Posted By Descarte Playing devils advocate for a second, I have no experience in the use of concrete mixers, but do you not require access to these frequently whilst mixing for addition of more water / concrete? Is this the same with your machine, or is it loaded and left? Is the duration in use of a concrete mixer likely to be a great deal shorter than your "slow rotating" type machine. Mixers are usually used outdoors in well ventilated areas, could there also be an issue with yours from an exposure point of view from dust, silica or rusts etc? How many of these machines do you have, 1 or dozens? and are they mobile or fixed? do they need to be moved and removed from site and placed in different location several times a day? I am sure construction sites have polices on clothing and training to ensure no items of clothing etc can be caught up in the equipment whilst in operation. I presume you have the same? I guess if answering all these your machine is very similar to the cement mixer than perhaps it isnt practical to enclose it. Playing devils devils advocate however you could also look at past history, is there precedence of accidents or injuries relating to this bit of equipment on your or similar sites which could have been prevented by enclosure? Does the costs involved outweigh the proposed benefits? Not trying to criticise or be a pain, just offering some thoughts Des

Posted By Tom Doyle Paul, It sounds as if the equipment risk assessment has been performed in accordance with Clause 5 of BS EN ISO 12100-1:2003. If this is the case hazards generated by the moving parts should be guarded. The intent of the risk assessment is to determine what protective measures are both appropriate and practicable for each situation. That being said, I would question the use of fixed barriers. I would think that an interlocked barrier would be more appropriate if access to the hazardous area of the mixer is required. One of the criteria for determining "adequate risk reduction" is deciding if "it certain that the measures taken do not excessively reduce the ability of the machine to perform its function". Take a look at Clause 5 of BS EN ISO 12100-1:2003. It should be helpful in this decision making process. Tom Doyle Industrial Safety Integration