worked 925,000 hours last year. Its 300 log shows 14 recordable cases: 5 with days away (78 days total), 3 with restricted work or transfer (40 days total), and 6 other recordable cases.

• TRIR $= 14 \times 200{,}000 / 925{,}000 = 3.03$
• DART $= (5 + 3) \times 200{,}000 / 925{,}000 = 1.73$
• Days-away case rate $= 5 \times 200{,}000 / 925{,}000 = 1.08$
• Lost-workday severity $= 78 \times 200{,}000 / 925{,}000 = 16.9$ days away per 100 full-time workers

Compare rates with the Bureau of Labor Statistics averages for the plant's NAICS industry, and track trends. A low TRIR with a high severity rate suggests fewer but more serious injuries.