OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.

May 26, 1988

  Regional Administrator
  Technical Support
  Directorate of Technical Support
SUBJECT: Hi-Lo "Hard Hat" Radiant Oil Heaters

We have reviewed the materials you sent on the subject heater and contacted the manufacturer for additional information. Based on the information available to use the manufacturer has met the ANSI A10.10 and 29 CFR 1926.154 standards. Both ANSI and OSHA standards require the heater to be equipped with an automatic flame-loss device to stop the flow of fuel if the flame is extinguished. The design of the heater, however, is such that the fuel tank is an integral part of the heater and the fuel cannot flow in case of flame-loss. Therefore the requirement for a flame loss device is not applicable to this specific model.

The manufacturer has stated that the "Hard Hat is designed primarily for use at construction sites and for temporary heating applications. The heater is not intended for use as a permanent fixture. The manufacturer's operating instructions advise that the heater be used in accordance with the Federal, State and local codes and regulations governing temporary heating devices.

The user of this heater in a construction site must comply with the 29 CFR 1926.154 standard. The provisions of the source standard, ANSI A10.10 may be used to cite under the General Duty Clause. ANSI A10.10 in addition to the requirements of 1926.154 requires the following:

1. The heater shall be protected against damage when in use by anchoring or barricading.

2. When used in enclosed or partially enclosed structures, tests for the presence of carbon monoxide shall be made within and hour after the start of each shift and at least four hours thereafter.

3. Carbon monoxide concentrations greater than 50 ppm of air volume at worker breathing levels shall require extinguishing of the heater unless additional mechanical ventilation is provided to reduce the carbon monoxide content to acceptable limits.

4. A qualified employee must be assigned to be responsible for the operation and maintenance of the heater. Instructions on the data plate and all other manufacturer's instructions must be followed.

In general industry, violation of the manufacturer's recommendations, instructions, and warnings may be cited under the General duty Clause after consultation with the Regional Solicitor.